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  • 51.
    Bennett, N. C.
    et al.
    Univ Pretoria, South Africa.
    Ganswindt, A.
    Univ Pretoria, South Africa.
    Ganswindt, S. B.
    Univ Pretoria, South Africa.
    Jarvis, J. U. M.
    Univ Cape Town, South Africa.
    Zöttl, Markus
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM). Univ Cambridge, UK.
    Faulkes, C. G.
    Queen Mary Univ London, UK.
    Evidence for contrasting roles for prolactin in eusocial naked mole-rats, Heterocephalus glaber and Damaraland mole-rats, Fukomys damarensis2018Ingår i: Biology Letters, ISSN 1744-9561, E-ISSN 1744-957X, Vol. 14, nr 5, artikel-id 20180150Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Elevated prolactin (PRL) has been associated with the expression of social and cooperative behaviours in a number of vertebrate species, as well as suppression of reproduction. As social mole-rats exhibit both of these traits, PRL is a prime candidate in mediating their social phenotype. While naked and Damaraland mole-rats (NMRs and DMRs) have evolved eusociality independently within their family, both species exhibit an extreme skew in lifetime reproductive success, with breeding restricted to a single female and one or two males. Non-breeding NMRs of both sexes are physiologically inhibited from reproducing, while in DMRs only the non-breeding females are physiologically suppressed. Newly emerging work has implicated the dopamine system and PRL as a component in socially induced reproductive suppression and eusociality in NMR, but the DMR remains unstudied in this context. To investigate evolutionary convergence in the role of PRL in shaping African mole-rat eusociality, we determined plasma PRL concentrations in breeders and non-breeders of both sexes, comparing DMRs with NMRs. Among samples from non-breeding NMRs 80% had detectable plasma PRL concentrations. As a benchmark, these often (37%) exceeding those considered clinically hyperprolactinaemic (25 ng ml(-1)) in humans: mean +/- s.e.m.: 34.81 +/- 5.87 ngml(-1); range 0.00-330.30 ng ml(-1). Conversely, 85% of non-breeding DMR samples had undetectable values and none had concentrations above 25 ng ml(-1): 0.71 +/- 0.38 ng ml(-1); 0.00-23.87 ngml(-1). Breeders in both species had the expected variance in plasma PRL concentrations as part of normal reproductive function, with lactating queens having significantly higher values. These results suggest that while elevated PRL in non-breeders is implicated in NMR eusociality, this may not be the case in DMRs, and suggests a lack of evolutionary convergence in the proximate control of the social phenotype in these mole-rats.

  • 52.
    Berggren, Hanna
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Nordahl, Oscar
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Tibblin, Petter
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Larsson, Per
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Forsman, Anders
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Testing for local adaptation to spawning habitat in sympatric subpopulations of northern pike by reciprocal translocation of embryos2016Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, nr 5, artikel-id e0154488Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We tested for local adaption in early life-history traits by performing a reciprocal translocation experiment with approximately 2500 embryos of pike (Esox lucius) divided in paired split-family batches. The experiment indicated local adaptation in one of the two subpopulations manifested as enhanced hatching success of eggs in the native habitat, both when compared to siblings transferred to a non-native habitat, and when compared to immigrant genotypes from the other subpopulation. Gene-by-environment effects on viability of eggs and larvae were evident in both subpopulations, showing that there existed genetic variation allowing for evolutionary responses to divergent selection, and indicating a capacity for plastic responses to environmental change. Next, we tested for differences in female life-history traits. Results uncovered that females from one population invested more resources into reproduction and also produced more (but smaller) eggs in relation to their body size compared to females from the other population. We suggest that these females have adjusted their reproductive strategies as a counter-adaptation because a high amount of sedimentation on the eggs in that subpopulations spawning habitat might benefit smaller eggs. Collectively, our findings point to adaptive divergence among sympatric subpopulations that are physically separated only for a short period during reproduction and early development – which is rare. These results illustrate how combinations of translocation experiments and field studies of life-history traits might infer about local adaptation and evolutionary divergence among populations. Local adaptations in subdivided populations are important to consider in management and conservation of biodiversity, because they may otherwise be negatively affected by harvesting, supplementation, and reintroduction efforts targeted at endangered populations.

  • 53.
    Bergström, Kristofer
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Impact of Using Macroalgae from the Baltic Sea in Biogas Production: A Review with Special Emphasis on Heavy Metals2012Självständigt arbete på avancerad nivå (masterexamen), 30 poäng / 45 hpStudentuppsats (Examensarbete)
    Abstract [en]

    A consequence of eutrophication in the Baltic Sea is growth of algae that accumulates in the coastal areas and beaches. Dense algal mats may cause anoxia or hypoxia and greatly reduce the recreational value of the area. Algae also functions as hyper accumulators of heavy metals and their metal levels may become toxic to higher trophic levels. The project Wetlands, Algae and Biogas (WAB) aims at removing algal beach cast for commercial use in biogas production and further use of the fermentation residues as fertilizer. Collection of algae would remove both nutrients and heavy metals from the Baltic Sea but leave us with large amounts of algae containing heavy metals. A concern for the biogas production based on these Baltic algae is the effects from the heavy metals, during fermentation, in the residues and the use of them as fertilizer. A literature review shows that the levels of heavy metals should not inhibit the biogas production but during the fermentation there is a loss of (48%) biological material and the metals are concentrated in the residues. Samples of algae from Trelleborg (SE) show higher concentrations of cadmium (Cd) than algae from Poland (PL). The Swedish residues border or surpass the legislative amount of heavy metals that are allowed to be applied to arable land in Sweden. This is both due to the higher concentrations of heavy metals and the differences between European and Swedish legislation. To use the residues as fertilizer detoxification is required, mainly for Cd in Sweden. There are effective methods, chemicals and ion exchangers (70-80%), for removing heavy metals from organic leachate. But these methods lack testing on a large scale, the costs and the environmental aspect of these methods on tons of algae per year are unknown. Co-fermentation with a suitable substrate would dilute the heavy metal concentration and could reduce possible problems such as hydrogen sulfide accumulation in the biogas. Another possible pathway for dealing with the heavy metal rich residues is as fertilizer for non-food crops such as the biofuel species willow (Salix). Willow is a fast growing tree that is a known accumulator of heavy metals and can be used as a remediation for contaminated soil. Based on the metal concentrations and respective legislation, estimations of 20 000 ha of willow for Trelleborg and 400 ha for Sopot beach (PL) is needed to process harvested algae. 

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  • 54.
    Bergström, Kristofer
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Rapid Changes in Salinity and Cyanobacterial Exposure Influence condition of Young of the Year (YOY) Perch (Perca fluviatilis): A Field Study in the Curonian Lagoon(Lithuania)2010Självständigt arbete på avancerad nivå (magisterexamen), 30 poäng / 45 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Two decades ago the recruitment of YOY perch (Perca fluviatilis) started to decline along the Swedish east cost of the Baltic Sea. Factors that influence recruitment are e.g. eutrophication that causes habitat losses and overfishing of cod (Gadus morhua) which causes cascading effects in the food web. Filamentous cyanobacterial blooms are often toxic and has increased in the Baltic Sea and its coastal waters. The aim of this field study was to evaluate the effects of salinity and cyanobacterial exposure on fitness related parameters of young of the year (YOY) perch (Perca Fluviatilis) in a natural environment. Our study was performed in the Curonian Lagoon (Lithuania) in August 2009. The lagoon offers a temporary salinity gradient (wind induced influxes from the Baltic Sea) ranging from 7 psu in the north to 0 psu in the south. Submerged enclosures containing YOY perch were set up at three different locations along the salinity gradient in the Lagoon (referred to as North, Middle, South). The duration of the experiment was 21 or 27 days, depending on treatment. Measurements of perch condition were specific growth rate, somatic condition index (SCI) and whole fish lipid and protein content. Average chl a values for the three stations during the experimental time were: north 180 ± 70 µg/l chl a, middle 133 ± 36 µg/l chl a and south 180 ± 52 µg/l chl a. The North and the Middle stations experienced two different salinity influxes reaching a maximum salinity of 6.5 psu at the northern station. The duration of each saline influx was approximately 4-6 days. The saline water did not reach the Southern station at any time. Results show that perch from the southern station were in best condition in terms of specific growth rate and contents of total lipids. Compared to the South the perch condition declined to the Middle station and was lowest at the Northern station which experienced the highest degree of fluctuation in terms of salinity and cyanobacterial exposure. Examination of the abundance of the main food resource at the different stations revealed no statistical differences, which suggest that availability of food was not a factor in explaining the differences in growth.  The results possibly indicate that a changing environment with the potential synergistic negative effects of salinity and cyanobacteria has a higher negative impact on YOY perch condition compared to constantly high concentrations of cyanobacteria.

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  • 55.
    Berner, Christoffer
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Bertos-Fortis, Mireia
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Pinhassi, Jarone
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Legrand, Catherine
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Response of Microbial Communities to Changing Climate Conditions During Summer Cyanobacterial Blooms in the Baltic Sea2018Ingår i: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 9, artikel-id 1562Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Frequencies and biomass of Baltic Sea cyanobacterial blooms are expected to be higher in future climate conditions, but also of longer duration as a result of increased sea surface temperature. Concurrently, climate predictions indicate a reduced salinity in the Baltic Sea. These climate-driven changes are expected to alter not solely the phytoplankton community but also the role of microbial communities for nutrient remineralization. Here, we present the response of summer plankton communities (filamentous cyanobacteria, picocyanobacteria, and heterotrophic bacteria) to the interplay of increasing temperature (from 16 to 18 degrees C and 20 degrees C) and reduced salinity (from salinity 6.9 to 5.9) in the Baltic Proper (NW Gotland Sea) using a microcosm approach. Warmer temperatures led to an earlier peak of cyanobacterial biomass, while yields were reduced. These conditions caused a decrease of nitrogen-fixers (Dolichospermum sp.) biomass, while non nitrogen-fixers (Pseudanabaena sp.) increased. Salinity reduction did not affect cyanobacterial growth nor community composition. Among heterotrophic bacteria, Actinobacteria showed preference for high temperature, while Gammaproteobacteria thrived at in situ temperature. Heterotrophic bacteria community changed drastically at lower salinity and resembled communities at high temperature. Picocyanobacteria and heterotrophic bacterial biomass had a pronounced increase associated with the decay of filamentous cyanobacteria. This suggests that shifts in community composition of heterotrophic bacteria are influenced both directly by abiotic factors (temperature and salinity) and potentially indirectly by cyanobacteria. Our findings suggest that at warmer temperature, lower yield of photosynthetic cyanobacteria combined with lower proportion of nitrogen-fixers in the community could result in lower carbon export to the marine food web with consequences for the decomposer community of heterotrophic bacteria.

  • 56.
    Bernes, Claes
    et al.
    Royal Swedish Academy of Sciences.
    Carpenter, Stephen
    University of Wisconsin, USA.
    Gårdmark, Anna
    Swedish University of Agricultural Sciences.
    Larsson, Per
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Persson, Lennart
    Umeå University.
    Skov, Christian
    Technical University of Denmark, Denmark.
    Speed, James
    Norwegian University of Science and Technology, Norway.
    Van Donk, Ellen
    Netherlands Institute of Ecology, Netherlands.
    What is the influence of a reduction of planktivorous and benthivorous fish on water quality in temperate eutrophic lakes?2015Ingår i: Environmental Evidence, ISSN 2047-2382, E-ISSN 2047-2382, Vol. 4, s. 1-28, artikel-id 7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background

    In recent decades, many attempts have been made to restore eutrophic lakes through biomanipulation. Reducing the populations of planktivorous and benthivorous fish (either directly or through stocking of piscivorous fish) may induce ecosystem changes that increase water transparency and decrease the risk of algal blooms and fish kills, at least in the short term. However, the generality of biomanipulation effects on water quality across lake types and geographical regions is not known. Therefore, we have undertaken a systematic review of such effects in eutrophic lakes in temperate regions throughout the world.

    Methods

    Searches for literature were made using online publication databases, search engines, specialist websites and bibliographies of literature reviews. Search terms were developed in English, Danish, Dutch and Swedish. Identified articles were screened for relevance using inclusion criteria set out in an a priori protocol. To reduce the risk of bias, we then critically appraised the combined evidence found on each biomanipulation. Data were extracted on outcomes such as Secchi depth and chlorophyll a concentration before, during and/or after manipulation, and on effect modifiers such as lake properties and amounts of fish removed or stocked.

    Results

    Our searches identified more than 14,500 articles. After screening for relevance, 233 of them remained. After exclusions based on critical appraisal, our evidence base included useful data on 128 biomanipulations in 123 lakes. Of these interventions, 85% had been made in Europe and 15% in North America. Meta-analysis showed that removal of planktivores and benthivores (with or without piscivore stocking) leads to increased Secchi depth and decreased chlorophyll a concentration during intervention and the first three years afterwards. Piscivore stocking alone has no significant effect. The response of chlorophyll a levels to biomanipulation is stronger in lakes where fish removal is intense, and in lakes which are small and/or have high pre-manipulation concentrations of total phosphorus.

    Conclusions

    Our review improves on previous reviews of biomanipulation in that we identified a large number of case studies from many parts of the world and used a consistent, repeatable process to screen them for relevance and susceptibility to bias. Our results indicate that removal of planktivorous and benthivorous fish is a useful means of improving water quality in eutrophic lakes. Biomanipulation tends to be particularly successful in relatively small lakes with short retention times and high phosphorus levels. More thorough fish removal increases the efficacy of biomanipulation. Nonetheless successes and failures have occurred across a wide range of conditions.

  • 57.
    Bertos-Fortis, Mireia
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Baltic Sea phytoplankton in a changing environment2016Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Future climate scenarios in the Baltic Sea project increasing sea surface temperature, as well as increasing precipitation and river runoff resulting in decreased salinity. These changes can severely impact the dynamics and function of brackish water communities, specifically phytoplankton. Phytoplankton are a significant source of organic matter to other trophic levels, and some species can be toxic. Their response to future climate conditions is of great relevance for the health of humans and aquatic ecosystems. The aim of this thesis was to assess the potential for climate-induced changes, such as decreasing salinity, to affect phytoplankton dynamics, physiology and chemical profiles in the Baltic Sea.

         Phytoplankton successional patterns in the Baltic Proper consist of a spring bloom where diatoms and dinoflagellates co-occur and a summer bloom dominated by filamentous/colonial cyanobacteria. The consensus is that future warmer conditions will promote filamentous/colonial cyanobacteria blooms. This thesis shows that phytoplankton biomass in the spring bloom was lower in years with milder winters compared with cold winters. This suggests that in terms of annual carbon export to higher trophic levels, loss of biomass from the spring bloom is unlikely to be compensated by summer cyanobacteria. High frequency sampling of phytoplankton performed in this thesis revealed a strong relationship between the dynamics of pico- and filamentous cyanobacteria. Large genetic diversity was found in cyanobacterial populations with high niche differentiation among the same species. At community level, high temperature and low salinity were the main factors shaping the summer cyanobacterial composition. These conditions may promote the predominance of opportunistic filamentous cyanobacteria, e.g. Nodularia spumigena. This species produces various bioactive compounds, including non-ribosomal peptides such as the hepatotoxin nodularin. In this work, N. spumigena subpopulations evolved different physiological strategies, including chemical profiles, to cope with salinity stress. This high phenotypic plasticity ensures survival in future climate conditions. Under salinity stress, some subpopulations displayed shorter filaments as a trade-off. This indicates that the future freshening of the Baltic Sea may promote grazing on filamentous cyanobacteria and modify carbon flows in the ecosystem. In this thesis, Baltic N. spumigena chemotypes and genotypes grouped into two main clusters without influence of geographical origin. Thus, chemical profiling can be used to explore conspecific diversity in closely genetically related N. spumigena subpopulations.

         Overall, this thesis has significantly expanded the knowledge on phytoplankton community and population responses to short- and long-term environmental changes, relevant to project the impacts of future climate conditions in the Baltic Sea.

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    Mireia Bertos-Fortis, Doctoral Thesis (Kappa)
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  • 58.
    Bertos-Fortis, Mireia
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Farnelid, Hanna
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Lindh, Markus V.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Casini, Michele
    Swedish University of Agricultural Sciences.
    Andersson, Agneta
    Umeå University.
    Pinhassi, Jarone
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Legrand, Catherine
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Unscrambling Cyanobacteria Community Dynamics Related to Environmental Factors2016Ingår i: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 7, artikel-id 625Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Future climate scenarios in the Baltic Sea project an increase of cyanobacterial bloom frequency and duration, attributed to eutrophication and climate change. Some cyanobacteria can be toxic and their impact on ecosystem services is relevant for a sustainable sea. Yet, there is limited understanding of the mechanisms regulating cyanobacterial diversity and biogeography. Here we unravel successional patterns and changes in cyanobacterial community structure using a 2-year monthly time series during the productive season in a 100 km coastal-offshore transect using microscopy and high-throughput sequencing of 16S rRNA gene fragments. A total of 565 cyanobacterial OTUs were found, of which 231 where filamentous/colonial and 334 picocyanobacterial. Spatial differences in community structure between coastal and offshore waters were minor. An "epidemic population structure" (dominance of a single cluster) was found for Aphanizomenon/Dolichospermum within the filamentous/colonial cyanobacterial community. In summer, this cluster simultaneously occurred with opportunistic clusters/OTUs, e.g., Nodulana spumigena and Pseudanabaena. Picocyanobacteria, Synechococcus/Cyanobium, formed a consistent but highly diverse group. Overall, the potential drivers structuring summer cyanobacterial communities were temperature and salinity. However, the different responses to environmental factors among and within genera suggest high niche specificity for individual OTUs. The recruitment and occurrence of potentially toxic filamentous/colonial clusters was likely related to disturbance such as mixing events and short-term shifts in salinity, and not solely dependent on increasing temperature and nitrogen-limiting conditions. Nutrients did not explain further the changes in cyanobacterial community composition. Novel occurrence patterns were identified as a strong seasonal succession revealing a tight coupling between the emergence of opportunistic picocyanobacteria and the bloom of filamentous/colonial clusters. These findings highlight that if environmental conditions can partially explain the presence of opportunistic picocyanobacteria, microbial and trophic interactions with filamentous/colonial cyanobacteria should also be considered as potential shaping factors for single-celled communities. Regional climate change scenarios in the Baltic Sea predict environmental shifts leading to higher temperature and lower salinity; conditions identified here as favorable for opportunistic filamentous/colonial cyanobacteria. Altogether, the diversity and complexity of cyanobacterial communities reported here is far greater than previously known, emphasizing the importance of microbial interactions between filamentous and picocyanobacteria in the context of environmental disturbances.

  • 59.
    Betzholtz, Per-Eric
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Forsman, Anders
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Franzén, Markus
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Inter-individual variation in colour patterns in noctuid moths characterizes long-distance dispersers and agricultural pests2019Ingår i: Journal of applied entomology, ISSN 0931-2048, E-ISSN 1439-0418, Vol. 143, nr 9, s. 992-999Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A high capacity for long‐distance dispersal is a key to success for species confronted with environmental heterogeneity, habitat modification, fragmentation and loss. However, dispersal capacity is difficult to quantify and therefore poorly known in most taxa. Here, we report on a test for an association of variation in dispersal capacity with variable colouration of noctuid moths. First, using data from 12 experienced lepidopterologists, we showed that despite variation among experts in average assessments, different species are consistently classified as having non‐variable, variable or highly variable colour patterns when assessed by different experts. We then compared the incidence of non‐resident species with high inter‐individual variation in colour patterns recorded on the isolated island Utklippan (n = 47), with that in a species pool of potential long‐distance dispersers from the nearest mainland (n = 295). Species with high inter‐individual colour pattern variation were over‐represented on the island compared with species having non‐variable colouration. This finding constitutes rare evidence from the wild of long‐distance dispersal, measured on a spatial scale relevant for moths when tracking habitats in fragmented and changing landscapes or when keeping pace with environmental challenges associated with climate change. Finally, we showed that Swedish noctuid moths classified as agricultural pests (n = 28) had more variable colour patterns compared with non‐pests (n = 368). The majority of agricultural pests were also recorded on the isolated island, an outcome that is indicative of pest species having high dispersal capacity. Data on colour pattern variation may thus offer a simple and cost‐effective proxy to estimate dispersal capacity and can also help identify potential pest species. Our findings are potentially useful when modelling and predicting population and range dynamics of species in spatiotemporally heterogeneous environments, with direct implications for conservation biology and pest management.

  • 60.
    Betzholtz, Per-Eric
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Franzén, Markus
    Department of Community Ecology, UFZ Centre for Environmental Research, Halle, Germany.
    Mobility is related to species traits in noctuid moths2011Ingår i: Ecological Entomology, ISSN 0307-6946, E-ISSN 1365-2311, Vol. 36, s. 369-376Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Abstract. 1. Mobility is important for the understanding of how species survive infragmented landscapes and cope with increasing rates of habitat and climate change.However, mobility is a difficult trait to explore and is poorly known in most taxa.Species traits have been studied in relation to range shifts, extinction risks, andresponses to habitat area and isolation, and have also been suggested as good estimatorsof mobility. Here we explore the relation between mobility and species traits in noctuidmoths.2. We sampled noctuid moths by an automatic light-trap on an island far out in theBaltic Sea. We compared traits of the non-resident species on the island with traits ofa species pool of assumed potential migrants from the Swedish mainland.3. Mobility was significantly related to adult activity period, length of flightperiod, and the interaction between host-plant specificity and distribution area. Widelydistributed host-plant generalists were more mobile than host-plant specialists withmore restricted distribution, and species with an adult activity period in August toSeptember moved to the island to a higher extent than species with an adult activityperiod in May to July. Our results remained qualitatively robust in additional analyses,after controlling for phylogeny and including all species recorded on the island, exceptfor the trait ‘length of flight period’.4. Our results highlight the importance of the relation between mobility and speciestraits. Noctuid moths with certain traits move over longer distances than earlier known.This finding is important to include when predicting range dynamics in fragmentedand changing landscapes, and when conservation measures of species are devised.

  • 61.
    Betzholtz, Per-Eric
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Franzén, Markus
    Helmholtz Centre for Environmental Research, Germany.
    Forsman, Anders
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Colour pattern variation can inform about extinction risk in moths2017Ingår i: Animal Conservation, ISSN 1367-9430, E-ISSN 1469-1795, Vol. 20, nr 1, s. 72-79Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Theory posits that species with inter-individual variation in colour patterns should beless vulnerable to extinction, compared with species that do not vary in colour. Toevaluate this prediction, we explored whether differences in colour pattern diversitywas associated with extinction risk, using red-list status for more than 350 species ofnoctuid moths in Sweden. We also evaluated six other species characteristics thathave been proposed to influence extinction risk namely: host plant niche breadth,habitat type, area of occupancy, body size, overwintering life-history stage and lengthof flight activity period. We found that species with variable colour patterns hadreduced extinction risk overall compared with species having non-variable colourpatterns, and that this difference was pronounced more strongly among species havingsmaller areas of occupancy. There were also significant associations with hostplant niche breadth and habitat type, extinction risk being lower on average in polyphagousspecies and in generalist species that occupied different habitat types. Thesefindings represent the first evidence for insects that variable colouration is associatedwith reduced extinction risks. Information on colour pattern variation is readily availablefor many taxa and may be used as a cost-effective proxy for endangerment inthe work of halting national and global biodiversity loss.

  • 62. Bjelke, Ulf
    et al.
    Bohman, Irene
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Herrmann, Jan
    Temporal niches of shredders in lake littorals with possible implications on ecosystem functioning2005Ingår i: Aquatic Ecology, ISSN 1386-2588, Vol. 39, nr 1, s. 41-53Artikel i tidskrift (Refereegranskat)
  • 63.
    Black, Jeffrey M.
    et al.
    Humboldt State University, USA.
    Prop, Jouke
    Larsson, Kjell
    Gotland University, Sweden.
    Wild goose dilemmas: Population consequences of individual decisions in Barnacle geese2007Bok (Övrigt vetenskapligt)
  • 64. Black, Jeffrey
    et al.
    Prop, Jouke
    Larsson, Kjell
    Linnéuniversitetet, Fakulteten för teknik (FTK), Sjöfartshögskolan (SJÖ).
    The Barnacle Goose2014Bok (Refereegranskat)
  • 65. Bohman, B
    et al.
    Nordlander, G
    Nordenhem, H
    Sunnerheim, K
    Borg-Karlson, A-K
    Unelius, Rikard
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Structure - activity relationships of phenyl propanoids as antifeedants for the pine weevil Hylobius abieist2008Ingår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 34, nr 3, s. 339-352Artikel i tidskrift (Refereegranskat)
  • 66.
    Bohman, Björn
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Troger, A.
    University of Hamburg.
    Franke, S.
    University of Hamburg.
    Lorenzo, M. G.
    Fiocruz, Belo Horizonte, Brazil.
    Francke, W.
    University of Hamburg.
    Unelius, C. Rikard
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Structure Elucidation and Synthesis of Dioxolanes Emitted by Two Triatoma Species (Hemiptera Reduviidae)2011Ingår i: Journal of natural products (Print), ISSN 0163-3864, E-ISSN 1520-6025, Vol. 74, nr 4, s. 690-694Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Volatiles from the metastemal glands of two species Of true bugs of the Triatominae subfamily, Triatoma brasiliensis and Triatoma infestans, Were analyzed by SPME-GC/MS. Two sets of new natural products were found: (4S,5S)- and (4R,SR)-2,2,4-triethyl-5-methyl-1,3-dioxolane (1) (major component) and (45*,5S*)-2,4-diethyl-2,S-dimethyl-1,3-dioxolane (2) (trace component),-,(2R/S,4S,SS)- as well as (2R/S,4R,5R)-4-ethyl-5-methyl-2-(1-methylethyl)-1,3-dioxolane (3) (minor component), (2R/S,4S*,5S*).-4-ethyl-5-methyl-2-(1-methylpropyl)-1,3-dioxolane (4), (trace component), and (2R/S,4S*,5S*)-4-ethyl-5-methyl-2-(2-methylpropyl)-1,3-dioxolane (5) (trace component). Syntheses of optically active 1 and 3 were carried out by reacting pure,enantiomers of 2,3-pentanediol with 3-pentanone or 2-methylpropanal. The preparation of, pure 1 stereoisomers of 2,3-pentanediol involved a novel key step for the synthesis of secondary alcohols: the reduction of a carboxylic ester by means of DIBAH and in situ alkylation of the intermediate by Grignard reaction at low temperature Starting from the pure enantiomers of methyl lactate; all four stereoisoniers of 2,3-pentanediol were synthesized. and transformed, to the corresponding isomers of 1 and 2. Relative configurations of the natural products and enantiomeric compositions of naturally occurring 1 and :2 were determined by comparison of their mass spectra and gas chromatographic retention times (co-injection) I with those of authentic reference samples.

  • 67.
    Bohman, Björn
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Unelius, C. Rikard
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Synthesis of all four stereoisomers of 5-hydroxy-4-methyl-3-heptanone using plants and oyster mushrooms2009Ingår i: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 65, nr 42, s. 8697-8701Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    All four possible stereoisomers of 5-hydroxy-4-methyl-3-heptanone were synthesized from common achiral reagents using fast, straightforward organic synthesis, including the use of whole tissue of Daucus carota, Solanum melongena, and Pleurotus ostreatus.

  • 68.
    Bohman, Irene
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Coarse detritus in oligotrophic lake littoral zones: utilization by intervertebrates and contribution to carbon flow2005Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Syftet med denna avhandling är att öka förståelsen av hur grovt organiskt material, sk grovdetritus, tex löv och makrofytrester, bryts ner i sjöars strandzoner. Motivet bakom intresset för detta är att små näringsfattiga sjöar i skogsrika områden ofta är beroende av tillförsel av energi utifrån och att nedbrytningen av grovdetritus är relativt lite undersökt i sjöar. Utifrån tillförd detritus, i löst och partikulär form kan utgöra extra energikälla för sjöekosystem, men bara om några organismer kan tillgodogöra sig detta organiska material. I sötvatten kan sådana organismer vara bakterier, svampar och ryggradslösa djur. Under nedbrytningsförloppet produceras en mängd mellanprodukter som kan användas av andra konsumenter tex fisk. På så sätt återcirkuleras energi och näring från detritus utan fullständig nedbrytning. Vidare har det föreslagits att hög biodiversitet kan resultera i hög ekosystemfunktion, t ex effektiv nedbryning. Därför kan studier av både samhällen och enskilda arter av nedbrytare öka förståelsen av förändringar i hela ekosystemets funktion.

    Inom ramen för avhandlingen har jag studerat vilka arter som deltar i nedbrytningen av grovdetritus och vilka möjliga vägar för det fortsatta nyttjandet av detta material som finns. Jag har särskilt betonat det säsongsmässiga mönstret för omsättningen av grovdetritus och för tillgängligheten av mellanprodukter.

    Resultaten visar att både mikroorganismer och ryggradslösa djur successivt processar tillgängligt grovt organiskt material under hela året. Viktminskningsmönstret över året hos löv och makrofytrester är nära kopplat till förekomst och tillväxt hos olika arter av nedbrytande ryggradslösa djur, sk fragmenterare. Av de vanligaste förekommande tio arterna fragmenterare, var nio nattsländelarver. Därför drar jag slutsatsen att dessa arter av nattsländelarver spelar en avgörande roll för omsättningen av grovdetritus i sjöstränder i sydöstra Sverige. Samtidigt visar resultaten att sötvattengråsuggan spelar mindre roll för nedbrytningen av grovdetritus än förväntat. Denna art föredrar andra födoämnen åtminstone under våren och undviker de grunda bottnarna där grovdetritus finns under vintern. I laboratorieexperiment har jag visat att nedbrytning av löv i närvaro av fragmenterare huvudsakligen ger upphov till två olika produkter: löst organiskt material och finpartikulära rester. Därmed har jag visat att fragmenterare kan omsätta grovdetritus snabbare än mikroorganismer. Slutsatsen blir att mikroorganismernas kvantitativa bidrag till nedbrytning av grov grovdetritus är beroende av mängden fragmenterare. Jag har också visat att olika kombinationer detritussorter och fragmenterararter kan påverka när olika nedbryningsprodukter blir tillgängliga för andra organismer.

    Sammanfatningsvis har jag visat att grovdetritus är en attraktiv födoresurs för ryggradslösa djur i näringsfattiga sjöars strandzoner, precis som i små bäckar. Dessutom visar jag att de arter av fragmenterare som är speciella för sjöar, tillsammans omsätter tillgängligt grovdetritus i ett finskaligt tidsmönster över året. Detta mönster har utvecklats genom anpassning till trädens lövfällning och nedvissningen av vattenväxter som sker på hösten i vårt klimat. Jag vill också betona att ökade kunskaper om nedbrytning av grovdetritus krävs för att kunna förutsäga effekter av olika störningar i dessa ekosystem. Slutligen rekommenderar jag att nedbrytningshastigheten för grovdetritus testas som mått på ekosystemfunktion också i sjöar.

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  • 69.
    Bohman, Irene
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bjelke, Ulf
    Seasonal variation of food sources in lake littoral benthic fauna, as indicated by stable isotopesManuskript (preprint) (Övrigt vetenskapligt)
  • 70.
    Bohman, Irene
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Herrmann, Jan
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    The timing for winter-growing shredder species and leaf litter turnover rate in an oligotrophic lake, SE Sweden2006Ingår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 556, nr 1, s. 99-108Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Small freshwater systems often depend on allochthonous organic subsidies to sustain productivity. Benthic invertebrates consuming coarse detritus maintain the energy flow by conveying dead organic matter into prey items and increase the food availability for other consumers. Compared to lotic systems, the dynamics of coarse detritus decomposition has not received much attention in lakes. The objectives of this study were to investigate the seasonality of leaf litter turnover and the timing of abundance of potential shredder species in a typical oligotrophic boreal lake. Leaf litter was experimentally exposed in litterbags in the littoral zone in Lake Välen from autumn to late spring two consecutive years. The weight loss rate of leaf litter initially followed the same pattern during both winter periods, but was markedly influenced by freezing in late winter the second year. Further, the seasonal variation patterns in abundance in litterbags were quite different among the potential shredder species. Only the limnephilid caddis larvae showed a density variation pattern possible to connect to the weight loss of leaf litter in litterbags. Otherwise frequent detritivores such as Asellus aquaticus and Leptophlebia marginata displayed lowest density in litterbags during the main weight loss period. However, after the long ice period the second winter the remaining leaf litter seemed to be consumed by A. aquaticus. With increasing knowledge of the initial leaf breakdown process and the guild of shredders in lakes, the decomposition rate may also in this habitat become a useful instrument when evaluating the impact from perturbations on ecosystem function.

  • 71.
    Bohman, Irene
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Tranvik, Lars
    The effects of shredding invertebrates on the transfer of organic carbon from littoral leaf litter to water-column bacteria2001Ingår i: Aquatic Ecology, ISSN 1386-2588, Vol. 35, nr 1, s. 43-50Artikel i tidskrift (Refereegranskat)
  • 72.
    Bonnedahl, Jonas
    et al.
    Uppsala University ; Kalmar County Hospital.
    Drobni, P.
    Cent Hosp Växjö.
    Johansson, A.
    Umeå University.
    Hernandez, Jorge
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV. Uppsala University.
    Melhus, A.
    Uppsala University.
    Stedt, Johan
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Olsen, Björn
    Uppsala University.
    Drobni, M.
    Uppsala University.
    Characterization, and comparison, of human clinical and black-headed gull (Larus ridibundus) extended-spectrum beta-lactamase-producing bacterial isolates from Kalmar, on the southeast coast of Sweden2010Ingår i: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 65, nr 9, s. 1939-1944Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Antibiotic resistance is one of the great challenges for modern healthcare. In Gram-negative bacteria, CTX-M-type extended-spectrum beta-lactamases (ESBLs) have been rapidly spreading through Europe since the early 2000s. In Sweden, ESBL-producing Escherichia coli are still rare, but a 3-fold increase has been seen from 2004 to 2007. Enterobacteria and normal flora of wild animals, with or without antibiotic resistance traits, constitute a potential source of human infection and colonization. We studied wild birds with the aim to understand the environmental dissemination of antibiotic resistance and, focusing on clinically relevant resistance types, we made comparisons with human clinical samples. In this study, ESBL-producing human clinical isolates and isolates from juvenile black-headed gulls from Kalmar County hospital and the city of Kalmar, respectively, on the southeast coast of Sweden, were characterized and compared. Despite a low frequency of antibiotic resistance among the isolates from gulls, ESBL-producing E. coli isolates were found, two with bla(CTX-M-14) and one with bla(CTX-M-15). The same CTX-M types were dominant among human ESBL isolates. In addition, gull isolates were dispersed among the human samples in the PhenePlate (TM) clustering system, indicating that they neither differ from the human isolates nor form any separate clonal clustering. The finding of CTX-M-type ESBLs in E. coli isolated from black-headed gulls in Sweden, where 'background resistance' is low, is consistent with an ongoing environmental spread of these plasmid-borne resistance genes. The results indicate that a potential for transfer between the human population and environment exists even in countries with a low level of antibiotic resistance.

  • 73. Boras, Julia
    et al.
    Sala, Montse M.
    Baltar, Federico
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Arístegui, Javier
    Duarte, Carlos M.
    Vaqué, D.
    Effect of viruses and protists on bacteria in eddies of the Canary Current region (subtropical Northeast Atlantic).2010Ingår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 55, nr 2, s. 885-898Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effect of oceanic eddies on microbial processes, with emphasis on bacterial losses due to protists and phages, was examined in the Canary Current region (subtropical northeast Atlantic) through the water column (down to 1000 m) during August 2006. Sampling stations were located in cyclonic and anticyclonic eddies, as well as in regions situated outside the influence of the eddy field (far-field stations). In the euphotic zone, in cyclonic eddies losses of bacteria due to viruses and protists were from 25.6% to 69.8%, and from not detected to 46.8% of bacterial production (BP) d(-1), respectively. In anticyclonic eddies, these values ranged from 20.6% to 90.2% of BP d(-1) for viruses, and from 8.0% to 79.4% of BP d(-1) for protists. At far-field stations, losses of bacteria ranged from 48.7% to 66.9% for viruses, and from not detected to 44.8% for protists. In addition, covering all stations and depths (from the epipelagic to the bathypelagic layer), bacterial losses due to viruses were significantly higher than losses by protists, and did not differ significantly among depths except for the stations situated in anticyclonic eddies, where they were significantly higher in the epipelagic layer. Lysogenic infection was more frequent at anticyclonic stations, where the highest pressure of protists on bacteria was observed. Because of the importance of viral activity, we suggest that lysis products from bacteria may be a source of regenerated nutrients in the surface of the oligotrophic ocean, in addition to the input of nutrients upwelled by eddies.

  • 74. Bowers, HA
    et al.
    Brutemark, Andreas
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    F de Carvalho, Wanderson
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Granéli, Edna
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Combining flow cytometry and real-time PCR methodology to demonstrate consumption in Prymnesium parvum2010Ingår i: Journal of the American Water Resources Association, ISSN 1093-474X, E-ISSN 1752-1688, Vol. 46, s. 133-143Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Harmful algal bloom species can persist in the environment, impacting aquatic life and human health. One of the mechanisms by which some harmful algal bloom species are able to persist is by consumption of organic particles. Methods to demonstrate and measure consumption can yield insight into how populations thrive. Here, we combine flow cytometry and real-time PCR to demonstrate consumption of a cryptophyte species (Rhodomonas sp.) by a toxic mixotrophic haptophyte (Prymnesium parvum). Using flow cytometry, the feeding frequency of a population of P. parvum cells was calculated using the phycoerythrin (PE) fluorescence signal from Rhodomonas sp. and the fluorescence of an acidotropic probe labeling the food vacuoles. Feeding frequency increased in the beginning of the experiment and then began to decline, reaching a maximum of 47.5% of the whole P. parvum population after 212 min. The maximum number of consumed Rhodomonas sp. cells was 0.8 per P. parvum cell, and occurred after 114 min corresponding to an ingestion rate of 0.4 Rhodomonas sp. cells/P. parvum/h. Cells from the feeding P. parvum population were sorted, washed, and subjected to a real-time PCR assay targeting the cryptophyte 18S locus. There was a correlation between cycle threshold (Ct) values and number of consumed prey cells calculated by fluorescence. Overall, this study shows that flow cytometric analysis, of the acidotropic probe and prey pigments, is an efficient and rapid tool in enumerating food vacuoles and the number of prey cells consumed. Furthermore, we suggest that real-time PCR can be applied to cells sorted by flow cytometry, thus allowing for the detection and potential quantification of the targeted prey cells.

  • 75.
    Brindefalk, Bjorn
    et al.
    Stockholm University.
    Ekman, Martin
    Stockholm University.
    Ininbergs, Karolina
    Stockholm University.
    Dupont, Christopher L.
    J Craig Venter Inst, USA.
    Yooseph, Shibu
    J Craig Venter Inst, USA.
    Pinhassi, Jarone
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Bergman, Birgitta
    Stockholm University.
    Distribution and expression of microbial rhodopsins in the Baltic Sea and adjacent waters2016Ingår i: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 18, nr 12, s. 4442-4455Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Rhodopsins are light-driven ion-pumping membrane proteins found in many organisms and are proposed to be of global importance for oceanic microbial energy generation. Several studies have focused on marine environments, with less exploration of rhodopsins in brackish waters. We investigated microbial rhodopsins in the Baltic Sea using size-fractionated metagenomic and metatranscriptomic datasets collected along a salinity gradient spanning from similar to 0 to 35 PSU. The normalised genomic abundance of rhodopsins in Bacteria, as well as rhodopsin gene expression, was highest in the smallest size fraction (0.1-0.8 mu m), relative to the medium (0.8-3.0 mu m) and large (> 3.0 mu m) size fractions. The abundance of rhodopsins in the two smaller size fractions displayed a positive correlation with salinity. Proteobacteria and Bacteroidetes rhodopsins were the most abundant while Actinobacteria rhodopsins, or actinorhodopsins, were common at lower salinities. Phylogenetic analysis indicated that rhodopsins have adapted independently to the marine-brackish transition on multiple occasions, giving rise to green light-adapted variants from ancestral blue light-adapted ones. A notable diversity of viral-like rhodopsins was also detected in the dataset and potentially linked with eukaryotic phytoplankton blooms. Finally, a new clade of likely proton-pumping rhodopsin with non-canonical amino acids in the spectral tuning and proton accepting site was identified.

  • 76.
    Broman, Elias
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Ecology and evolution of coastal Baltic Sea 'dead zone' sediments2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Arealerna av 'döda bottnar' i Östersjön har ökat som en följd av industrialiseringen och användandet av gödningsmedel. Föroreningen av Östersjöns kust och öppna vatten med näringsämnen leder till en ökad tillväxt av algblomningar. En del av dessa alger sjunker till havsbotten och orsakar att så kallad hypoxia utvecklas. Den naturliga stratifieringen av vattenkolummen avgränsar yt- och bottenvattnet vilket leder till att bottenzonen är speciellt utsatt för syrebrist. Detta eftersom mikroorganismer i bottensedimentet använder syre och organiskt material för att leva. Hypoxia (<2 mg/L O2) och anoxia (inget syre) är dödligt för de flesta organismer och endast specialiserade organismer (vanligtvis vissa mikroorganismer) kan överleva. Det är av denna anledning dessa bottenzoner ofta kallas för 'döda bottnar'. Målet med denna avhandling var att undersöka förändringar i de mikrobiologiska samhällena vid nedbrytning av organiskt algmaterial, och undersöka vilken effekt syresättning har på ekologin i döda bottensediment i Östersjöns kust. I mer detalj studerades kemiska flöden, växt- och djurplankton, samt mikrobiologiska samhällen och deras metaboliska processer. Resultaten från fältprovtagningar och inkubationer i laboratoriet visade att nedbrytning av algmaterial i syrerikt sediment till viss del gynnade arkéer; syretillsättning av anoxiska sediment minskade det lagrade organiska materialet och ledde till ökad kläckning av djurplanktonägg; vilande kiselalger begravda i hypoxisk/anoxisk sediment var levande och vaknade vid tillförsel av ljus snarare än syre. Förändringar i mikrobiologiska samhällen vid syreförändringar var beroende av historisk exponering av syre i sedimentytan. Det observerades också att mikroorganismer anpassade till episodiska förändringar i syre gynnades. Fakultativt anaerobiska svavel/sulfidoxiderande bakteriesläkten gynnades efter syresättning av hypoxisk/anoxiskt sediment och gener involverade i omvandling av svavelämnen och kvävefixering var vanliga. Slutligen visade resultaten att syresättning reglerar metaboliska processer involverade i kretsloppen för svavel och metan. Speciellt genom processer som leder till en minskning av den gifta gasen svavelväte och växthusgasen metan. Denna avhandling har undersökt hur döda bottensediment förändras och utvecklas vid skiftande syreförhållanden och visar att syresättning av 'döda bottnar' kan skapa gynnsamma förhållanden i sedimentytan för återetablering av mikro- och makroorganismsamhällen. 

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  • 77.
    Broman, Elias
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Brüsin, Martin
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Dopson, Mark
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Hylander, Samuel
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Oxygenation of anoxic sediments triggers hatching of zooplankton eggs2015Ingår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 282, nr 1817, artikel-id 20152025Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Many coastal marine systems have extensive areas with anoxic sediments and it is not well known how these conditions affect the benthic-pelagic coupling. Zooplankton lay their eggs in the pelagic zone, and some sink and lie dormant in the sediment, before hatched zooplankton return to the water column. In this study, we investigated how oxygenation of long-term anoxic sediments affects the hatching frequency of dormant zooplankton eggs. Anoxic sediments from the brackish Baltic Sea were sampled and incubated for 26 days with constant aeration whereby, the sediment surface and the overlying water were turned oxic. Newly hatched rotifers and copepod nauplii (juveniles) were observed after 5 and 8 days, respectively. Approximately 1.5 × 105 nauplii per m-2 emerged from sediment turned oxic compared to 0.02 × 105 m-2 from controls maintained anoxic. This study demonstrated that re-oxygenation of anoxic sediments activated a large pool of buried zooplankton eggs, strengthening the benthic-pelagic coupling of the system. Modelling of the studied anoxic zone suggested that a substantial part of the pelagic copepod population can derive from hatching of dormant eggs. We suggest that this process should be included in future studies to understand population dynamics and carbon flows in marine pelagic systems.

  • 78.
    Broman, Elias
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Li, Lingni
    Fridlund, Jimmy
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Svensson, Fredrik
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Legrand, Catherine
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Dopson, Mark
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Eutrophication induced early stage hypoxic ‘dead zone’ sediment releases nitrate and stimulates growth of archaeaManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    In the Baltic Sea, two annual algal blooms occur in spring and summer. The bloom intensity is determined by nutrient concentrations in the water column, while the period depends on weather conditions. During the course of the bloom, dead cells sink to the sediment where their degradation consumes oxygen to create hypoxic zones (< 2 mg/L dissolved oxygen, referred to as ‘dead zones’). These zones prevent the establishment of benthic communities and result in fish mortality. The aim of the study was to determine how the sediment chemistry and microbial community composition changed due to phytoplankton biomass degradation by adding cyanobacterial or diatom biomass to sediment cores from an all-year round oxic coastal Baltic Sea bay. After biomass addition, some typical anaerobic microbial processes were observed such as a decrease in NO2-+NO3- in the sediment surface (0-1 cm) and iron in the underlying layer (1-2 cm). In addition, an increase in NO2-+NO3- was observed in the water phase in all incubations (including controls without addition of phytoplankton biomass). The combination of NO2-+NO3- diffusion from the sediment plus nitrification of the available NH4+ could not account for this increase. Potential nitrogen sources that could at least partially explain this discrepancy included microbial nitrogen fixation and cycling of nitrogen compounds from deeper layers of the sediment. Based on 16S rRNA gene sequences, the addition of diatom biomass caused minor changes in the relative abundance of microbial community members while cyanobacterial biomass caused a large increase in ferrous iron-oxidizing archaea. Considering that OTUs sharing lineages with acidophilic microorganisms were present, it was suggested that specific niches developed in sediment microenvironments. These findings highlight the importance of nitrogen cycling in oxic sediments and early microbial community changes in the sediment surface due to sinking phytoplankton before major hypoxia events occur. The release of nitrate into the water could potentially enhance algal blooms and facilitate the development of ‘dead zones’.

  • 79.
    Broman, Elias
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Li, Lingni
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Fridlund, Jimmy
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Svensson, Fredrik
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Legrand, Catherine
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Dopson, Mark
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Spring and Late Summer Phytoplankton Biomass Impact on the Coastal Sediment Microbial Community Structure2019Ingår i: Microbial Ecology, ISSN 0095-3628, E-ISSN 1432-184X, nr 2, s. 288-303Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Two annual Baltic Sea phytoplankton blooms occur in spring and summer. The bloom intensity is determined by nutrient concentrations in the water, while the period depends on weather conditions. During the course of the bloom, dead cells sink to the sediment where their degradation consumes oxygen to create hypoxic zones (< 2 mg/L dissolved oxygen). These zones prevent the establishment of benthic communities and may result in fish mortality. The aim of the study was to determine how the spring and autumn sediment chemistry and microbial community composition changed due to degradation of diatom or cyanobacterial biomass, respectively. Results from incubation of sediment cores showed some typical anaerobic microbial processes after biomass addition such as a decrease in NO2 + NO3 in the sediment surface (0–1 cm) and iron in the underlying layer (1–2 cm). In addition, an increase in NO2 + NO3 was observed in the overlying benthic water in all amended and control incubations. The combination of NO2 + NO3 diffusion plus nitrification could not account for this increase. Based on 16S rRNA gene sequences, the addition of cyanobacterial biomass during autumn caused a large increase in ferrous iron-oxidizing archaea while diatom biomass amendment during spring caused minor changes in the microbial community. Considering that OTUs sharing lineages with acidophilic microorganisms had a high relative abundance during autumn, it was suggested that specific niches developed in sediment microenvironments. These findings highlight the importance of nitrogen cycling and early microbial community changes in the sediment due to sinking phytoplankton before potential hypoxia occurs.

  • 80.
    Broman, Elias
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Sachpazidou, Varvara
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Dopson, Mark
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Hylander, Samuel
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Diatoms dominate the eukaryotic metatranscriptome during spring in coastal 'dead zone' sediments2017Ingår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 284, nr 1864, artikel-id 20171617Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An important characteristic of marine sediments is the oxygen concentration that affects many central metabolic processes. There has been a widespread increase in hypoxia in coastal systems (referred to as 'dead zones') mainly caused by eutrophication. Hence, it is central to understand the metabolism and ecology of eukaryotic life in sediments during changing oxygen conditions. Therefore, we sampled coastal 'dead zone' Baltic Sea sediment during autumn and spring, and analysed the eukaryotic metatranscriptome from field samples and after incubation in the dark under oxic or anoxic conditions. Bacillariophyta (diatoms) dominated the eukaryotic metatranscriptome in spring and were also abundant during autumn. A large fraction of the diatom RNA reads was associated with the photosystems suggesting a constitutive expression in darkness. Microscope observation showed intact diatom cells and these would, if hatched, represent a significant part of the pelagic phytoplankton biomass. Oxygenation did not significantly change the relative proportion of diatoms nor resulted in any major shifts in metabolic 'signatures'. By contrast, diatoms rapidly responded when exposed to light suggesting that light is limiting diatom development in hypoxic sediments. Hence, it is suggested that diatoms in hypoxic sediments are on 'standby' to exploit the environment if they reach suitable habitats.

  • 81.
    Broman, Elias
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Sachpazidou, Varvara
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Pinhassi, Jarone
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Dopson, Mark
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Oxygenation of Hypoxic Coastal Baltic Sea Sediments Impacts on Chemistry, Microbial Community Composition, and Metabolism2017Ingår i: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 8, artikel-id 2453Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Baltic Sea has undergone severe eutrophication during the last century, resulting in increased algal blooms and the development of hypoxic bottom waters. In this study, we sampled oxygen deficient sediment cores from a Baltic Sea coastal bay and exposed the bottom water including the sediment surface to oxygen shifts via artificial addition of air during laboratory incubation. Surface sediment (top 1 cm) from the replicate cores were sliced in the field as well as throughout the laboratory incubations and chemical parameters were analyzed along with high throughput sequencing of community DNA and RNA. After oxygenation, dissolved iron decreased in the water overlying the sediment while inorganic sulfur compounds (thiosulfate and tetrathionate) increased when the water was kept anoxic. Oxygenation of the sediment also maintained RNA transcripts attributed to sulfide and sulfur oxidation as well as nitrogen fixation in the sediment surface. Based on 16S rRNA gene and metatranscriptomic analyses it was found that oxygenation of the sediment surface caused a bloom of the Epsilonproteobacteria genus Arcobacter. In addition, the formation of a thick white film was observed that was likely filamentous zero-valent sulfur produced by the Arcobacter spp. Based on these results, sulfur cycling and nitrogen fixation that were evident in the field samples were ongoing during re-oxygenation of the sediment. These processes potentially added organic nitrogen to the system and facilitated the re-establishment of micro- and macroorganism communities in the benthic zone.

  • 82.
    Broman, Elias
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Sjöstedt, Johanna
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM). Lund university;Tech Univ Denmark, Denmark.
    Pinhassi, Jarone
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Dopson, Mark
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Shifts in coastal sediment oxygenation cause pronounced changes in microbial community composition and associated metabolism2017Ingår i: Microbiome, ISSN 0026-2633, E-ISSN 2049-2618, Vol. 5, artikel-id 96Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background

    A key characteristic of eutrophication in coastal seas is the expansion of hypoxic bottom waters, often referred to as ‘dead zones’. One proposed remediation strategy for coastal dead zones in the Baltic Sea is to mix the water column using pump stations, circulating oxygenated water to the sea bottom. Although microbial metabolism in the sediment surface is recognized as key in regulating bulk chemical fluxes, it remains unknown how the microbial community and its metabolic processes are influenced by shifts in oxygen availability. Here, coastal Baltic Sea sediments sampled from oxic and anoxic sites, plus an intermediate area subjected to episodic oxygenation, were experimentally exposed to oxygen shifts. Chemical, 16S rRNA gene, metagenomic, and metatranscriptomic analyses were conducted to investigate changes in chemistry fluxes, microbial community structure, and metabolic functions in the sediment surface.

    Results

    Compared to anoxic controls, oxygenation of anoxic sediment resulted in a proliferation of bacterial populations in the facultative anaerobic genus Sulfurovum that are capable of oxidizing toxic sulfide. Furthermore, the oxygenated sediment had higher amounts of RNA transcripts annotated as sqr, fccB, and dsrA involved in sulfide oxidation. In addition, the importance of cryptic sulfur cycling was highlighted by the oxidative genes listed above as well as dsvA, ttrB, dmsA, and ddhAB that encode reductive processes being identified in anoxic and intermediate sediments turned oxic. In particular, the intermediate site sediments responded differently upon oxygenation compared to the anoxic and oxic site sediments. This included a microbial community composition with more habitat generalists, lower amounts of RNA transcripts attributed to methane oxidation, and a reduced rate of organic matter degradation.

    Conclusions

    These novel data emphasize that genetic expression analyses has the power to identify key molecular mechanisms that regulate microbial community responses upon oxygenation of dead zones. Moreover, these results highlight that microbial responses, and therefore ultimately remediation efforts, depend largely on the oxygenation history of sites. Furthermore, it was shown that re-oxygenation efforts to remediate dead zones could ultimately be facilitated by in situ microbial molecular mechanisms involved in removal of toxic H2S and the potent greenhouse gas methane.

  • 83.
    Brown, Robert L.
    et al.
    The New Zealand Institute for Plant & Food Research Ltd, New Zealand ; University of Auckland, New Zealand.
    El-Sayed, Ashraf M
    The New Zealand Institute for Plant & Food Research Ltd, New Zealand.
    Unelius, C. Rikard
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). The New Zealand Institute for Plant & Food Research Ltd, New Zealand.
    Beggs, Jacqueline R
    University of Auckland, New Zealand.
    Suckling, David M
    The New Zealand Institute for Plant & Food Research Ltd, New Zealand ; University of Auckland, New Zealand.
    Invasive Vespula Wasps Utilize Kairomones to Exploit Honeydew Produced by Sooty Scale Insects, Ultracoelostoma.2015Ingår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 41, nr 11, s. 1018-1027Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Vespula wasps are widely distributed invasive alien species that are able to reach high population densities in the 1.2 M ha of beech forests (Fuscospora spp.) of New Zealand's South Island. These endemic temperate forests have an abundance of carbohydrate-rich honeydew produced by native scale insects (Ultracoelostoma spp.). A characteristic aroma is associated with the honeydew in beech forests, which we hypothesized is the signal used by wasps to harvest the vast resources previously exploited by birds and other insects. Volatile collections were taken of black beech tree trunks with honeydew and sooty mold present, and analyzed with a gas chromatograph-mass spectrometer. Eleven compounds (benzaldehyde, benzyl alcohol, 2-phenylethyl acetate, 2-phenylethanol, phenylacetaldehyde, methyl 2-phenylacetate, ethyl 2-phenylacetate, methyl salicylate, n-octanol, octan-3-ol, and 1-octen-3-ol) were positively identified from the headspace, and were shown to elicit an electrophysiological response from Vespula vulgaris worker antennae by using electroantennography (EAG). Field trials with delta traps individually baited with these compounds confirmed wasp attraction to 8 of the 11 compounds tested, with 2-phenylethyl acetate, methyl salicylate, and octan-3-ol capturing the same numbers of wasps as the control. In later trials, attraction to a 1:1 blend of benzaldehyde and n-octanol was significantly higher (45 %) than to any other treatment. Many of the chemicals identified are known to be associated with fermenting sugars, or with fungal aroma. Benzaldehyde and n-octanol are common compounds produced by many different species in nature. The ability to respond to generic signals emanating from sugar resources is likely to contribute to the success of V. vulgaris as an invasive species.

  • 84.
    Brown, Robert L.
    et al.
    New Zealand Inst Plant & Food Res Ltd.
    El-Sayed, Ashraf M.
    New Zealand Inst Plant & Food Res Ltd.
    Unelius, C. Rikard
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB).
    Suckling, David M.
    New Zealand Inst Plant & Food Res Ltd.
    Attraction of the invasive social wasp, Vespula vulgaris, by volatiles from fermented brown sugar2014Ingår i: Entomologia Experimentalis et Applicata, ISSN 0013-8703, E-ISSN 1570-7458, Vol. 151, nr 2, s. 182-190Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The introduction of invasive social wasp species of the genus Vespula (Hymenoptera: Vespidae) to New Zealand has caused a major ecological problem, particularly in the beech forests (Nothofagus spp.) of the South Island, where they have destabilized the native bird and invertebrate biodiversity. New attractants are under investigation as part of a search for pest management solutions. Fermenting brown sugar has been previously reported as a social wasp attractant. This work was undertaken to identify compounds from fermented brown sugar attractive to social wasps. Raw fermented brown sugar was confirmed to be attractive in a field trial and 10 chemical compounds present in the headspace were positively identified by coupled gas chromatography-mass spectrometry and synthetic references. During electroantennogram experiments, 3-methyl-1-butanol, 3-methylbutyl acetate, and ethyl hexanoate elicited high electrophysiological responses from Vespula vulgaris (L.) antennae. These compounds mediated attraction of V.vulgaris wasps in forest margins by trapping. A blend of these compounds could be used as a lure in a monitoring tool, or even a local suppression method if combined with a toxin.

  • 85.
    Brutemark, Andreas
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Granéli, Edna
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Role of mixotrophy and light for growth and survival of the toxic haptophyte Prymnesium parvum2011Ingår i: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 10, s. 388-394Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mixotrophy in Prymnesium parvum was investigated using carbon (δ13C) and nitrogen (δ15N) stable isotopes. The experiment was performed in light and dark. In the dark treatment we expected that the mixotrophic P. parvum would rely solely on its prey and therefore reflect the prey isotopic signatures. In the light treatment P. parvum can perform photosynthesis as well as utilize its prey, thus we expect the isotopic signatures to be between the dark mixed cultures and the monocultures, depending on how much prey was utilized. In the light treatment, addition of the ciliate Myrionecta rubra resulted in higher P. parvum cell numbers compared to monocultures. During the experiment, cell numbers in the dark monocultures and the mixed dark cultures did not increase. P. parvum had 2.5-3 times higher cellular phosphorus and nitrogen content in the dark compared to the cultures in the light whereas no difference in carbon content between treatments could be observed. This suggests that P. parvum can utilize nitrogen and phosphorus but not carbon in the dark. It thus seems as if P. parvum relies on photosynthesis to meet the carbon and energy demand required for growth. The expected isotopic signatures “become what you eat…plus a few per mil” were not observed. In the dark treatment, the δ13C did not differ between monocultures and mixed cultures. In the light treatments P. parvum δ13C became less negative then the corresponding dark treatments indicating that P. parvum used CO2 rather than carbon from the added prey. No difference in δ15N between monocultures and mixed cultures could be observed during the experiment. We argue that light is necessary for P. parvum growth and that the ability to utilize nutrients originating from their prey may be important in bloom formation.

  • 86.
    Brutemark, Andreas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Lindehoff, Elin
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Granéli, Edna
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Granéli, Wilhelm
    Carbon isotope signature variability among cultured microalgae: Influence of species, nutrients and growth2009Ingår i: Journal of Experimental Marine Biology and Ecology, ISSN 0022-0981, E-ISSN 1879-1697, Vol. 372, nr 1-2, s. 98-105Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study we have investigated whether the carbon isotopic signature differs between different groups and species of marine phytoplankton depending on growth phase, nutrient conditions and salinity. The 15 investigated algal species, representing the Bacillariophyceae, Chlorophyceae, Cryptophyceae, Cyanophyceae, Dinophyceae and Haptophyceae classes were grown in batch monocultures and analysed for delta(13)C in both exponential and stationary phase. For all the cultured species, delta(13)C signatures ranged from -23.5 parts per thousand (Imantonia sp.) to - 12.3 parts per thousand (Nodulania spumigena) in the exponential phase and from - 18.8 parts per thousand (Amphidinium carterae) to - 8.0 parts per thousand (Anabaena lemmermannii) in the stationary phase. Three species (Dunaliella tertiolecta, Rhodomonas sp.. Heterocapsa triquetra) were also grown under nutrient sufficient and nitrogen or phosphorus deficient conditions. Nitrogen limitation resulted in a more negative delta(13)C signature, whereas no effect could be observed during phosphorus limitation compared to nutrient sufficient conditions. Growth of Prymnesium parvum in two different salinities resulted in a more negative delta(13)C signature in the 26 parts per thousand-media compared to growth in 7 parts per thousand-media. Our results show that the carbon isotopic signature of phytoplankton may be affected by salinity, differ among different phytoplankton species, between exponential and stationary phase, as well as between nutrient treatments.

  • 87.
    Brüsin, Martin
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Svensson, P. Andreas
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Hylander, Samuel
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Individual changes in zooplankton pigmentation in relation to ultraviolet radiation and predator cues2016Ingår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 61, nr 4, s. 1337-1344Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Copepods are common crustaceans in aquatic systems and one of the most important producers of carotenoidastaxanthin pigments, which can enhance the animals’ resistance against potentially damaging ultraviolet radiation (UVR), but at the same time, increases the risk of fish predation. Previous studies have demonstrated that copepods have different pigmentation levels matching the current threat level in terms of UVR and fish occurrence. However, these other studies have quantified population-levels changes in pigmentation, making it difficult to disentangle the role of individual phenotypic colour changes from that of selection.We quantified carotenoid-based pigmentation with colorimetric methods, which enabled us to track changes within individual copepods. Two species of copepods, Diaptomus castor and Eudiaptomus gracilis, were exposed to high and low UVR and fish cues in a factorial design. L*a*b* colour values (CIE; CommissionInternational de l’Eclairage) were extracted from digital photographs of each copepod and used as proxies for carotenoid concentration. Our results showed that individual copepods significantly changed their pigmentation in response to both UVR and fish cues within a period of 2 weeks. However, the responses differed between sexes and between adults and juveniles. UVR effects were present in all life-stages whereas fish effects were only detected in juveniles, with largest responses in D. castor. This confirms that carotenoid pigmentation is a phenotypically plastic trait, and highlights that strategies for trading off risks of UVR and predation differ between males and females as well as between life-stages.

  • 88.
    Bunse, Carina
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Bertos-Fortis, Mireia
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Sassenhagen, Ingrid
    Lund University.
    Sildever, Sirje
    Tallinn University of Technology, Estonia.
    Sjöqvist, Conny
    Marine Research Centre, Finland;Åbo Akademi University, Finland.
    Godhe, Anna
    University of Gothenburg.
    Gross, Susanna
    University of Gothenburg.
    Kremp, Anke
    Marine Research Centre, Finland.
    Lips, Inga
    Tallinn University of Technology, Estonia.
    Lundholm, Nina
    University of Copenhagen, Denmark.
    Rengefors, Karin
    Lund University.
    Sefbom, Josefin
    University of Gothenburg.
    Pinhassi, Jarone
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Legrand, Catherine
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Spatio-Temporal Interdependence of Bacteria and Phytoplankton during a Baltic Sea Spring Bloom2016Ingår i: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 7, artikel-id 517Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In temperate systems, phytoplankton spring blooms deplete inorganic nutrients and are major sources of organic matter for the microbial loop. In response to phytoplankton exudates and environmental factors, heterotrophic microbial communities are highly dynamic and change their abundance and composition both on spatial and temporal scales. Yet, most of our understanding about these processes comes from laboratory model organism studies, mesocosm experiments or single temporal transects. Spatial -temporal studies examining interactions of phytoplankton blooms and bacterioplankton community composition and function, though being highly informative, are scarce. In this study, pelagic microbial community dynamics (bacteria and phytoplankton) and environmental variables were monitored during a spring bloom across the Baltic Proper (two cruises between North Germany to Gulf of Finland). To test to what extent bacterioplankton community composition relates to the spring bloom, we used next generation amplicon sequencing of the 16S rRNA gene, phytoplankton diversity analysis based on microscopy counts and population genotyping of the dominating diatom Skeletonema rnarinoi. Several phytoplankton bloom related and environmental variables were identified to influence bacterial community composition. Members of Bacteroidetes and Alphaproteobacteria dominated the bacterial community composition but the bacterial groups showed no apparent correlation with direct bloom related variables. The less abundant bacterial phyla Actinobacteria, Planctomycetes, and Verrucomicrobia, on the other hand, were strongly associated with phytoplankton biomass, diatom:dinoflagellate ratio, and colored dissolved organic matter (cDOM). Many bacterial operational taxonomic units (OTUs) showed high niche specificities. For example, particular Bacteroidetes OTUs were associated with two distinct genetic clusters of S. marinoi. Our study revealed the complexity of interactions of bacterial taxa with inter- and intraspecific genetic variation in phytoplankton. Overall, our findings imply that biotic and abiotic factors during spring bloom influence bacterial community dynamics in a hierarchical manner.

  • 89.
    Bunse, Carina
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM). Carl von Ossietzky Univ Oldenburg, Germany.
    Israelsson, Stina
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Baltar, Federico
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM). Univ Vienna, Austria.
    Bertos-Fortis, Mireia
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Fridolfsson, Emil
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Legrand, Catherine
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Lindehoff, Elin
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Lindh, Markus V.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM). Swedish Meteorological & Hydrological Institute.
    Martínez-García, Sandra
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM). Univ Vigo, Spain.
    Pinhassi, Jarone
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    High Frequency Multi-Year Variability in Baltic Sea Microbial Plankton Stocks and Activities2019Ingår i: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 9, artikel-id 3296Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Marine bacterioplankton are essential in global nutrient cycling and organic matter turnover. Time-series analyses, often at monthly sampling frequencies, have established the paramount role of abiotic and biotic variables in structuring bacterioplankton communities and productivities. However, fine-scale seasonal microbial activities, and underlying biological principles, are not fully understood. We report results from four consecutive years of high-frequency time-series sampling in the Baltic Proper. Pronounced temporal dynamics in most investigated microbial variables were observed, including bacterial heterotrophic production, plankton biomass, extracellular enzyme activities, substrate uptake rate constants of glucose, pyruvate, acetate, amino acids, and leucine, as well as nutrient limitation bioassays. Spring blooms consisting of diatoms and dinoflagellates were followed by elevated bacterial heterotrophic production and abundances. During summer, bacterial productivity estimates increased even further, coinciding with an initial cyanobacterial bloom in early July. However, bacterial abundances only increased following a second cyanobacterial bloom, peaking in August. Uptake rate constants for the different measured carbon compounds varied seasonally and inter-annually and were highly correlated to bacterial productivity estimates, temperature, and cyanobacterial abundances. Further, we detected nutrient limitation in response to environmental conditions in a multitude of microbial variables, such as elevated productivities in nutrient bioassays, changes in enzymatic activities, or substrate preferences. Variations among biotic variables often occurred on time scales of days to a few weeks, yet often spanning several sampling occasions. Such dynamics might not have been captured by sampling at monthly intervals, as compared to more predictable transitions in abiotic variables such as temperature or nutrient concentrations. Our study indicates that high resolution analyses of microbial biomass and productivity parameters can help out in the development of biogeochemical and food web models disentangling the microbial black box.

  • 90.
    Bunse, Carina
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Lundin, Daniel
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Karlsson, Christofer M. G.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Akram, Neelam
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Vila-Costa, Maria
    Centre d’Estudis Avançats de Blanes-CSIC, Spain.
    Palovaara, Joakim
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Svensson, Lovisa
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Holmfeldt, Karin
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    González, José M.
    University of La Laguna, Spain.
    Calvo, Eva
    Institut de Ciències del Mar—CSIC, Spain.
    Pelejero, Carles
    Institut de Ciències del Mar—CSIC, Spain.
    Marrasé, Cèlia
    Institut de Ciències del Mar—CSIC, Spain.
    Dopson, Mark
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Gasol, Josep
    Institut de Ciències del Mar—CSIC, Spain.
    Pinhassi, Jarone
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Response of marine bacterioplankton pH homeostasis gene expression to elevated CO22016Ingår i: Nature Climate Change, ISSN 1758-678X, E-ISSN 1758-6798, Vol. 6, nr 5, s. 483-487Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Human-induced ocean acidification impacts marine life. Marine bacteria are major drivers of biogeochemical nutrient cycles and energy fluxes1; hence, understanding their performance under projected climate change scenarios is crucial for assessing ecosystem functioning. Whereas genetic and physiological responses of phytoplankton to ocean acidification are being disentangled2, 3, 4, corresponding functional responses of bacterioplankton to pH reduction from elevated CO2 are essentially unknown. Here we show, from metatranscriptome analyses of a phytoplankton bloom mesocosm experiment, that marine bacteria responded to lowered pH by enhancing the expression of genes encoding proton pumps, such as respiration complexes, proteorhodopsin and membrane transporters. Moreover, taxonomic transcript analysis showed that distinct bacterial groups expressed different pH homeostasis genes in response to elevated CO2. These responses were substantial for numerous pH homeostasis genes under low-chlorophyll conditions (chlorophyll a <2.5 μg l−1); however, the changes in gene expression under high-chlorophyll conditions (chlorophyll a >20 μg l−1) were low. Given that proton expulsion through pH homeostasis mechanisms is energetically costly, these findings suggest that bacterioplankton adaptation to ocean acidification could have long-term effects on the economy of ocean ecosystems.

  • 91. Burd, Adrian B.
    et al.
    Hansell, D. A.
    Steinberg, D. K.
    Anderson, T. R.
    Arístegui, J.
    Baltar, Federico
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Beaupré, S. R.
    Beusseler, K. O.
    DeHairs, F.
    Jackson, G. A.
    Kadko, D.
    Koppelmann, R.
    Lampitt, R. S.
    Nagata, T.
    Reinthaler, T.
    Robinson, C.
    Tamburini, C.
    Tanaka, T.
    Assessing the Apparent Imbalance Between Geochemical and Biochemical Indicators of Meso- and Bathypelagic Biological Activity: What the @$#! is wrong with present calculations of carbon budgets?2010Ingår i: Deep-sea research. Part II, Topical studies in oceanography, ISSN 0967-0645, E-ISSN 1879-0100, Vol. 57, nr 16, s. 1557-1571Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Metabolic activity in the water column below the euphotic zone is ultimately fuelled by the vertical flux of organic material from the surface. Over time, the deep ocean is presumably at steady state, with sources and sinks balanced. But recently compiled global budgets and intensive local field studies suggest that estimates of metabolic activity in the dark ocean exceed the influx of organic substrates. This imbalance indicates either the existence of unaccounted sources of organic carbon or that metabolic activity in the dark ocean is being over-estimated. Budgets of organic carbon flux and metabolic activity in the dark ocean have uncertainties associated with environmental variability, measurement capabilities, conversion parameters, and processes that are not well sampled. We present these issues and quantify associated uncertainties where possible, using a Monte Carlo analysis of a published data set to determine the probability that the imbalance can be explained purely by uncertainties in measurements and conversion factors. A sensitivity analysis demonstrates that the bacterial growth efficiencies and assumed cell carbon contents have the greatest effects on the magnitude of the carbon imbalance. Two poorly quantified sources, lateral advection of particles and a population of slowly settling particles, are discussed as providing a means of closing regional carbon budgets. Finally, we make recommendations concerning future research directions to reduce important uncertainties and allow a better determination of the magnitude and causes of the unbalanced carbon budgets. (C) 2010 Elsevier Ltd. All rights reserved.

  • 92.
    Caesar, Sofia
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Karlsson, Magnus
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Forsman, Anders
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Diversity and relatedness enhance survival in colour polymorphic grasshoppers2010Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 5, nr 5, artikel-id e10880Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Evolutionary theory predicts that different resource utilization and behaviour by alternative phenotypes may reduce competition and enhance productivity and individual performance in polymorphic, as compared with monomorphic, groups of individuals. However, firm evidence that members of more heterogeneous groups benefit from enhanced survival has been scarce or lacking. Furthermore, benefits associated with phenotypic diversity may be counterbalanced by costs mediated by reduced relatedness, since closely related individuals typically are more similar. Pygmy grasshoppers (Tetrix subulata) are characterized by extensive polymorphism in colour pattern, morphology, behaviour and physiology. We studied experimental groups founded by different numbers of mothers and found that survival was higher in low than in high density, that survival peaked at intermediate colour morph diversity in high density, and that survival was independent of diversity in low density where competition was less intense. We further demonstrate that survival was enhanced by relatedness, as expected if antagonistic and competitive interactions are discriminately directed towards non-siblings. We therefore also performed behavioural observations and staged encounters which confirmed that individuals recognized and responded differently to siblings than to non-siblings. We conclude that negative effects associated with competition are less manifest in diverse groups, that there is conflicting selection for and against genetic diversity occurring simultaneously, and that diversity and relatedness may facilitate the productivity and ecological success of groups of interacting individuals.

  • 93.
    Cao, Xianyong
    et al.
    Helmholtz Ctr Polar & Marine Res, Germany;Chinese Acad Sci, Peoples Republic of China.
    Tian, Fang
    Helmholtz Ctr Polar & Marine Res, Germany.
    Li, Furong
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Gaillard, Marie-José
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Rudaya, Natalia
    Helmholtz Ctr Polar & Marine Res, Germany;Russian Acad Sci, Russia;Univ Potsdam, Germany.
    Xu, Qinghai
    Hebei Normal Univ, Peoples Republic of China.
    Herzschuh, Ulrike
    Helmholtz Ctr Polar & Marine Res, Germany;Univ Potsdam, Germany.
    Pollen-based quantitative land-cover reconstruction for northern Asia covering the last 40 ka cal BP2019Ingår i: Climate of the Past, ISSN 1814-9324, E-ISSN 1814-9332, Vol. 15, nr 4, s. 1503-1536Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We collected the available relative pollen productivity estimates (PPEs) for 27 major pollen taxa from Eurasia and applied them to estimate plant abundances during the last 40 ka cal BP (calibrated thousand years before present) using pollen counts from 203 fossil pollen records in northern Asia (north of 40 degrees N). These pollen records were organized into 42 site groups and regional mean plant abundances calculated using the REVEALS (Regional Estimates of Vegetation Abundance from Large Sites) model. Time-series clustering, constrained hierarchical clustering, and detrended canonical correspondence analysis were performed to investigate the regional pattern, time, and strength of vegetation changes, respectively. Reconstructed regional plant functional type (PFT) components for each site group are generally consistent with modern vegetation in that vegetation changes within the regions are characterized by minor changes in the abundance of PFTs rather than by an increase in new PFTs, particularly during the Holocene. We argue that pollen-based REVEALS estimates of plant abundances should be a more reliable reflection of the vegetation as pollen may overestimate the turnover, particularly when a high pollen producer invades areas dominated by low pollen producers. Comparisons with vegetation-independent climate records show that climate change is the primary factor driving land-cover changes at broad spatial and temporal scales. Vegetation changes in certain regions or periods, however, could not be explained by direct climate change, e.g. inland Siberia, where a sharp increase in evergreen conifer tree abundance occurred at ca. 7-8 ka cal BP despite an unchanging climate, potentially reflecting their response to complex climate-permafrost-fire-vegetation interactions and thus a possible long-term lagged climate response.

  • 94. Carlsson, Per
    et al.
    Granéli, Edna
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Utilization of Dissolved Organic Matter (DOM) by Phytoplankton Including Harmful Species1998Ingår i: Physiological ecology of harmful algal blooms: proceedings of the NATO Advanced Study Institute on "The Physiological Ecology of Harmful Algal Blooms", held at the Bermuda Biological Station for Research, Bermuda, USA, May 27 - June 6, 1996 / [ed] Donald Mark Anderson, Allan D. Cembella, Heidelberg: Springer, 1998, s. 509-524Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 95.
    Carlsson, Per
    et al.
    Lunds Universitet.
    Granéli, Edna
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Granéli, Wilhelm
    Lunds Universitet.
    Gonzalez Rodriguez, Eliane
    IEAPM, Arraial do Cabo, Brazil .
    Carvalho, Wanderson F
    IEAPM, Arraial do Cabo, Brazil .
    Brutemark, Andreas
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Lindehoff, Elin
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Bacterial and phytoplankton nutrient limitation in tropical marine waters, and a coastal lake in Brazil2012Ingår i: Journal of Experimental Marine Biology and Ecology, ISSN 0022-0981, E-ISSN 1879-1697, Vol. 418-419, s. 37-45Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bioassay experiments were performed two times (with 2 years in between) in order to investigate if nitrogen(N, ammonium), phosphorus (P, phosphate) and carbon (C, glucose) additions would stimulate the growth ofbacteria and phytoplankton differently in three different tropical aquatic environments. The water and theirindigenous microbial communities were taken from a freshwater coastal lake (Cabiunas), a coastal (Anjos),and an offshore marine station (Sonar) in the Atlantic outside Cabo Frio, Rio de Janeiro State, Brazil. Ammonium,phosphate and glucose were added alone or in combination to triplicate bottles. In the lake, P seemedto be the primary limiting factor during the first experiment, since both bacterial production and phytoplanktongrowth was stimulated by the P addition. Two years later, however, addition of P inhibited phytoplanktongrowth. During both years, C was closely co-limiting for bacteria since CP additions increased the responseconsiderably. For both the coastal and offshore seawater stations, phytoplankton growth was clearly stimulatedby N addition in both years and the bacteria responded either to the P, N or C additions (alone or incombination). To conclude, the results from these tropical aquatic systems show that it is possible that phytoplanktonand bacteria may compete for a common resource (P) in lakes, but can be limited by different inorganicnutrients in marine waters as well as lakes, suggesting that phytoplankton and bacteria do notnecessarily compete for the same growth limiting nutrient in these environments.

  • 96. Carlsson, Per
    et al.
    Granéli, Edna
    Department of Marine Ecology, University of Lund .
    Olsson, P
    Grazer elimination through poisoning: one of the mechanisms behind Chrysochromulina polylepis blooms?1990Ingår i: Toxic marine phytoplankton: proceedings of the fourth International Conference on Toxic Marine Phytoplankton, held June 26-30 in Lund, Sweden / [ed] Edna Graneli, New York: Elsevier , 1990, s. 116-122Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 97.
    Carvalheiro, Luisa G.
    et al.
    Univ Fed Goias, Brazil;Univ Lisbon, Portugal.
    Biesmeijer, Jacobus C.
    Naturalis Biodivers Ctr, Netherlands;Leiden Univ, Netherlands.
    Franzén, Markus
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM). UFZ Ctr Environm Res, Germany.
    Aguirre-Gutierrez, Jesus
    Naturalis Biodivers Ctr, Netherlands;Univ Oxford, UK.
    Garibaldi, Lucas A.
    Universidad Nacional de Río Negro, Argentina;Consejo Nacl Invest Cient & Tecn CONICET, Argentina.
    Helm, Aveliina
    Univ Tartu, Estonia.
    Michez, Denis
    Univ Mons, Belgium.
    Poyry, Juha
    Finnish Environm Inst SYKE, Finland.
    Reemer, Menno
    Naturalis Biodivers Ctr, Netherlands;European Invertebrate Survey Netherlands, Netherlands.
    Schweiger, Oliver
    UFZ Ctr Environm Res, Germany.
    van den Berg, Leon
    Bosgrp Zuid Nederland, Netherlands;Radboud Univ Nijmegen, Netherlands.
    WallisDeVries, Michiel F.
    De Vlinderstichting Dutch Butterfly Conservat, Netherlands;Wageningen Univ, Netherlands.
    Kunin, William E.
    Univ Leeds, UK.
    Soil eutrophication shaped the composition of pollinator assemblages during the past century2020Ingår i: Ecography, ISSN 0906-7590, E-ISSN 1600-0587, Vol. 43, s. 209-221Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Atmospheric nitrogen deposition and other sources of environmental eutrophication have increased substantially over the past century worldwide, notwithstanding the recent declining trends in Europe. Despite the recognized susceptibility of plants to eutrophication, few studies evaluated how impacts propagate to consumers, such as pollinators. Here we aim to test if soil eutrophication contributes to the temporal dynamics of pollinators and their larval resources. We used a temporally and spatially explicit historical dataset with information on species occurrences to test if soil eutrophication, and more specifically nitrogen deposition, contributes to the patterns of change of plant and pollinator richness in the Netherlands over an 80 yr period. We focus on bees and butterflies, two groups for which we have good knowledge of larval resources that allowed us to define groups of species with different nitrogen related diet preferences. For each group we estimated richness changes between different 20-yr periods at local, regional and national scale, using analytical methods developed for analyzing richness changes based on collection data. Our findings suggest that the impacts of soil eutrophication on plant communities propagate to higher trophic levels, but with a time-lag. Pollinators with nitrogen-related diet preferences were particularly affected, in turn potentially impairing the performance of pollinator-dependent plants. Pollinator declines continued even after their focal plants started to recover. In addition, our results suggest that current levels of nitrogen deposition still have a negative impact on most groups here analyzed, constraining richness recoveries and accentuating declines. Our results indicate that the global increase in nitrogen availability plays an important role in the ongoing pollinator decline. Consequently, species tolerances to soil nitrogen levels should be considered across all trophic levels in management plans that aim to halt biodiversity loss and enhance ecosystems services worldwide.

  • 98.
    Carvalho, Wanderson
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Minnhagen, Susanna
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Granéli, Edna
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Dinophysis norvegica (Dinophyceae), more a predator than a producer?2008Ingår i: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 7, nr 2, s. 174-183Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Several studies have proved that some Dinophysis species are capable of ingesting particulate organic matter besides of being photosynthetic, a form of nutrition termed mixotrophy. Phagotrophy may be an important aspect of the life history of the genus Dinophysis and the key to understand its ecology. We used modern techniques coupling flow cytometry and acidotropic probes to detect and score food vacuolated Dinophysis norvegica cells in natural samples. In addition, feeding experiments were conduced under controlled conditions to observe if D. norvegica would grow feeding on the cryptophyte Teleaulax amphioxeia. The results of the field observations showed a frequency of phagotrophy between 25 and 71% in a natural D. norvegica population from the Baltic Sea, which is higher than previous reports (1–20%). Although molecular methods have proved that the kleptoplastids of the D. norvegica from the Baltic Sea are from T. amphioxeia, the laboratory experiments showed that the presence of T. amphioxeia in the cultures did not enhance the survival rate of D. norvegica neither in phototrophic nor in heterotrophic conditions. We suggest that the D. norvegica Kleptoplats are obtained through a heterotrophic or mixotrophic protist, which have been feeding on cryptophytes, as it has recently been shown for Dinophysis acuminata. Our main conclusion is that D. norvegica, and probably all other species from the genus Dinophysis, is mainly phagotrophic and feeds on a larger prey than T. amphioxeia. Autotrophy through kleptoplastidy would be a secondary feature used as a complementary or short-term survival strategy. 

  • 99.
    Cederlund, Göran
    et al.
    Grimsö Wildlife Research Station, Sweden.
    Sandegren, Finn
    Swedish Sportsmen's Association, Sweden.
    Larsson, Kjell
    Swedish Sportsmen's Association, Sweden.
    Summer movements of female moose and dispersal of their offspring1987Ingår i: Journal of Wildlife Management, ISSN 0022-541X, E-ISSN 1937-2817, Vol. 51, nr 2, s. 342-352Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Fifty-seven radio-equipped moose (Alces alces) in central Sweden were located during the 3 summers of 1980-83. Forty-two were cows (≤2 years old) and 15 were calves (5 males and 10 females) when captured. Aerial tracking was conducted ≤1 time/week. No significant differences in average size of summer home ranges were found between age classes. All cows returned to the same summer range each spring. Consecutive summer home ranges overlapped from 1 to 100%. Ten of 14 radio-equipped calves accompanied their cow to summer ranges. The 1st indications of separation between cow and offspring were recorded from 7 to 29 May. The average straight line distance between cow and offspring successively increased from separation to mid-June when it became relatively constant (1.5-2.0 km). One of 10 calves that completed the migration together with the cow abandoned its mother's home range completely. Adult female offspring continued to reside near their yearling home range during consecutive summers.

  • 100.
    Cederlöf, Gunnel
    et al.
    Linnéuniversitetet, Fakulteten för konst och humaniora (FKH), Institutionen för kulturvetenskaper (KV).
    Rangarajan, MaheshAshoka University, India.
    Nature and History: A Symposium on Human-Nature Relations in the Longterm2015Samlingsverk (redaktörskap) (Refereegranskat)
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