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Leberfinger, Karolina
Publications (8 of 8) Show all publications
Leberfinger, K., Bohman, I. & Herrmann, J. (2011). The importance of terrestrial resource subsidies for shredders in open-canopy streams revealed by stable isotope analysis. Freshwater Biology, 56(3), 470-480
Open this publication in new window or tab >>The importance of terrestrial resource subsidies for shredders in open-canopy streams revealed by stable isotope analysis
2011 (English)In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 56, no 3, p. 470-480Article in journal (Refereed) Published
Abstract [en]

1. Allochthonous detritus is the major source of energy in forested streams, but less is known of the importance of terrestrial subsidies to open-canopy streams. Here, we used stable isotope analysis to assess the importance of allochthonous versus autochthonous energy sources to invertebrate shredders in four open-canopy streams in Sweden. Shredders and potential food sources were analysed at both open sites and those with deciduous trees in the riparian zone.2. Mixing models showed that allochthonous coarse particulate organic matter was the most important energy source to shredders at both the open and wooded sites, suggesting that terrestrial subsidies may be an important process in open-canopy streams, just as they are in forested streams.3. However, shredders at open sites had a larger proportion of biofilm in their diet than at wooded sites, indicating an ability of shredders to adjust their diet with food availability.4. We also used the carbon and nitrogen stable isotope signatures to assess the size of the feeding niche of shredders. Feeding on both allochthonous and autochthonous sources at open sites was reflected in a larger feeding niche than at wooded sites for one of the three species analysed. There was substantial overlap of the feeding niche among shredder species, indicating a high functional redundancy within this guild.

National Category
Ecology
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-2993 (URN)10.1111/j.1365-2427.2010.02512.x (DOI)2-s2.0-79551676593 (Scopus ID)
Available from: 2010-04-23 Created: 2010-04-23 Last updated: 2017-12-12Bibliographically approved
Leberfinger, K., Bohman, I. & Herrmann, J. (2010). Drought impact on stream detritivores - experimental effects on leaf litter breakdown and life cycles. Hydrobiologia, 652(1), 247-254
Open this publication in new window or tab >>Drought impact on stream detritivores - experimental effects on leaf litter breakdown and life cycles
2010 (English)In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 652, no 1, p. 247-254Article in journal (Refereed) Published
Abstract [en]

Predictions of effects of global climate change include decreased runoff for many parts of the world, which will result in drying of streams. Information of the effects of drought on aquatic ecosystems is limited and little is known of the effects on ecosystem functions. Our main objective was to measure the direct effects of drought on leaf litter breakdown by invertebrate shredders in a controlled laboratory experiment. We hypothesized a decreased breakdown at high drought level. Single-species and multi-species treatments with three shredder species (Asellus aquaticus, Limnephilus bipunctatus, and L. flavicornis) were set up in an experiment with three drought level treatments, control, medium, and high drought (6 cm water level, 1 cm water level, and water level below sediment surface, respectively). Breakdown measured as leaf litter loss was significantly lower in both medium and high drought treatments compared to the control. Previously, decreased breakdown due to drying has been reported, but attributed to low densities of invertebrate shredders. We show that even when shredders are present, drought decreases the breakdown. Drought treatments also induced earlier pupation for the caddisfly L. flavicornis. Shifts in species phenology due to drought, e.g., earlier emergence, may affect species ability to adult survival and reproduction. Shifts in timing of emergence may also affect terrestrial food webs, where emerging aquatic insects may constitute an important food subsidy. Our knowledge of the complex effects of droughts in aquatic systems is limited with an urgent need of extended knowledge of the ecological effects of droughts on freshwater ecosystem functioning.

National Category
Ecology
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-2995 (URN)10.1007/s10750-010-0337-1 (DOI)2-s2.0-77954665567 (Scopus ID)
Available from: 2010-04-23 Created: 2010-04-23 Last updated: 2017-12-12Bibliographically approved
Leberfinger, K. & Bohman, I. (2010). Grass, mosses, algae or leaves? Food preference among shredders from open-canopy streams. Aquatic Ecology, 44(1), 195-203
Open this publication in new window or tab >>Grass, mosses, algae or leaves? Food preference among shredders from open-canopy streams
2010 (English)In: Aquatic Ecology, ISSN 1386-2588, E-ISSN 1573-5125, Vol. 44, no 1, p. 195-203Article in journal (Refereed) Published
Abstract [en]

Shredder feeding is a vital process in making decomposition products available to biota in streams. To investigate which food sources shredders in open-canopy streams exploit, we conducted a feeding preference experiment with the invertebrate detritivores Limnephilus bipunctatus and Nemoura sp., which are commonly found in open-canopy streams on the Swedish island of A-land in the southern Baltic Sea. Leaves of birch, Swedish whitebeam, and shrubby cinquefoil; dead and fresh grass; water moss; and algae were offered to the shredders in multi- and single treatments. We hypothesized that food with high nutritional value would be preferred. Both taxa preferred leaves of shrubby cinquefoil, a bush common in the riparian zone of A-land streams; additionally Nemoura sp. also chose algae. Dead grass, the most abundant food source in the streams during the whole year, was the least consumed food type. The fresh food types had highest nutritional value, measured as carbon to nitrogen content. Therefore, food quality could not alone explain the preference of shrubby cinquefoil. However, among the detritus type offered, shrubby cinquefoil had the highest nutritional value. Shrubby cinquefoil may constitute one important energy source to these open-canopy stream ecosystems and may be essential in maintaining an abundant shredder community in these streams. Thus, the results of this study indicate that detrital resources are indeed important in open-canopy stream systems.

National Category
Ecology
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-2025 (URN)10.1007/s10452-009-9268-1 (DOI)
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-12-12Bibliographically approved
Leberfinger, K. (2010). Revealing the role of shredders and detritus in open-canopy, intermittent streams. (Doctoral dissertation). Växjö: Linnaeus University Press
Open this publication in new window or tab >>Revealing the role of shredders and detritus in open-canopy, intermittent streams
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Many streams run through naturally-unforested, agricultural, and residential landscapes and thus do not have closed riparian canopies. Little is known of food web dynamics and ecosystem function in such open-canopy streams. Similarly, our knowledge of ecosystem processes in intermittent streams and effects of drought on stream ecosystem function are limited, despite that predictions of climate change effects include increased frequency and duration of droughts in freshwaters. The aim of my thesis was to increase our knowledge of invertebrate shredder assemblages and ecosystem function in open-canopy intermittent streams and to reveal the role of terrestrial organic matter in open-canopy streams. Invertebrate shredders, as primary consumers of detritus, significantly contribute to the ecosystem function decomposition of organic matter. Thereby, shredders are important vectors for transferring detrital energy into stream food webs.

I found high-density and species-rich shredder assemblages in three open-canopy intermittent streams on the island of Öland in the southern Baltic Sea, Sweden. My results showed that terrestrially derived organic matter was the shredder’s main food source and the amount of high-quality CPOM potentially limited shredder production. However, through supplementing their feeding with algae, a high shredder production, similar to production estimates in forested permanent streams, could be maintained in these open-canopy intermittent streams. Instead, my results indicate that the primary physical factor constraining shredder production in intermittent streams is the length of the summer drought period. Furthermore, drying simulated as decreasing water levels in an experiment, decreased invertebrate shredder feeding activity and consequently, the breakdown rate of organic matter. Drying also altered a caddisfly shredders’ life cycle phenology and such evident induction of earlier pupation due to drying has not been shown for aquatic insects earlier.

Food webs and ecosystem function and processes in open-canopy and intermittent streams deserve further attention, especially as these types of streams are very common worldwide. My findings indicate that the energy base in open-canopy streams may be terrestrially derived organic matter, as in forested streams, but constraints imposed by habitat traits and differences in organic matter input size may have significant consequences on stream productivity. My results may be important for increased understanding of potential effects of land use changes (i.e. forestry, agriculture, urbanization) and environmental changes (i.e. climate change) on stream ecosystems.

Place, publisher, year, edition, pages
Växjö: Linnaeus University Press, 2010
Series
Linnaeus University Dissertations ; 18/2010
National Category
Ecology
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-2996 (URN)978-91-86491-23-9 (ISBN)
Public defence
2010-05-28, Fullriggaren, Landgången 4, Kalmar, 09:30 (English)
Opponent
Supervisors
Available from: 2010-04-23 Created: 2010-04-23 Last updated: 2010-04-23Bibliographically approved
Leberfinger, K. & Herrmann, J. (2010). Secondary production of invertebrate shredders in open-canopy, intermittent streams on the island of Öland, SE Sweden. Journal of The North American Benthological Society, 29, 934-944
Open this publication in new window or tab >>Secondary production of invertebrate shredders in open-canopy, intermittent streams on the island of Öland, SE Sweden
2010 (English)In: Journal of The North American Benthological Society, ISSN 0887-3593, E-ISSN 1937-237X, Vol. 29, p. 934-944Article in journal (Refereed) Published
Abstract [en]

Knowledge of functional aspects of communities in intermittent streams currently is lacking, and the role of terrestrial detritus as a resource in open-canopy streams is uncertain. Our main objective was to characterize and quantify the macroinvertebrate shredder assemblages in 3 intermittent open-canopy streams on the island of Öland in the Baltic Sea, Sweden, by estimating secondary production. Estimates of annual shredder secondary production ranged from 0.005 to 13.6 g ash-free dry mass (AFDM) m−2 y−1 among sites. Shredder production and amount of organic matter were positively related, but shredder production was more strongly influenced by the duration of the summer dry period. Production decreased with increase in the length of the summer dry period, but shredder production was still high at sites with long dry phases and was comparable to estimates of shredder production in permanent forested streams, results suggesting that terrestrial organic matter might be an important energy resource in open-canopy streams. Shredder species richness decreased with increase in length of the summer dry phase, and shredder species composition at sites with a long dry period was dominated by drought-tolerant taxa. Our results suggest that ecosystem functions might shift from being sustained by many taxa to being sustained by fewer taxa as stream ecosystems experience moderate droughts of similar length (2–4 mo).

Keywords
temporary streams, detritivore, life cycle, organic matter, limited leaf-litter input, species richness
National Category
Ecology
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-2992 (URN)10.1899/09-179.1 (DOI)2-s2.0-77954881338 (Scopus ID)
Available from: 2010-04-23 Created: 2010-04-23 Last updated: 2017-12-12Bibliographically approved
Leberfinger, K. & Herrmann, J. (2010). Spatial and temporal distribution of shredders in leaf-limited intermittent streams. In: Verhandlungen Internat. Verein. Limnol 30: . Paper presented at 30th Congress of the International Association of Theoretical and Applied Limnology (pp. 1342-1344). Stuttgart: E. Schweizerbart'sche Verlagsbuchhandlung
Open this publication in new window or tab >>Spatial and temporal distribution of shredders in leaf-limited intermittent streams
2010 (English)In: Verhandlungen Internat. Verein. Limnol 30, Stuttgart: E. Schweizerbart'sche Verlagsbuchhandlung, 2010, p. 1342-1344Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Stuttgart: E. Schweizerbart'sche Verlagsbuchhandlung, 2010
National Category
Ecology
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-5052 (URN)
Conference
30th Congress of the International Association of Theoretical and Applied Limnology
Available from: 2010-04-28 Created: 2010-04-28 Last updated: 2016-04-20Bibliographically approved
Lagergren, R., Leberfinger, K. & Stenson, J. A. E. (2008). Seasonal and ontogenetic variation in diel vertical migration of Chaoborus flavicans and its effect on depth-selection behavior of other zooplankton. Limnology and Oceanography, 53(3), 1083-1092
Open this publication in new window or tab >>Seasonal and ontogenetic variation in diel vertical migration of Chaoborus flavicans and its effect on depth-selection behavior of other zooplankton
2008 (English)In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 53, no 3, p. 1083-1092Article in journal (Refereed) Published
National Category
Natural Sciences
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-2024 (URN)
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-12-12Bibliographically approved
Leberfinger, K., Herrmann, J., Hoover, T. M., Bohman, I. & Richardson, J. S.Modelling climatic change effects of decomposition processes in small streams.
Open this publication in new window or tab >>Modelling climatic change effects of decomposition processes in small streams
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Ecology
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-2994 (URN)
Available from: 2010-04-23 Created: 2010-04-23 Last updated: 2012-01-03Bibliographically approved
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