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Bartels, Pia
Publications (3 of 3) Show all publications
Bartels, P., Hirsch, P. E., Svanbäck, R. & Eklöv, P. (2016). Dissolved Organic Carbon Reduces Habitat Coupling by Top Predators in Lake Ecosystems. Ecosystems (New York. Print), 19, 955-967
Open this publication in new window or tab >>Dissolved Organic Carbon Reduces Habitat Coupling by Top Predators in Lake Ecosystems
2016 (English)In: Ecosystems (New York. Print), ISSN 1432-9840, E-ISSN 1435-0629, Vol. 19, p. 955-967Article in journal (Refereed) Published
Abstract [en]

Increasing input of terrestrial dissolved organic carbon (DOC) has been identified as a widespread environmental phenomenon in many aquatic ecosystems. Terrestrial DOC influences basal trophic levels: it can subsidize pelagic bacterial production and impede benthic primary production via light attenuation. However, little is known about the impacts of elevated DOC concentrations on higher trophic levels, especially on top consumers. Here, we used Eurasian perch (Perca fluviatilis) to investigate the effects of increasing DOC concentrations on top predator populations. We applied stable isotope analysis and geometric morphometrics to estimate long-term resource and habitat utilization of perch. Habitat coupling, the ability to exploit littoral and pelagic resources, strongly decreased with increasing DOC concentrations due to a shift toward feeding predominantly on pelagic resources. Simultaneously, resource use and body morphology became increasingly alike for littoral and pelagic perch populations with increasing DOC, suggesting more intense competition in lakes with high DOC. Eye size of perch increased with increasing DOC concentrations, likely as a result of deteriorating visual conditions, suggesting a sensory response to environmental change. Increasing input of DOC to aquatic ecosystems is a common result of environmental change and might affect top predator populations in multiple and complex ways.

Keywords
allochthony, brownification, food web coupling, visibility, foraging, climate change
National Category
Biological Sciences
Identifiers
urn:nbn:se:uu:diva-294185 (URN)10.1007/s10021-016-9978-x (DOI)000386710000001 ()
Available from: 2016-05-18 Created: 2016-05-18 Last updated: 2017-10-17Bibliographically approved
Bartels, P., Cucherousset, J., Steger, K., Eklöv, P., Tranvik, L. J. & Hillebrand, H. (2012). Reciprocal subsidies between freshwater and terrestrial ecosystems structure consumer-resource dynamics. Ecology, 93(5), 1173-1182
Open this publication in new window or tab >>Reciprocal subsidies between freshwater and terrestrial ecosystems structure consumer-resource dynamics
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2012 (English)In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 93, no 5, p. 1173-1182Article in journal (Refereed) Published
Abstract [en]

Cross-ecosystem movements of material and energy, particularly reciprocal resource fluxes across the freshwater-land interface, have received major attention. Freshwater ecosystems may receive higher amounts of subsidies (i.e., resources produced outside the focal ecosystem) than terrestrial ecosystems, potentially leading to increased secondary production in freshwaters. Here we used a meta-analytic approach to quantify the magnitude and direction of subsidy inputs across the freshwater-land interface and to determine subsequent responses in recipient animals. Terrestrial and freshwater ecosystems differed in the magnitude of subsidies they received, with aquatic ecosystems generally receiving higher subsidies than terrestrial ecosystems. Surprisingly, and despite the large discrepancy in magnitude, the contribution of these subsidies to animal carbon inferred from stable isotope composition did not differ between freshwater and terrestrial ecosystems, likely due to the differences in subsidy quality. The contribution of allochthonous subsidies was highest to primary consumers and predators, suggesting that bottom-up and top-down effects may be affected considerably by the input of allochthonous resources. Future work on subsidies will profit from a food web dynamic approach including indirect trophic interactions and propagating effects.

National Category
Ecology
Identifiers
urn:nbn:se:uu:diva-160772 (URN)10.1890/11-1210.1 (DOI)000304368100022 ()
Available from: 2011-10-31 Created: 2011-10-31 Last updated: 2017-12-08Bibliographically approved
Bartels, P., Cucherousset, J., Gudasz, C., Jansson, M., Karlsson, J., Persson, L., . . . Eklöv, P. (2012). Terrestrial subsidies to lake food webs: An experimental approach. Oecologia, 168(3), 807-818
Open this publication in new window or tab >>Terrestrial subsidies to lake food webs: An experimental approach
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2012 (English)In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 168, no 3, p. 807-818Article in journal (Refereed) Published
Abstract [en]

Cross-ecosystem movements of material and energy are ubiquitous. Aquatic ecosystems typically receive material that also includes organic matter from the surrounding catchment. Terrestrial-derived (allochthonous) organic matter can enter aquatic ecosystems in dissolved or particulate form. Several studies have highlighted the importance of dissolved organic carbon to aquatic consumers, but less is known about allochthonous particulate organic carbon (POC). Similarly, most studies showing the effects of allochthonous organic carbon (OC) on aquatic consumers have investigated pelagic habitats; the effects of allochthonous OC on benthic communities are less well studied. Allochthonous inputs might further decrease primary production through light reduction, thereby potentially affecting autotrophic resource availability to consumers. Here, an enclosure experiment was carried out to test the importance of POC input and light availability on the resource use in a benthic food web of a clear-water lake. Corn starch (a C-4 plant) was used as a POC source due to its insoluble nature and its distinct carbon stable isotope value (delta C-13). The starch carbon was closely dispersed over the bottom of the enclosures to study the fate of a POC source exclusively available to sediment biota. The addition of starch carbon resulted in a clear shift in the isotopic signature of surface-dwelling herbivorous and predatory invertebrates. Although the starch carbon was added solely to the sediment surface, the carbon originating from the starch reached zooplankton. We suggest that allochthonous POC can subsidize benthic food webs directly and can be further transferred to pelagic systems, thereby highlighting the importance of benthic pathways for pelagic habitats.

Keywords
Allochthonous, Cross-ecosystem, Autochthonous, Aquatic-terrestrial linkage, Benthic
National Category
Ecology
Identifiers
urn:nbn:se:uu:diva-160774 (URN)10.1007/s00442-011-2141-7 (DOI)000301706800020 ()
Available from: 2011-10-31 Created: 2011-10-31 Last updated: 2017-12-08Bibliographically approved
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