Research
Ecological stoichiometry in benthic ecosystems
The aim of my research is to identify general structuring mechanisms and investigate nutrient pathways in benthic lake and river ecosystems. I do this within the framework of ecological stoichiometry theory. Ecological stoichiometry is defined as the balance of multiple chemical substances in ecological interactions and explicitly considers the combined dynamics of key elements such as carbon (C), nitrogen (N) and phosphorus (P).
Species diversity patterns
Several factors have been shown to affect species richness and species diversity in a given habitat. My aim is to find out how biotic (consumption/predation) and abiotic factors (light, nutrients, and nutrient ratios) affect species richness of primary producers and consumers. I am using benthic river ecosystems as model communities to derive ecological patterns.
N deposition
Anthropogenic N-deposition is increasing from the north to the south in Sweden. This gradient decreases the supply ratios of dissolved N:P to lakes towards the north and leads to a switch in benthic algal nutrient limitation from N limitation in the north to P limitation in the south. I am testing how this latitudinal gradient in N:P supply ratios affects nutrient dynamics in lake benthic ecosystems.
Current projects
I. Benthic algal responses to temperature and nutrient regime
II. Consumer growth rates and nutritional constraints across latitudinal gradients – combining ecology and evolution
III. TOP-UP - Top down versus bottom up effects in aquatic food webs.
Older Publications (peer reviewed)
Book chapter
1) Molau U, Kling J, Lindblad K, Björk R, Dänhardt J & Liess, A (2003) Chapter 11: "A GIS assessment of alpine biodiversity at a range of scales" In Grabherr, G., Nagy, L., Thompson, D. B. A., and Körner, C. (eds.), Alpine Biodiversity in Europe. - Ecological Studies, vol 167. Springer-Verlag, Berlin.
Peer reviewed journal articles
2) Liess A and Hillebrand H (2004). Direct and indirect effects in herbivore - periphyton interactions, Archiv für Hydrobiologie, 159: 433-453.
3) Hillebrand H, DeMontpellier G and Liess A (2004). Effects of macrograzers and light on periphyton stoichiometry, Oikos, 106: 93-104.
4) Kay A D, Ashton I W, Gorokhova E, Kerkhoff A J, Liess A and Litchman E (2005) Toward a stoichiometric framework for evolutionary biology. Oikos, 109: 6-17.
5) Liess A and Hillebrand H (2005) Stoichiometric variation in C:N, C:P and N:P ratios of littoral benthic invertebrates, JNABS, 24: 256-269.
6) Liess A, Quevedo M, Olsson J, Vrede T, Eklöv P and Helmut H (2006) Food web complexity affects stoichiometric and trophic interactions. Oikos 114: 117-125
7) Liess A and Diehl S. (2006) Effects of enrichment on protist abundances and bacterial composition in simple microbial communities. Oikos 114:15-26
8) Liess A and Hillebrand H. (2006) Role of nutrient supply in grazer-periphyton interactions: reciprocal influences of periphyton and grazer nutrient stoichiometry. JNABS 25(3): 632-642
9) Liess A. and Kahlert M. (2007) Grastropod grazers and nutrients, but not light, interact in determining periphytic algal diversity. Oecologia 152:101-111
10) Liess A and Haglund A-L (2007) Periphyton responds differentially to nutrients recycled by the snail grazer Theodoxus fluviatilis in dissolved or fecal pellet form. Freshwater Biology, 52:1997-2008
11) Hillebrand H, Frost P and Liess A. (2008) Ecological stoichiometry of herbivore-plant interactions - a meta-analysis using periphyton experiments. Oecologia 155:619-630
12) Liess A, Lange K, Piggott, JJ, Matthaei DC and Townsend RC (2009). Light, nutrients and grazing interact to determine diatom species richness via changes to productivity, nutrient state and grazer activity. Journal of Ecology 97: 326-336
13) Liess A and Kahlert M. (2009) Gastropod grazers affect periphyton nutrient stoichiometry by changing benthic algal taxonomy and through differential nutrient uptake. JNABS, 28: 283-293
14) Liess A, Dakare S, Kahlert M. (2009) Atmospheric nitrogen-deposition may intensify phosphorous limitation of shallow epilithic periphyton in unproductive lakes. Freshwater Biology 54: 1759-1773.
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