Vegetation is of central importance for upholding biodiversity and for determining global carbon flows, with vegetation models playing an essential part in predictions of human-induced climate change. EEP’s research on evolutionary vegetation modeling and management aims to improve models of the formation and maintenance of vegetation diversity, structure, and functioning. It is carried out in close collaboration with IIASA’s ASA and ESM Programs.
Whereas EEP’s research efforts in preceding years have focused on forest dynamics, investigations in 2013 focused on understanding the availability of plant nutrients and how nutrient supply is mediated by soil fungi and bacteria.
A study of the temporal dimension of these questions showed how seasonal changes influence functional properties of microbial communities . The underlying mechanisms that facilitate plant nutrient uptake was also studied and revealed how fungal and bacterial utilization of organic substrates depends on substrate complexity and nitrogen availability .
These findings were complemented by investigating the dynamics of nitrogen transfer in permafrost soils .
Finally, a new facet of EEP’s research on evolutionary vegetation modeling was established through an investigation of the spatial dynamics of aquatic plankton communities .
Accurately predicting terrestrial carbon fluxes in response to changing environmental conditions requires accounting for soil dynamics in biogeochemical models. While it is widely believed that such dynamics are determined stoichiometrically, a new EEP study published in Ecology Letters challenges this view . Introducing an innovative spatially structured individual-based model of soil dynamics (Figure 1), it is demonstrated how community-level adaptations allow functionally diverse groups of microbial decomposers to overcome large stoichiometric imbalances without decreasing carbon-use efficiency.
Figure 1. A new systems model of soil dynamics developed in EEP. Colors in the left panel describe three types of microbial decomposers (blue: plant degraders, green: necromass degraders, red: opportunistic degraders), whose abundance and spatial configurations change over time in a way classical stochiometric theory cannot predict.
 Koranda M, Kaiser C, Fuchslueger L, Kitzler B, Sessitsch A, Zechmeister-Boltenstern S & Richter A (2013). Seasonal variation in functional properties of microbial communities in beech forest soil. Soil Biology and Biochemistry 60: 95–104.
 Koranda M, Kaiser C, Fuchslueger L, Kitzler B, Sessitsch A, Zechmeister-Boltenstern S & Richter A (2014). Fungal and bacterial utilization of organic substrates depends on substrate complexity and N availability. FEMS Microbiology Ecology 87: 142–152.
 Wild B, Schnecker J, Barta J, Capek P, Guggenberger G, Hofhansl F, Kaiser C, Lashchinsky N, Mikutta R, Mooshammer M, Santruckova H, Shibistova O, Urich T, Zimov SA & Richter A (2013). Nitrogen dynamics in Turbic Cryosols from Siberia and Greenland. Soil Biology and Biochemistry 67: 85–93.
 Della Rossa F, Fasani S & Rinaldi S (2013). Conditions for patchiness in plankton models. Theoretical Population Biology 83: 95–100.
 Kaiser C, Franklin O, Dieckmann U & Richter A (2014). Microbial community dynamics alleviate stoichiometric constraints during litter decay. Ecology Letters, in press. doi: 10.1111/ele.12269.
Last edited: 22 May 2014
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