Title: Spatio-temporal dynamics of terrestrial vertebrates in a high Arctic community: responses to changes in climatic and biotic environments
This study analytically contrasts and compares how selected terrestrial high Arctic species respond in behaviour, life history traits and abundance to changes in climate and biological processes.
The forcing and feedback mechanisms of the Arctic climate are considered to be a key element in the numerical modelling of global climate change. Hence, interactions between climate and ecosystem structure and functioning in the Arctic may provide us with important clues in understanding general ecological consequences following large-scale climatic changes, such as global warming.
Disentangling the relative influences of climatic and biological processes is at the heart of climate change ecology. In some species, biological interactions may be important, whereas others may be more influenced by climate. Then again, climate may be important but only under specific biological conditions, such as high densities. In other words, ecological responses to climatic and biotic variability are complex and neither process should be studied in isolation.
So far, the integration of climatic and biotic environmental variables into climate change ecology studies has been constrained by the lack of detailed and contemporary long-term data. However, the long-term, multidisciplinary monitoring programme Zackenberg Ecological Research Operations (ZERO) in Northeast Greenland, provides an excellent foundation for such complex studies of the interface between climate and ecology.
Since the implementation in 1995, a suite of monitoring programmes under ZERO has, annually through 5-6 months, collected comprehensive and detailed data on most biological and climatological components of the local ecosystem. Together with additional long-time observational and hunting time series, present PhD study utilises these data analytically by contrasting and comparing how selected Arctic species respond to changes in climatic and biotic conditions. The study focuses on the responses of evolutionary distinct species and, hence, how responses are related to different life histories and different trophic levels.
Through ecological modelling and spatio-temporal statistical analyses, species-specific variations in abundance, breeding performance and habitat use of 5 bird species (ringed plover, sanderling, dunlin, turnstone, long-tailed skua) and 3 mammal species (collared lemming, muskox, polar fox) are related to seasonal and interannual variability in (1) regional climatic conditions (temperature, precipitation, wind, snow cover), (2) large-scale climatic conditions mediated through the Arctic Oscillation, (3) distribution of habitats, (4) forage availability and quality, (5) distribution and abundance of predators and (6) density-dependent intra- and interspecific interactions.
Analyses will employ recent autoregressive models as well as spatio-temporal cross-correlation analyses. Analyses and results will be interpreted in relation to multitrophic population models embracing inter-trophic (predator-prey, plant-herbivore) and intra-trophic (conspecific, species-species ) interactions.
Copenhagen University contact person
Mads C. Forchhammer, assoc. research professor
Dept. of Population Ecology, Zoological Institute,
University of Copenhagen,
DK-2100 Copenhagen E, Denmark