Chapin and Körner 1994

Chapin FS III, Körner C. 1994. Arctic and alpine biodiversity: patterns, causes and ecosystem consequences. Trends in Ecology and Evolution 9: 45-47.

These authors summarize the major points discussed at a meeting in Norway of researchers studying Arctic and alpine ecosystems, in the context of climate change and 14 major biomes. No published works are cited in this paper, rather several prominent researchers are mentioned as contributing various components of the meeting.

Arctic and alpine ecosystems were grouped together and described as “critical” for five reasons: 1. High latitudes are expected to experience the most change in climate; 2. The ecological consequences of warming will be most severe in cold regions; 3. High altitudes with low atmospheric pressures are expected to be most limiting for CO2 and consequently will respond strongly to changes in CO2 concentrations; 4. Arctic systems include large pools of frozen carbon and methane, and will thus generate important feedback effects during warming; 5. Arctic and alpine ecosystems are relatively simple systems and may show clear effects on species of ecosystem processes. Point 5 is probably most directly applicable to my own work, in that it reinforces the utility of low-species-richness and extreme-climate environments for examinations of interactions between abiotic factors and evolutionary processes.

Much of the discussion centres on the Arctic and alpine flora, which show patterns of diversity strongly associated with historical forces such as the Pleistocene glaciations. Arctic floras tend to be broadly distributed, often holarctic, while most alpine systems are more specific to small areas. In general, stable Arctic and alpine systems show diversity curves that fit the geometric model, suggesting that competitive interactions for limiting resources best explain patterns of diversity, rather than abiotic factors.

In contrast, animal diversity shows a clear latitudinal and altitudinal gradient, with associated patterns of taxonomic replacement. For example, coleopteran species richness declines with latitude while dipteran species richness increases.

The processes that humans are most interested in for economic and other reasons are those most sensitive to species composition, such as pollination and trophic dynamics. Other processes are much less sensitive to species composition within functional groups, for example many biogeochemistry processes.

In summary, the described conference demonstrated that a great deal is known about patterns of biodiversity in Arctic and alpine ecosystems as well as globally. These patterns appear to have important consequences for ecosystem function, and further research is urged in refining knowledge of species diversity patterns to better detect changes due to climate, experimental manipulations simulating changes in climate and CO2, and simulation modelling of long-term and large-scale processes.