The application of multivariate techniques in assessing the effects of climate change on biodiversity at different spatial scales

The Centre for Ecology and Hydrology, in collaboration with Oxford University, has developed a European environmental classification for the assessment and monitoring of effects of climate change on biodiversity at different spatial scales. The classification was constructed using various multivariate techniques from the database for 5500 half by half degree cells for the wider European window, developed by the University of East Anglia (UEA) for the TIGER programme. A statistical rule set created from the classification allows any cell size down to 1 x 1 km to be allocated to one of the 64 classes from its climate and altitude characteristics. Currently, this procedure has been used at its original resolution of half by half degree cell size across Europe and at a 10 x 10 km cell size across Great Britain. A number of climate change scenarios from different climate models provided by UEA have been assessed using the allocation procedure. By using the outputs from these climate models , the predicated movement of climate classes can be determined throughout Europe and at higher resolution for Great Britain. At the European scale, the greatest predicted changes in environmental diversity occur in Iberia and around the Mediterranean fringe. These areas show substantial decreases in the diversity of the region indicated by a fall in the number of classes present mainly due to the extension of two arid classes. The other major changes are in Northeast Europe where large uniform classes were sensitive to the scenarios but the implications are more difficult to determine. Using the half x half degree resolution, major changes can be seen in Great Britain with areas north and west of the Severn / Wash line becoming more oceanic where as those to the south and east becoming more continental. When the same scenarios are imposed in Great Britain using the 10 x 10 km resolution a new climate class was identified as being present whose distribution is centred in eastern Denmark. This is because the half by half degree cells smooth local variation. Two hyper-oceanic classes also extended to the east with implications biodiversity. The different scenarios show climate classes with continental affinities moving into Britain agreeing with other results from the TIGER programme. This ability to draw on classes from outside the immediate domain is an important feature of this classification when carrying out assessment at a local scale. Within Great Britain particular areas are seen to be sensitive to the predicted change when using the higher resolution e.g. the Cairngorm plateau is affected by the extension of oceanic classes. Such changes have important implications for vegetation, habitats and biodiversity. Isolated populations of plants at the edge of their distribution are likely to be affected by such changes because there are no refuges to retreat to. Further implications of the scenarios will be considered in conjunction with the recent empirical evidence of climate change. Further applications of the classification will also be discussed.