RESPONSES OF IRISH VEGETATION TO FUTURE CLIMATE CHANGE

It is widely accepted that anthropogenically driven climate change is having a significant impact on the natural environment of Ireland and this will accelerate in the future. The changes have been attributed to increasing concentrations of greenhouse gases in the atmosphere, of which carbon dioxide (CO₂) is the main contributor. There is now increasing evidence that elevated CO₂ will directly alter the structure of plant communities although this will depend on the availability of major nutrients, particularly nitrogen. Changes in plant phenology will also occur as a result of warming, resulting in changed patterns of development of vegetation and in particular longer growing seasons for plants. Climate plays a pivotal role in determining the geographic distribution of plant species and climate 'envelopes' describe the potential range of climatic conditions over which species and ecosystems occur. As the climate changes these climate envelopes will move and, based on available evidence, the predicted change in climate is expected to have significant effects on the distribution of species and ecosystems. Modelling of climate envelope movements show that some of the key Irish habitats, particularly peatlands, are likely to be vulnerable and may be eliminated by climatic change predicted during the rest of this century.