Vulnerability of Agricultural and Forestry Ecosystems

Climate change could produce positive or negative effects on agriculture depending on the region and the ways in which the climate changes. Northern and southern regions of Europe will be particularly sensitive and in some cases vulnerable to these changes. Agriculture in northern Europe is likely to benefit from both a warming and the direct effect of increasing CO2 concentration (Mela, 1996). The increased productivity will, however, be accompanied by an increased need for fertiliser and pesticide inputs with possible negative environmental effects, e.g. Sirotenko et al. (1997) showed an increase in the length of growing periods (15-22 days) and heat availability (460-560 °C) for agricultural crops in the Russian area that, however, in some arid regions might be partially offset by an reduction in soil moisture content in the warm season.

In southern Europe, climate changes are expected to produce limited benefit for agriculture, especially for summer crops. The combined increase in temperature and reduction in precipitation during summer may enhance the problem of water shortage. Moreover, the increases in climatic inter-annual variability and extreme events may also affect crop production. Thus, lower yield (shorter growing season, increase in water shortage, heat stress) and higher yield variability (increase in extreme events) is expected (Harrison et al., 2000). No areas may become completely unsuitable for agriculture. A reduction of suitable areas for traditional crops is however expected. This may be overcome by the introduction of new crops.

Particularly vulnerable regions throughout Europe are those areas where there is a large reliance on traditional farming systems and production of quality foods. Where such farming and production systems rely on favourable climatic conditions, climate change may cause large disruptions in the rural society. Farms with large investments in infrastructure, buildings, machinery, land, etc., may be more vulnerable to rapid changes and require long lead times in decision making, especially in converting from one farming system to another.

In the boreal region, the current forests are most vulnerable at the polar and alpine timberline, because the structure and tree species composition of forests may be modified with a loss in their value for conservation, recreation and landscaping and reindeer husbandry. At the same time, however, the timber producing capacity of these forests may increase substantially, thus providing more opportunities for forestry.

In the Atlantic region, the forests at the coastal areas on sandy soils with low water holding capacity (e.g. Denmark) may be vulnerable due to limited water supply during summer time and the risk of wind damage. The summer drought may also affect the forests in continental Europe, especially the homogenous Picea abies forests may suffer for enhancement of attacks of insects and fungi and increase the risk of forest fire.

The vulnerability of forests will be very high in the Mediterranean region. This is mainly due to the summer precipitation, which no longer supports the present forest cover. This negative effect will be further enhanced by increasing the fire risk.

0 0

Post a comment