Ecological Aspects of Biomass Removal in the Localities Damaged by Air-Pollution

Abstract

Removal of above-ground biomass is connected with nutrient exclusion from the forest ecosystem. This aspect is essential mainly in the localities with damage of soil conditions, e.g in the air-polluted areas. Therefore, quantification of possible biomass removal must be based on knowledge of current soil conditions (especially forest floor) under forest stands. We illustrate this problem with the example of the forest stands of substitute tree species, which were established in the Czech Republic on the sites where the declining spruce monocultures could not be replaced by ecologically suitable tree species due to continual air pollution impact and damaged forest soils. One of the most heavily air-polluted areas since the 1960s of the last century is the Krusne hory Mts. (figure 1). The Krusne hory Mountains (synonym: The Ore Mts. or Erzgebirge) are located in Central Europe on the border between the Czech Republic and Saxony, Germany. These mountains are known as an area where air pollution has had a very severe impact (Sramek et al., 2008a). Sulphur dioxide, produced mainly by coal power plants and the chemical industry, caused extensive decline of forests in the upper part of the Krusne hory Mountains during the 1970s and 1980s. Therefore, some new tree species, considered to be more resistant to air pollution, substituted the declining spruce in these areas. The substitute tree species stands occupied in this place about 36% of forest land area, i.e. about 41 thousand hectares. The largest percentage of this area is covered with birch (Betula sp.) and blue spruce (Picea pungens Engelm.) or mixtures of these two species. The third species according to covered area is European larch (Larix decidua Mill.) with more than 6.5 thousand hectares of forest land in the Krusne hory Mts. Nowadays, substitute stands are due to air pollution decrease in good health condition and grow well. Consequently, they are now at the beginning of tree species conversion. and the questions are: Is it possible to remove aboveground biomass for chipping (with respect to their effects of forest environment, especially in these heavily disturbed localities)? Presented chapter focuses on the results from above-ground biomass investigation in the substitute stands of blue spruce, European larch and birch located in the Krusne hory Mts. Study was completed with the results of investigation of quantity and quality of forest-floor (humus) horizons and litter-fall under these stands. Possible nutrient loss after removal above-ground biomass for chipping is discussed.