3.4 Changes in the Biodiversity of Forest Ecosystems as Indicators of Ecological Adaptation
Falencka-Jablonska Malgorzata
The importance of the forest for the environment is today the determining factor in forest management and forest enterprise planning. The biodiversity of forest ecosystems is greatly influenced by their functions and structures and also by internal and external factors such as climatic conditions and silvicultural treatment. It must however be pointed out that there is no direct connection between these factors and biodiversity. Biodiversity may be considered from three different viewpoints:
1. species composition 2. genetical composition 3. ecosystems
Given the aim of maintaining biodiversity, the concept termed eco-development, in harmony with the rules of nature, has been elaborated. The manifold ecosystems occurring in Poland greatly facilitate the conservation of biodiversity. The distribution limits of many flora and fauna species run through Poland. Those of the flora include 40% of the higher plants occurring there, while those of the fauna include 96 different species of land
dwelling vertebrates, 30% of the mammals, 16% of the bird species, 22% of the reptiles and 28% of the amphibians to be found in Poland. According to ANDRZEJEWSKI and WEIGL E (1993), Poland possesses one of the highest ranges of biodiversity characteristic for the lowlands of Europe, especially as regards bog and forest biotopes.
Within Europe, Poland ranks fifth in terms of forest area, after Sweden, Finland, Spain and France. At the same time, its forest area (24.6% ) lies below the mean for Europe and is dominated by conifers (78% ). It is predicted that 30% of the surface area of Poland will be covered by forest by 2010 A.O. Inventories of the state of health of the forest have shown that 40% of the trees surveyed exhibit a reduction of photosynthetic organs. NOWICKI (1993) estimates the loss at 11-25%. The sulphur content of pine needles from the industrial area of upper Gllesia and the south-western part of Poland reaches a maximum of 18% . When comparing the mutual dependence of biodiversity and the factors influencing it with methods of forest management, the following criteria must be taken into account:
1. flora 2. fauna
3. plant pathogens (fungi).
One of the main factors influencing the biodiversity of forest ecosystems is air pollution;
within Poland this varies from region to region. The lowest values for SO2 and NOx are to be found in the north-east, moderate values in central Poland, and the highest in the industrial centres of upper Gllesia and the copper-smelting area of lower Gllesia (Legnica, Glogow).
If the characteristics and tempo of changes in biodiversity are to be investigated, over 75% of the forest stands in Poland must be surveyed, with special attention to harvesting, afforestation and selective utilisation. The aim of such an inventory should be to establish how the forest is adapting to changes in the environment. An analysis of biodiversity
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would play a determining role in future forest health inventories in Poland, and, in the long run, furnish a basis for the planning of a national forest management strategy.
3.4.1 References
ANDRZEJEWSKI, R.; W AIGLE, A. , red., 1993: Polskie studium rofoorodnosci biologicznej.
Warszawa, Narodowa Fundacja Ochrony Srodowiska, UNEP.
NOWICKI, M., 1993: Strategia ekorozwoju polski. Warszawa, Ministerstwo Ochrony Srodowiska, Zasobow Naturalnych i Lesnictwa.
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