A substitute society is the term used for plant societies that have arisen under anthropogenic influences, are preserved or are a direct result of current or former uses. The term surrogate society refers to the concept of potential natural vegetation and is used only in this context.
Replacement society and potential natural vegetation
The potential natural vegetation is a theoretical concept for assessing the natural site potential. It is used to find out what type of vegetation could be found in a particular location instead of the existing vegetation if the conditions are changed. This allows z. For example, the suitable tree species can be selected for reforestation, or the state of vegetation after a change in use or abandonment can be forecast.
To determine the substitute companies, the real vegetation of the location to be assessed is first recorded. A so-called closing company can be determined from this. This is the most permanent plant community that is possible at the respective location. If there were no human influences, one can assume that this vegetation would actually be found at this location. The closing company therefore corresponds to the potential natural vegetation in the true sense. Under the conditions of Central Europe, closing companies are almost exclusively forest companies. All other vegetation units are therefore substitute societies, e.g. B. coniferous forests, meadows, fields, grasslands. Since only the spontaneous plant cover is directly caused by the location factors, naturally only these can be used for the assessment. For the substitute society of a field, the weed flora is assessed accordingly, not the rape or rye sown by humans. For the replacement company of a coniferous forest, the ground vegetation, not the planted pines or Douglas firs. For the respective closing company, a range of possible substitute societies can be determined, which arise under certain human influences (e.g. the closing society oak-hornbeam-forest can have substitute societies among other oat-meadow, ryegrass-white clover-willow and arable-weed society correspond).
Due to human influences, especially usage influences, the real vegetation deviates in very many cases from the expected final society. Such a vegetation stock, which is subject to the same location influences (soil factors, local climate) as the final company, but bears different vegetation due to the usage factors, is a substitute society. Accordingly, there are as many substitute societies at a location as there are human usage influences.
Human influences, but also natural succession , can of course change not only the vegetation cover, but also the location. For example, soil that is exposed after deforestation can lose its humus cover (or the entire topsoil) due to erosion. Soils can be added or removed by excavators and construction machinery. Swamps can be drained by dykes and drainage ditches. Since this changes the potential of the location itself, the resulting vegetation stands are not regarded as substitute societies on the original location. Of course, they have their own closing company (which corresponds to the new location potential) and their own range of replacement companies.
Substitute societies are divided into levels of anthropogenic influence ( hemerobia ). This can explain syndynamic relationships between plant communities (e.g. progressive and regressive succession). Tüxen has divided the substitute societies into four degrees of increasing anthropogenic transformation, so that a substitute society of the first degree is closer to the potential final society in terms of plant sociology and syndrome than a substitute society of the fourth degree. In the scientifically descriptive sense, there is no rating associated with this classification, so that closing societies and substitute societies are to be viewed as different but equal plant societies that can thrive in one place of growth. But since substitute societies are in the economic context of land management, they can be assigned secondary value.
Substitute society and climax vegetation
In connection with the concept of potential natural vegetation, the hypothetical final state of vegetation development is called the closing society. In another theoretical context, this final state is understood as climax vegetation . The climax vegetation is the imagined final state of a natural development ( succession ) at a certain location, but taking into account the changes in location that take place. For example, on a poor raw floor, the final company will be a frugal and light pine forest. In the event of a succession in this location, the forest will change the soil, it can accumulate humus that stores water and nutrients and thus develop into an oak or beech forest. The concept of climax vegetation is criticized in this context for the fact that the result of the prognosis is even more hypothetical than the assignment of a final society due to the need to predict such changes. Within the sociological progression, climax vegetation is considered to be the 'most highly developed' form of vegetation in one location. The climax theory is therefore criticized for the fact that it implies a valuation that ultimately places the closing company over the substitute companies.
- Reinhold Tüxen: Today's potential natural vegetation as an object of vegetation mapping. In: Applied Plant Sociology 13, 1956. pp. 2-42.
- Otti Wilmanns: Ecological Plant Sociology. Heidelberg 1989.
- R. Tüxen: Today's potential natural vegetation as an object of vegetation mapping. O. Wilmanns: Ecological Plant Sociology: p. 41 f.
- H. Ellenberg: Vegetation of Central Europe with the Alps in an ecological, dynamic and historical perspective. Stuttgart 1996. M. Schaefer: Dictionary of Ecology. Heidelberg, Berlin 2003.
- I. Kowarik: On the human influence on flora and vegetation. Theoretical concepts and a quantification approach using the example of Berlin (West). Berlin 1988.
- A. Haß: The Monoclimax Theory as a Mirror of Conservative Subject Philosophy. In: Conservation and Democracy. Munich 2006.