Ueber einige fortschritte der kausalen Vegetationskunde

On non-linear species response models in ordination

“…A number of types of ecological response curves can be recognized from descriptive field studies ranging from symmetric bell-shaped curves through skewed curves to bimodal curves with marked asymmetry in the peaks (see Mueller-Dombois & Ellenberg 1974). There is experimental evidence to support these curves (Ellenberg 1954, Mueller-Dombois & Sims 1966. These particular studies present an explicit statement that competition may be responsible for variations in response curves.…”

“…Ellenberg (1954, see also Mueller-Dombois & Ellenberg 1974) has advanced the idea that while the physiological response of a species may be bell-shaped, the ecological response curve under natural conditions including competition (interference) from other species, may be different. A number of types of ecological response curves can be recognized from descriptive field studies ranging from symmetric bell-shaped curves through skewed curves to bimodal curves with marked asymmetry in the peaks (see Mueller-Dombois & Ellenberg 1974).…”

Botanical diversity in British mires

“…Although there are few critical data available it seems likely that many fen plants may not have a direct requirement for high water tables: even some 'wet fen' species can tolerate occasional droughts (Gurney, 1922); most fen phanaerophytes can be grown readily in garden conditions without supplementary watering; and some typical fen plants sometimes grow naturally in dry situations (for example, Epipactis palustris, which is most usually associated with spring-fed sites with a consistently high water table also grows, as a small population, on the top of a sun-baked chalk down in Wiltshire (Grose, 1957). It thus seems probable that the restriction of some fen plants to waterlogged sites may be more due to their competitive exclusion from drier sites (Ellenberg, 1954) than to a specific requirement for wet conditions. The lack of a detailed understanding of the water level requirements of fen plant species makes it difficult to predict the effects of partial drainage on fen ecosystems.…”

Permanent quadrats: An interface for theory and practice

“…(b) Synthesis, where species are combined to form a specific assemblage whose behaviour is then studied. Ellenberg (1953Ellenberg ( , 1954 provides one of the best examples of such an experimental analysis along a depth-to-watertable gradient, but the dynamic aspects are limited to only two years (Ellenberg, 1954). McCormick et al (1974) provide another example with a welldefined ecosystem in depressions on granite outcrops with limited numbers of terrestrial plant species which can be studied.…”