Botany online 1996-2004. No further update, only historical document of botanical science!

Ecological Aspects, Ecosystems

"...Ecology studies the conditions of the organisms' existence, the dependence of their way of life on the organic and inorganic environment, their budget, the interactions between them and their parasites, enemies, friends, etc. The more perfect the organism itself is organized and the more he is adapted to a group of conditions of existence, the more valuable its comparative ecology will be in understanding its descent and the transformation of its direct ancestors." E. HAECKEL, 1894.

HAECKEL coined the term ecology, that is the teaching of nature's budget, already in 1866, but he cannot be regarded as the founder of this discipline, since ecological problems were discussed already in Antiquity. THEOPHRAST's works contain a vast variety of relevant examples. The history of agriculture shows, that success came only after the importance of the soil type and cultivation, the fertilizing, irrigation, the right time of sowing, and pest control had been recognized.

The three-course rotation is the prime example of an ecologically useful farming in the pre-industrial society.

Different approaches to the beginning of a structured ecological research existed. C. GESNER's observations of a vegetational belting in the mountains, the discoveries made in the times of the voyages of discovery that the vegetation in different in other parts of the world. A. v. HUMBOLDT (1769 - 1859) issued a small writing pointing the way after his expedition to South America (1795- 1803) in 1807. It is called

"Ideas about a Plant Geography".

It contains not only a description of the vegetation, but also a vast variety of physical and chemical readings, like radiation, refraction, geological data, temperature, humidity, etc. He mapped out the vegetation of the different levels of altitude at the Chimborazo, a 6003 m high volcano that was assumed to be the highest mountain of the world in the 19th century.

The transplantation experiments performed by G. BONNIER and A. KERNER v. MARILAUN that they performed during the second half of the 19th century show, that habitat-specific growth types exist. We discussed the results in detail in the topic evolution. This fact alone indicates already that evolution and ecology are tightly linked and cannot be delimited exactly. They are two sides of the same coin. Evolution concentrates on a change in the genetic information, while ecology focuses more on selection and the impact of environmental factors. We looked into the way single plants are influenced by physical and chemical factors as well as by symbionts and parasites in earlier chapters. Also, we discussed plant development as a reaction towards different parameters. Studies of this type are nowadays usually summarized under the term autecology or physioecology. The opposite of autecology is synecology. Synecology analyzes the relations between groups of organisms as well as the influences the most different factors (turn-over, productivity, nutrient cycles) have on whole biocenoses and their reactions. The behavior of the individuals or of the whole species is usually not considered.

© Peter v. Sengbusch - Impressum