Previous efforts, however, have either tended toward precise measurement of abiotic processes in ecosystems or have resulted in more or less narrative descriptions of ecosystem phenomena. Progress has been hampered by lack of empirical studies coupled to theory and by limitations in our mechanistic understanding of how organisms and environmental constraints interact to build ecosystems. A general theory of biotic-abiotic interactions in ecosystems is only likely to emerge over years of intensive study. Ecosystem Development Current thinking in ecology views plants and animals as occupying more or less static niches that define the basic resource requirements for each species. The principal mechanisms of feedback between organism and environment are conservation of energy and conservation of mater.
Organisms require free energy to grow and reproduce.
However, the ability of organisms to use available free energy depends on the availability of basic ecosystem nutrients such as carbon, nitrogen, and phosphorus. Thus, organismal processing and cycling of nutrients constrains the energy flows in ecosystems. In a broad sense, this new approach cuts at the heart of complex adaptive systems. In this respect, the conceptual model is not unlike an economy in which agents transform raw materials into products that then become resources for the next agent and so on. In the near term, the research will focus on how stoichiometric and allometric constraints interact to control the dynamic and evolutionary properties of ecosystems.