Ostroumov S.A. Trends in modernizing the fundamental concept of ecosystem: self-repairing, self-cleaning, self-reforming, energy-saving, and labile biomachinery. - Ecological Studies, Hazards, Solutions, 2007, v. 12, p. 24-29. http://scipeople.com/publication/99066/; There are various concepts of ecosystem (e.g., Tansley, 1935; Alimov, 2000; Wetzel, 2001). Some authors consider an ecosystem to be a kind of organism or superorganism. Other authors consider it as a mechanism with a structure formed by a certain pattern of transfer of energy and matter. There are many types of ecosystems and possibly all of the various types of definition and vision are adequate in one or another specific situation. Recently, we published our own definition of an ecosystem that seems to be useful in some situations (Ostroumov, 2002c). The goal of this paper is to re-visit the formulations of some of the fundamental concepts underlying the functional organization of ecosystems. As our experience was mainly with aquatic organisms, we plan to use mainly the empirical data of studies of aquatic ecosystems and organisms. We hope that some part of our analysis will be applicable to both aquatic and terrestrial ecosystems. Our analysis leads to the following vision of an ecosystem that seems to be applicable to some natural and artificial aquatic ecosystems: we propose to see some of the aquatic ecosystems as self-repairing, self-cleaning, self-reshaping, energy-saving, and labile biomachinery. To support and substantiate this view, we locate some evidence from both our studies and the literature (see Table 1 in the article). The following issues were analyzed in the article: 1. Superorganism, mechanism or biomachinery? 2. Rigid structure or labile entity? We consider the aquatic ecosystem as a labile entity because…< see in the full text of the paper> 3. Energy wasting or energy saving? We consider the aquatic ecosystem as an energy-saving entity because…< see in the full text of the paper> 4. Needing an external repair shop or self-repairing? The aquatic ecosystem as a self-repairing, self-cleaning entity because…< see in the full text of the paper> 5. Paradox of identity: constancy of self-reforming? The aquatic ecosystem as a self-reforming, self-reshaping entity because…< see in the full text of the paper> 6. Sum of elements or hi-technology? 7. A new concept of competitive symbiosis. 8. Entropy and ecological repair. We studied effects of some chemicals on … < see in the full text of the paper> We consider ecological repair in aquatic ecosystems as another example of anti-entropy processes in life systems. 9. Individual elements of ecosystems: independent species or groups of species? We developed a new concept of groups of species that we call ecological clusters (Ostroumov, 2004b). Ecological clusters are…< see in the full text of the paper> The article contribute to the evolution of ecology that is on the verge of revolution in conceptual terms, which is of importance in order to understand and use ecosystem services. Key words: innovations in ecology, ecosystem, fundamental concepts, ecotechnology, biosphere, ecological clusters, entropy, symbiosis, biomachinery, energy-saving, ecological repair, theoretical biology and ecology, superorganism, ecosystem services