Goal functions, orientors and indicators (GoFOrIt's) in ecology. Application and functional aspects-Strengths and weaknesses

For more than two millenniums it has been almost impossible to address the issue of teleology in Western world science. Meanwhile, after the introduction of a systems view in ecology it has been clearly demonstrated that when attempting to understand nature as ecosystems, we deal with structures organized in a hierarchy and with a very high complexity. Many unexpected properties emerge from the constituent components and the interactions among them. The processes result in an intricate behaviour that can only be understood and explained within the realm of some degree of goal oriented behaviour of the systems. The use of the term goal function proper implies that a full teleological perspective is included in our perception of the systems. However, lately we have tended use more vague concepts like orientors and indicators. This paper argues that such a division makes sense, only we need in the future to be more clear and consistent in our use of the concepts. The term goal functions should be reserved to functions that are given final extremum states alone. Orientors should be used for localized directional behaviour in time and space. Indicators should be used where isolated time/space information exists. It may be used for monitoring changes in systems without giving any directional cause to development. The exact role among the concepts of being either a goal function, orientor or indicator is not always clearly defined. In many cases because the concepts are often used outside their original domains. Three types of original domains are clearly distinguishable, a biotic, a network and a thermodynamical direction. The strengths and weaknesses within the areas are discussed. Biotic concepts share the advantage of being close to established biological views and traditional ecology. They tell little about functionality, directionality and consequences of interactions. This is opposed to the two other directions that find their background in network analysis, information theory, and various domains of thermodynamics. As derived from physics the latter two areas achieve some scientific credibility, but suffer from problems of definition already inherent in the scientific sub-disciplines. Concerning the acceptance of ecosystem theory to ecologists it is also clear that approaches close to traditional biology such as the energetics of eco-physiology and diversity are much more accepted than any of the others leading to an overwhelming number of isolated and non-aggregated indices in the area of indicators. Indices that demand multidisciplinary insights such as goal functions and orientors are found to be less popular and deserve to receive much more attention in the future.