a key role in biogeochemical cycles. For example, inherent 

 biological processes limit the maximum rate of photosynthetic 

 energy-conversion in plants. Often, however, neither the rate- 

 limiting step, nor magnitude of the rate-limiting process, is 

 experimentally defined by classical techniques. Additionally, many 

 organisms channel materials and energy through different pathways 

 or into wasteful (futile) cycles. Futile or inefficient cycles 

 lead to production of soil humus, refractory dissolved organic 

 compounds in the ocean, and, over geological time (in conjunction 

 with non-biologically mediated, geochemical processes) fossil fuel 

 repositories. An understanding of how organisms respond to 

 environmental changes by altering biochemical fluxes may eventually 

 allow reasonable and predictable models to be made involving 

 material and energy flux within major groups of organisms, and 

 ultimately, between them and their ecosystem. 



Understanding the molecular basis of inherent biological 

 limitations of energy and material fluxes has the following primary 

 goals: 



a) to improve our understanding of the mechanisms and 

 measurement of energy and material fluxes through food webs and the 

 measurement of the magnitude and proportions of materials that are 

 not recycled; and 



b) to use these mechanisms (and the ecosystem models derived 

 from them) to obtain information to determine how environmental or 

 global change would affect pathways and magnitudes of the fluxes to 

 the atmosphere and stored in non-reactive pools. 



An understanding of how these inherent limitations influence 

 the fluxes of materials and energy in natural ecosystems will 

 require extensive laboratory studies with individual organisms and 

 microbial consortia, as well as studies of field populations. 

 Several levels of study will be needed, many of which lend 

 themselves well to the application of molecular genetics, 

 geochemistry, biophysics, and biochemistry. It was recommended, in 

 general, that high priority be given to the isolation and 

 characterization of causative organisms and their study as 

 individuals and as active consortia. 



The ideal method for determining inherent metabolic activity 

 would have several key features. First, organisms would be 



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