Modeling the contributions of decomposer fungi in nutrient cycling

Title	Modeling the contributions of decomposer fungi in nutrient cycling
Publication Type	Book
Year of Publication	1992
Authors	Moorhead DL, Reynolds J.F
Series Editor	Carroll GC, Wicklow DT(eds.)
Series Title	The Fungal Community: Its Organization and Role in the Ecosystem
Edition	Second Edition
Number of Pages	691-714
Publisher	Marcel Dekker
City	Boston, Massachusetts
Accession Number	JRN00160
Call Number	00433
Keywords	book, books, chapter, chapters, decomposition,fungal, fungal decomposition, model,fungal decompostion, nutrient cycling,fungal decomposition, report, reports, simulation,fungal decomposition
Abstract	Natural and agricultural ecosystems contain complex fungal communities consisting of many species, interacting in many ways to help define the "character" of these systems. Saprotrophic fungi play key roles in nutrient cycling processes within these ecosystems...as they are the principal decomposers of recalcitrant compounds, e.g., lignocelluloses..., and compete with other heterotrophs and plants for energy and nutrients... Nevertheless, their precise roles in these processes remain unclear because making such assessments are difficult and relevant data are limited. How then, can we begin to elucidate their various roles and contributions? Three major fields of research provide us with a basis for addressing this question.... The first consists of observations and experimental research examining the physiological and autecological attributes of fungi. Most of this research focuses on individual species or pure cultures, although studies of the interactions between species are also available. A second field examines fungal growth processes, including the development of simulation models. These efforts include many levels of detail and, again, mostly focus on isolated species. The third area concerns decomposition processes and the construction of representative models, but rarely identify fungi as an independent component. Together, these three fields of research cover the basic concepts needed to initially describe the roles of saprophytic fungi in nutrient cycling processes. It remains to develop a complete conceptualization of this information. In cases such as these, mathematical models are valuable research tools that can help organize data into an overall synthesis. The process of developing a model tests our understanding of the system, identifies areas of uncertainty and, importantly, provides a means of examining alternative conceptual frameworks. The resulting model then serves as a "working hypothesis" that can be quantitatively as well as conceptually tested for validity. Many models have been constructed to simulate either decomposition processes or fungal growth dynamics, but as Paustian (1985) noted, a major conceptual gap exists between these two foci. The principal objectives of this chapter are to: 1) summarize background information relevant to modeling fungal contributions to nutrient cycling and 2) evaluate the few pioneering modeling studies that include both perspectives.