Agriculture Reference
In-Depth Information
B.P.Degens
Microbial Catabolic Evenness
5.1
Microbial Catabolic Evenness:
A Potential Integrative
Indicator of Organic Matter
Management?
B.P. D
EGENS
Ecosystems Research Group, Department of Botany,
The University of Western Australia,Nedlands, WA 6907, Australia
Introduction
The presence of an active and diverse microbial community in soil can be
considered a good indicator of a healthy and functioning soil ecosystem. In
contemporary ecology, diversity of higher organisms is commonly used as
an indicator of ecosystem health because this property of communities is
important for the maintenance and stability of ecosystem processes. How-
ever, for soil microbial communities, it has not been possible to measure
species diversity accurately (Giller
et al
., 1997; Trevors, 1998). The relative
diversity of functions performed by microbial communities is possibly more
ecologically relevant to soil processes than species diversity (Zak
et al.
,
1994; Trevers, 1998). Furthermore, in practical terms, it is the diversity of
soil functions that is of interest to farmers, agronomists and policy makers.
It is unlikely that the functional diversity of soil microbial communities can
be determined from species diversity (Giller
et al
., 1997; Degens, 1999).
However, a component of the functional diversity in soil communities can
be measured directly using a simple methodology (Degens and Harris,
1997; Degens
et al
., 2000b).
The implications of soil organic matter management for microbial
diversity are poorly understood. Depletion of organic matter in soils can
result primarily in loss of microbial nutrient cycling, water-holding capacity
and nutrient retention capacity (Gregorich
et al
., 1994). An understanding
of whether these changes have any effect on the diversity of microbial
communities or, more importantly, the functioning of these communities,
is necessary to evaluate long-term effects of land uses on soils.
Search WWH ::
Custom Search