『Abstract
Well-constrained carbon:nitrogen:phosphorus (C:N:P) ratios in
planktonic biomass, and their importance in advancing our understanding
of biological processes and nutrient cycling in marine ecosystems,
has motivated ecologists to search for similar patterns in terrestrial
ecosystems. Recent analyses indicate the existence of “Redfield-like”
ratios in plants, and such data may provide insight into the nature
of nutrient limitation in terrestrial ecosystems. We searched
for analogous patterns in the soil and the soil microbial biomass
by conducting a review of the literature. although soil is characterized
by high biological diversity, structural complexity and spatial
heterogeneity, we found remarkably consistent C:N:P ratios in
both total soil pools and the soil microbial biomass. Our analysis
indicates that, similar to marine phytoplankton, element concentrations
of individual phylogenetic groups within the soil microbial community
may vary, but on average, atomic C:N:P ratios in both the soil
(186:13:1) and the soil microbial biomass (60:7:1) are well-constrained
at the global scale. We did see significant variation in soil
and microbial element ratios between vegetation types (i.e., forest
versus grassland),but in most cases, the similarities in soil
and microbial element ratios among sites and across large scales
were more apparent than the differences. Consistent microbial
biomass element ratios, combined with data linking specific patterns
of microbial element stoichiometry with direct evidence of microbial
nutrient limitation, suggest that measuring the proportions of
C, N and P in the microbial biomass may represent another useful
tool for assessing nutrient limitation of ecosystem processes
in terrestrial ecosystems.
Keywords: Carbon; Microbial biomass; Nitrogen; Phosphorus; Soil;
Stoichiometry
The environment not only determines the conditions under which
life exists, but the organisms influence the conditions prevailing
in the environment.−Alfred Redfield (1958)』
Introduction
Methods
Literature review
Quantifying soil microbial biomass: the chloroform fumigation
and extraction (FE) technique
Data analyses
Results and discussion
Total soil C:N:P ratios
C:N:P ratios in the soil microbial biomass
Relationships between soil and microbial element ratios
Do Redfield-like ratios exist for the soil microbial biomass?
Soil microbial biomass element ratios as indices of nutrient
limitation
Acknowledgments
Appendix
References