Balance between facilitation and resource competition determines biomass-density relationships in plant populations
Authored by Sa Xiao, Gang Wang, Jacob Weiner, Fernando T Maestre, Cheng-Jin Chu, You-Shi Wang, Zheng-Hu Duan
Date Published: 2008
DOI: 10.1111/j.1461-0248.2008.01228.x
Sponsors:
Chinese National Natural Science Foundation
United States National Science Foundation (NSF)
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Model Code URLs:
Model code not found
Abstract
Theories based on competition for resources predict a monotonic negative
relationship between population density and individual biomass in plant
populations. They do not consider the role of facilitative interactions, which are known to be important in high stress environments. Using an
individual-based `zone-of-influence' model, we investigated the
hypothesis that the balance between facilitative and competitive
interactions determines biomass-density relationships. We tested model
predictions with a field experiment on the clonal grass Elymus nutans in
an alpine meadow. In the model, the relationship between mean individual
biomass and density shifted from monotonic to humped as abiotic stress
increased. The model results were supported by the field experiment, in
which the greatest individual and population biomass were found at
intermediate densities in a high-stress alpine habitat. Our results show
that facilitation can affect biomass-density relationships.
Tags
Dependence
Metaanalysis
Communities
Body-size
Symmetry
Increase
Abiotic stress
Positive interactions
Stress-gradient hypothesis
Arid environments