Physical stress and diversity-productivity relationships: The role of positive interactions

AUTOR(ES)

Mulder, C. P. H.

FONTE

The National Academy of Sciences

RESUMO

If environmental stress provides conditions under which positive relationships between plant species richness and productivity become apparent, then species that seem functionally redundant under constant conditions may add to community functioning under variable conditions. Using naturally co-occurring mosses and liverworts, we constructed bryophyte communities to test relationships between species diversity (1, 2, 4, 8, 16, 24, or 32 species) and productivity under constant conditions and when exposed to experimental drought. We found no relationship between species richness and biomass under constant conditions. However, when communities were exposed to experimental drought, biomass increased with species richness. Responses of individual species demonstrated that facilitative interactions rather than sampling effects or niche complementarity best explained results—survivorship increased for almost all species, and those species least resistant to drought in monoculture had the greatest increase in biomass. Positive interactions may be an important but previously underemphasized mechanism linking high diversity to high productivity under stressful environmental conditions.

Documentos Relacionados

• Diversity–productivity relationships: Initial effects, long-term patterns, and underlying mechanisms
• Federal and academic relationships: the biomedical sciences 1974.
• Medical scientists and intimate relationships: translating the language of love
• Genome Relationships: The Grass Model in Current Research
• Trust and supplier-buyer relationships: an empirical analysis