Colonization-Competition Tradeoffs as a Mechanism Driving Successional Dynamics in Ectomycorrhizal Fungal Communities
- Author: mycolabadmin
- 2011-09-19
- View Source
Summary
This research examines how different species of beneficial fungi compete to form partnerships with pine tree roots, and how their competitive abilities change depending on their life stage. The findings help explain how fungal communities in forests change over time, similar to how different plant species succeed one another as forests mature. Impact on everyday life:
– Helps forest managers better understand and maintain healthy tree-fungal partnerships
– Provides insights for restoration of disturbed forest ecosystems
– Contributes to understanding how climate change might affect forest health through impacts on fungal communities
– Could inform development of better fungal inoculants for tree nurseries and reforestation efforts
Background
Ectomycorrhizal (ECM) fungi are dominant microorganisms in forest soils that play essential roles in plant growth, nutrient cycling, and food web dynamics. While patterns of succession in ECM communities have been documented, the mechanisms driving these changes are not well understood. One potential factor is a tradeoff between colonization ability (via spores) and competitive ability (via mycelium), which has been shown to be important in plant community succession.
Objective
To experimentally examine whether strong spore-based competitors remain dominant on plant root tips as competition shifts to mycelial-based interactions among three naturally co-occurring ECM species (Rhizopogon occidentalis, R. salebrosus, and Suillus pungens).
Results
In the microcosm experiment, a clear competitive hierarchy emerged with R. salebrosus > R. occidentalis > S. pungens. While competitive effects were also observed in culture assays, no similar hierarchy was present. The results contrasted with previous findings from spore-based competition, suggesting that ECM competitive outcomes can be life-stage dependent.
Conclusion
This study provides the first experimental evidence that ECM competitive abilities can be life-stage dependent and that changes in species abundance over successional time scales may result from tradeoffs between colonization and competitive ability. The findings suggest that interspecific competition plays a significant role in ECM interactions and may influence temporal patterns of ECM community structure.
- Published in:PLoS One,
- Study Type:Experimental Study,
- Source: 10.1371/journal.pone.0025126