Fungal communities and forest degradation

The change of land-use, e.g. deforestation, is one of the greatest threats to biodiversity worldwide, particularly within tropical ecosystems. There are quite a few projections out there that aim to predict extinction rates  in relation to climate change. However, such estimated extinction risks might be higher than projected if future potential locations of suitable climate do not coincide with other essential resources such as soil type or food resources. 

One aspect that is still poorly understood is the response of soil fungal communities to land-use change. Fungal communities are known to be affected by nutrient availability and plant species composition which suggests that any alteration to these factors by a change in land-use could result in a shift of soil fungal communities which in turn might have strong effects on the affected ecosystem.

Understanding the interactions among microbial communities, plant communities and soil properties following deforestation could provide insights into the long-term effects of land-use change on ecosystem functions, and may help identify approaches that promote the recovery of degraded sites.

An international team used a combination of next generation sequencing of the fungal barcode region ITS1 and the chloroplast trnL intron region for plant roots to estimate fungal and plant community composition in soil sampled across a chronosequence of deforestation in the Brazilian Amazon rainforest.

They found that changes in fungal community composition were more correlated to plant community composition than to changes in nutrient availability or geographic distance. This means that knowledge of an ecosystems's plant community composition is a better predictor of microbial community composition than e.g. soil chemistry. 

Modern DNA Barcoding technologies allowed the authors to do community analysis on a scale that was previously not possible and they a quick to point out:

A clearer understanding of interactions between plant and fungal communities could prove useful to conservation and restoration biology, as it could identify management strategies that better promote both reforestation and the recovery of microbially mediated ecosystem functions in degraded areas.