Brilliant biocrusts

Biocrust – or biological soil crust – has hit the cover of New Phytologist. New Phytologist Editor Sasha Reed introduces an ecosystem you may not have heard much about.

The photograph shows a dryland landscape on the Colorado Plateau, USA. In the photograph you can see biological soil crust (the dark, bumpy soil in the foreground). Biocrusts are communities of cyanobacteria, lichens and mosses, found in dryland ecosystems worldwide. You can also see a cactus (bottom right), shrubs (centre), a tree (upper middle), and the red spires of rock that characterise this area. This photograph shows the diversity of organisms living together on the Colorado Plateau and the biological and structural differences that we can see even on a single patch of land.

A dryland ecosystem landscape, with vascular plants amidst dark, bumpy biological soil crusts in the foreground. Courtesy of Sasha Reed (US Geological Survey).

Biocrusts are communities of soil autotrophs, and associated heterotrophs, that play numerous important roles in dryland ecosystems worldwide. These include stabilising soils, altering soil fertility and hydrology, and helping to determine albedo and soil temperatures.

We wanted to consider where we are heading as a community trying to improve our understanding of how biocrusts will respond to change and what these changes will mean for the services provided by dryland ecosystems.

The photograph on the cover of New Phytologist 223:3 shows how biocrusts, vascular plants of many types (cactus, grasses, shrubs, a tree), and bedrock co-exist within a single system, in this and many other drylands. This functional diversity drives interesting interactions and patterns and makes understanding the system-level responses to change an exciting challenge. For me, the photograph highlights the many organisms that interact to determine ecosystem function, and the need for a more holistic understanding of how drylands respond to change.

Virtual issue Editorial: Reed, S. C., Delgado‐Baquerizo, M. and Ferrenberg, S. (2019) Biocrust science and global change. New Phytologist, 223:3: 1047-1051. doi: 10.1111/nph.15992

Sasha Reed

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