Dryland biocrusts study may help fight desertification

LANZHOU — Chinese scientists have recently uncovered the distribution pattern of dryland biocrusts, often described as the "skin" of the soil or a "carpet" that stabilizes sand, according to the Northwest Institute of Eco-environment and Resources (NIEER), the Chinese Academy of Sciences.

This study offers new insights into dryland biocrusts, paving the way for their application in desertification control and ecological restoration efforts, said Li Xinrong, a researcher from NIEER who led the study.

The study was jointly conducted by researchers from the NIEER and the Institute of Geographic Sciences and Natural Resources Research, also under the CAS.

Biocrusts are composed of nonvascular plants and photoautotrophs, such as lichens, mosses and cyanobacteria, as well as various heterotrophic microorganisms. They constitute the main soil surface cover in drylands and play an important role in ecological, hydrological and soil processes and biogeochemical cycles in the global drylands.

"Notably, they can also make it difficult for invasive alien species, reducing their chances of settlement and effectively protecting original dryland and desert ecosystems," Li explained.

"Biocrusts have different morphology and life history as compared to vascular plant communities. Our study theoretically explains the distribution pattern of biocrusts in drylands," he said.

The team of scientists adopted a research method that combines computational modeling with field investigation. They employed a probabilistic cellular automaton model, which simulated the dynamic changes of lichen and moss patches.

The researchers carried out the field observations of biocrusts across successional stages at the Shapotou Desert Research and Experiment Station in Northwest China's Ningxia Hui autonomous region.

They recorded the coverage, composition and patch size distribution of biocrusts by setting up line transects in artificial sand-fixing vegetation zones at different successional stages.

"Our results provide empirical evidence that biocrusts act as ecosystem engineers, forming self-organized spatial patterns," Li said.

The results demonstrate the capability of the biocrust communities to self-organize themselves to form distinct spatial patterns, holding implications for ecosystem functions and the resilience of dryland ecosystems.

"The study provides a new perspective for understanding the ecological roles of biocrusts at different stages of succession," Li added.

Based on their continuous study on dryland biocrusts, Li and his team are exploring other measures, such as cultivating artificial biocrusts, to prevent and control sand movement. Combining artificial biocrusts with mechanical sand barriers, such as grass grids, can create stable, effective sand-fixing layers.

"This new method offers greater stability, higher sand-fixing efficiency and easier implementation. Looking ahead, we will continue to deepen our research on dryland biocrusts and provide more practical solutions for the global fight against desertification," Li said.

Xinhua