Successful recruitment of species in arid sandy areas has a positive impact on community reconstruction, biodiversity and ecological restoration, especially annual herbaceous plants, which are crucial components of sandy ecosystems and community assembly in arid dunes. 

However, the relevant mechanisms for sand burial and biocrust promoting recruitment of annual herbs in degraded sandy ecosystems are still unknown. 

A research team from the Northwest Institute of Eco-Environment and Resources (NIEER) of the Chinese Academy of Sciences conducted a field survey to verify the presence of biocrust and sand burial jointly promoted the assembly of herbs in arid sandy desert. 

The study was published in Plant Soil on July 7. 

The researchers investigated relationships between the cover of sand burial, biocrust and species richness of the herbs to provide preliminary direct evidence to test their initial hypothesis that biocrust and sand burial jointly promote the recruitment and assembly of the annual herb community by increasing soil water and nutrient availabilities. 

They found that the formation and colonization of biocrust magnified the capture of dispersed herb seeds and simultaneously created better moisture and nutrient conditions for their growth, especially when sand burial disturbances occurred, which also provided suitable burial conditions and better water resources for seed germination and seedling growth of herbs. 

The annual herbs are more frequently found in sand-buried biocrust patches than in either biocrust or bare sand single patches in the Tengger Desert, indicating a novel restoration guideline to promote annual herb community assembly in an arid sandy desert area by creating the opportunity of co-occurrence of biocrust and sand burial. 

"Our study not only demonstrates the importance of co-occurrence of biocrust and sand burial in shaping plant community structure, but also provides a new technique for ecological restoration in arid sandy areas," said Prof. JIA Rongliang from NIEER, corresponding author of the study.