Understanding the nutrient conditions and changes of biological soil crusts (BSCs) over a successional chronosequence of revegetation may deepen our understanding of the role that BSCs play in the biogeochemical cycles and desert restoration. 

However, previous studies have analyzed changes in soil physical properties, diversity and activity of microbial communities and vegetation composition of the successional chronosequence of revegetation, but changes in elemental concentrations of BSCs have not been previously reported. 

Recently, a research group from Northwest Institute of Eco-Environment and Resources (NIEER) of the Chinese Academy of Sciences examined permanent experimental sites with sand-binding revegetation of different ages in the Shapotou region of the Tengger Desert and analyzed the nutrient enrichment of BSCs and soils. 

Scientists investigated the elemental levels of K, Na, Ca, Mg, Mn, Zn, Cu, and Fe in surface soil covered by cyanobacteria-lichen crusts, moss crusts and subsoil. Nutrient enrichment of BSCs and soils were analyzed to reflect the nutrient changes in the revegetated desert ecosystem.  

The study result indicated that concentrations of K, Na, Ca, Mn, Zn, and Cu in cyanobacteria-lichen crusts are significantly higher than in mobile sand dunes. 

Furthermore, scientists found that the changes in nutrient enrichment rate (except for Na) showed a unimodal pattern and that year 31 was a key turning point after which the rate switched from increasing to decreasing over time. 

The long-term study indicates that both cyanobacteria-lichen crusts and moss crusts can effectively improve nutrient accumulation and promote edaphic conditions, which is beneficial to the development and nutrient cycling of desert ecosystem. 

This study aims to shed light on the changes of elemental concentrations and their enrichment in fixed surface soil of sand dunes over a 50-year revegetation chronosequence linked to BSCs of different successional stages in the Tengger desert of China. 

Moreover, this study provides a first-hand knowledge for better management of desert ecosystems occupied by BSCs and accurate identification of the nutrient conditions of revegetated ecosystems in arid regions. 

The study entitled “Biological soil crusts enhance the recovery of nutrient levels of surface dune soil in arid desert regions” was published in Ecological Indicators. 

Contact: 

HE Mingzhu 

E-mail: hmzecology@lzb.ac.cn 

Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.