[Nitrogen fixation potential of biological soil crusts in Heidaigou open coal mine, Inner Mongolia, China].

Nitrogen limitation is common in terrestrial ecosystems, and it is particularly severe in damaged ecosystems in arid regions. Biological soil crusts (BSCs) , as a crucial component of recovered vegetation, play a vital role in nitrogen fixation during the ecological restoration processes of damaged ecosystems in arid and semi-arid regions. In this study, two dominant types of BSCs (i.

[Species composition and population structure of plant communities on semi-fixed dunes of the Gurbantongut Desert, China.].

The objective of this study was to investigate species composition, and predict future development of dominant species on semi-fixed sand dunes in the Gurbantongut Desert. Using the plant height, crown area and volume instead of age structure, the growth and development condition of dominant shrub populations were analyzed. The results showed that totally 23 species were observed, of which Chenopodiaceae occurred the most with 6 genera 8 species, followed by Asteraceae with 5 genera 6 species.

[Effects of sand burial on fluxes of greenhouse gases from the soil covered by biocrust in an arid desert region.].

Based on the measurements of the fluxes of CO, CH and NO from the soil covered by two types of biocrusts dominated separately by moss and algae-lichen, followed by 0 (control), 1 (shallow) and 10 (deep) mm depths of sand burial treatments, we studied the effects of sand burial on greenhouse gases fluxes and their relationships with soil temperature and moisture at Shapotou, southeastern edge of the Tengger Desert. The results showed that sand burial had significantly positive effects on CO emission fluxes and CH uptake fluxes of the soil covered by the two types of biocrusts, but imposed differential effects on NO fluxes depending on the type of biocrust and the depth of burial. Deep burial (10 mm) dramatically increased the NO uptake fluxes of the soil co-vered by the two types of biocrusts, while shallow burial (1 mm) decreased the NO uptake flux of the soil co-vered by moss crust only and had no significant effects on NO uptake flux of the soil covered by algae-lichen crust.

[Nitrification of biological soil crusts and soil system during drought process and its response to temperature and moisture: A case study in the Shapotou region, Northwest China].

Two types of soil covered by biological soil crusts (BSCs) , i.e. moss and algae, and moving sand in the natural vegetation area at the southeast fringe of the Tengger Desert were collected intactly.

[Greenhouse gases fluxes of biological soil crusts and soil ecosystem in the artificial sand-fixing vegetation region in Shapotou area].

Uncertainties still existed for evaluating greenhouse gases fluxes (GHGs), including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) at the regional scale for desert ecosystem because available GHGs data about biological soil crusts (BSCs) was very scarce. In 2011 and 2012, soil ecosystem covered by various types of BSCs and BSCs at different succession stages in an artificial sand-fixing vegetation region established in various periods at southeast of the Shapotou area in Tengger Desert was selected to measure fluxes of CO2, CH4 and N2O using static chamber and gas chromatography. The results showed that curst type, recovery time and their interactions with sampling date significantly affected CO2 flux.