Efficient vegetation restoration in Mu Us desert reduces microbial diversity due to the transformation of nutrient requirements

Abstract

Various nutrient requirements of soil microorganisms often occur in restoration ecosystems, but the responses of microbial communities in different vegetation types remain unclear. In this study, we selected four types of vegetation (grassland desert (GD), desert steppe (DS), typical steppe (TS), and artificial forest (AF)) on the Mu Us Desert, and examined the soil physicochemical properties, extracellular enzyme activities (carbon (C)-, nitrogen (N)-, and phosphorus (P)-acquisition enzymes), and community characteristics. Our results revealed that the N-requirement of microorganisms in the area was higher than that of other elements, particularly when organic C was scarce, whereas severe P requirement was detected in the presence of abundant organic matter. Compared with TS, we detected a higher diversity of microorganisms in GD, DS, and AF, and the microbial communities were dominated by a few taxa with loose internal connections and higher C and N requirements. Stronger N and P requirements reduced the diversity of microorganisms and the relative abundance of dominant taxa in TS, but increased the stability of bacterial communities. Our results further indicate that bacteria play a more active role in coping with the transformation of nutrient requirements. When C- and N-requirements of microorganisms were transformed to N and P, the abundance of dominant and sub-dominant taxa decreased and increased, respectively. Collectively, the results of this study indicate that efficient vegetation restoration in desert areas may lead to stronger nutrient requirements for microorganisms, thus reducing the diversity of microorganisms and causing unpredictable consequences for ecological sustainable development.

Keywords

• Extracellular enzyme activity
• Vegetation types
• Microbial N
• P requeriments
• Microbial community characteristics
• Vegetation restoration