Effects of fencing on near-term ecosystem multifunctionality in a typical steppe in Inner Mongolia

Fencing has been extensively used for the restoration of grassland degraded by human disturbance. However, its effects on ecosystem functions and services are still controversial. Here, we evaluated the response of ecosystem multifunctionality (EMF) to 7 years of grazing exclusion based on ten individual functions, and compared grazing exclusion with two common practices (mowing and grazing) in a typical steppe in Inner Mongolia. Plant and microbial diversity and three edaphic factors (soil pH, moisture and temperature) were also investigated to explore the main drivers regulating EMF. Compared with continuous grazing, fencing improved EMF mainly by increasing soil nutrient contents, including soil organic carbon, ammonium nitrogen, nitrate nitrogen and available phosphorus. No significant differences were found between fencing and mowing for all ten individual functions and EMF. Plant and fungal diversity were comparable between fencing and grazing, but were lower than under mowing, and bacterial diversity was similar between all three management practices. Soil pH, moisture and temperature were also affected by fencing. Structural equation modeling showed that EMF was mainly driven by soil moisture in the fencing and mowing plots, but by plant and bacterial diversity in the grazing plots. Our results suggest that relative to grazing, fencing and mowing are both feasible strategies to enhance EMF, and that mowing may be more conducive to biodiversity conservation. This study demonstrates that, maintenance of soil moisture is critical for the restoration of EMF in Inner Mongolia’s typical steppe. A conceptual framework of individuated ecosystem functions and EMF responses to grassland management regimes and how biodiversity and soil abiotic factors affect EMF in typical Chinese steppe ecosystems. • Contrast with grazing, fencing improved EMF mainly through enhancing soil nutrient contents. • Fencing and mowing had comparable EMF, but mowing was preferable for biodiversity conservation. • EMF was regulated by edaphic factors in fencing and Mowing, but by biotic factors in grazing. • Maintenance of soil moisture is critical for the restoration of EMF.