Dynamics of vegetation and soil carbon and nitrogen accumulation over 26 years under controlled grazing in a desert shrubland

摘要: For decades, arid desert ecosystems in northwest China, covering one-fourth the country’s land surface, have experienced a rapid decline plant species diversity, productivity and soil carbon stock owing to degradation by overgrazing. In this study, community composition, diversity productivity, as well (C) nitrogen (N) stocks, were monitored over 26 years from 1981 2006 severely degraded Haloxylon ammodendron-dominated shrubland where livestock densities reduced 4–5 1–2 dry sheep equivalent ha-1. The objective was assess long-term grazing effects on vegetation C N accumulation dynamics. Results showed that reduction of pressure significantly increased cover, resulting primarily an increase livestock-preferred species. Controlled also led marked increases stocks top 30 cm soil. This strongly associated with richness, cover biomass production. Averaged years, accumulated at rates 89.9 g 8.4 m-2 year-1, respectively, but varied greatly different time periods. greatest regeneration occurred first 8 largest took place during 9–18, time-lag response changes vegetation. Our results provide insights into recovery patterns ecosystem components influence prolonged overgrazing disturbance cannot be inferred short-term study. findings are important for assessing resilience these livestock-disturbed developing more effective strategy management biome perspective.