Grazing is a key regulator of the biodiversity of the desert steppe in Inner Mongolia and has important ecological significance for the sustainable development of underground ecosystems. In a 14-year grazing intensity experiment, we systematically explored the changes in soil nematode communities in desert steppe soils and comprehensively evaluated the optimal grazing intensity for the sustainability of the desert steppe underground ecosystem. Using high-throughput sequencing, we analyzed the soil nematode communities and their relationships with environmental factors. The 14-year grazing experiment revealed a significant impact on the diversity and composition of the soil nematode community in the surface layer (0–10 cm) and on the soil nematode community in the whole soil layer (0–20 cm). Based on LEfSe multilevel discriminant analysis, we found that the relative abundances of Acrobeles, Cephalobus, Filenchus, Aphelenchus, Longidorella, Amplimerlinius, Aporcelaimellus, Acrobeloides, Dorylaimellus, Hemicycliophora, Thonus, Alaimus, and Oxydirus changed significantly under different grazing treatments. Considering the number and function of soil nematode communities, long-term light grazing was found to significantly promote an increase in soil nematode diversity and helped maintain soil nematode community stability. We determined that the most suitable grazing intensity for the sustainability of the soil underground ecosystem of the desert steppe in Inner Mongolia is light grazing (0.91 sheep hm^-2 0.5 yr^-1). We have, thus, provided a tool for determining and evaluating optimal grazing intensities for sustainable soil underground ecosystems.

中文翻译：

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基于土壤线虫群落和功能的荒漠草原最佳放牧强度探索

放牧是内蒙古荒漠草原生物多样性的关键调节因子，对地下生态系统的可持续发展具有重要的生态意义。在为期 14 年的放牧强度试验中，我们系统地探索了荒漠草原土壤中土壤线虫群落的变化，并综合评估了荒漠草原地下生态系统可持续性的最佳放牧强度。使用高通量测序，我们分析了土壤线虫群落及其与环境因素的关系。14年的放牧实验表明，对表层（0-10 cm）土壤线虫群落和整个土壤层（0-20 cm）土壤线虫群落的多样性和组成有显着影响。基于 LEfSe 多级判别分析，Acrobeles , Cephalobus , Filenchus , Aphelenchus , Longidorella , Amplimerlinius , Aporcelaimellus , Acrobeloides , Dorylaimellus , Hemicycliophora , Thonus , Alaimus , and Oxydirus不同放牧处理下发生显着变化。考虑到土壤线虫群落的数量和功能，发现长期轻度放牧显着促进了土壤线虫多样性的增加，并有助于维持土壤线虫群落的稳定。我们确定内蒙古荒漠草原土壤地下生态系统可持续性最适宜的放牧强度为轻放牧（0.91 羊 hm ^-2 0.5 yr ^-1）。因此，我们提供了一种工具，用于确定和评估可持续土壤地下生态系统的最佳放牧强度。