Data from: Applying a dryland degradation framework for rangelands: the case of Mongolia

Livestock-caused rangeland degradation remains a major policy concern globally and the subject of widespread scientific study. This concern persists in part because it is difficult to isolate the effects of livestock from climate and other factors that influence ecosystem conditions. Further, degradation studies seldom use multiple plant and soil indicators linked to a clear definition of and ecologically-grounded framework for degradation assessment that distinguishes different levels of degradation. Here, we integrate two globally applicable rangeland degradation frameworks and apply them to a broad-scale empirical dataset for the country of Mongolia. We compare our assessment results with two other recent national rangeland degradation assessments in Mongolia to gauge consistency of findings across assessments and evaluate the utility of our framework. We measured livestock-use impacts across Mongolia’s major ecological zones: mountain and forest steppe, eastern steppe, steppe, and desert steppe. At 143 sites in 36 counties, we measured livestock-use and degradation indicators at increasing distances from livestock corrals in winter-grazed pastures. At each site, we measured multiple indicators linked to our degradation framework, including plant cover, standing biomass, palatability, species richness, forage quality, vegetation gaps and soil surface characteristics. Livestock use had no effect on soils, plant species richness or standing crop biomass in any ecological zone, but subtly affected plant cover and palatable plant abundance. Livestock effects were strongest in the steppe zone, moderate in the desert steppe and limited in the mountain/forest and eastern steppes. Our results aligned closely with those of two other recent country-wide assessments, suggesting that our framework may have widespread application. All three assessments found that very severe and irreversible degradation is rare in Mongolia (1-18% of land area), with most rangelands only slightly (33-53%) or moderately (25-40%) degraded. We conclude that very severe livestock-induced rangeland degradation is overstated in Mongolia. However, targeted rangeland restoration coupled with monitoring, adaptive management and stronger rangeland governance are needed to prevent further degradation where heavy grazing could cause irreversible change. Given the broad applicability of our degradation framework for Mongolia, we suggest it be tested for application in other temperate grasslands throughout Central Asia and North America.由牲畜活动引发的草原退化（rangeland degradation）仍是全球范围内政策层面的核心关切之一，亦是学界广泛关注的研究课题。该关切持续存在的部分原因在于，难以将牲畜活动的影响与气候及其他影响生态系统状态的因素区分开来。此外，现有草原退化相关研究极少采用结合明确退化定义与基于生态学原理的评估框架的多维度植物、土壤指标体系，且该框架应可区分不同等级的草原退化。本研究整合两套全球适用的草原退化评估框架，并将其应用于蒙古国的大尺度实证数据集。我们将本次评估结果与蒙古国另外两项近期全国性草原退化评估结果进行对比，以衡量不同评估间结论的一致性，并验证本研究框架的应用价值。研究团队在蒙古国四大主要生态区——山地森林草原、东部草原、典型草原与荒漠草原——内开展了牲畜活动影响的调查测量。研究人员在36个县的143个调查点位中，于冬季牧场内沿着距牲畜圈栏由近及远的梯度，测定了牲畜活动相关指标与退化指标。在每个调查点位，我们测定了与本研究退化评估框架相关的多项指标，涵盖植被盖度、现存生物量、适口性、物种丰富度、饲草品质、植被空隙度以及土壤表面特征。研究结果显示，在所有生态区内，牲畜活动对土壤、植物物种丰富度及现存生物量均无显著影响，但会轻微影响植被盖度与适口性植物的丰度。牲畜活动的影响在典型草原区最为显著，荒漠草原区表现中等，山地森林草原与东部草原区则较为有限。本次研究结果与另外两项近期全国性草原退化评估的结论高度吻合，表明本研究框架具备广泛的应用潜力。三项评估均发现，蒙古国境内极严重且不可逆的草原退化极为罕见（仅占国土面积的1%~18%），多数草原仅处于轻度（33%~53%）或中度（25%~40%）退化状态。据此我们得出结论：蒙古国由牲畜活动引发的极严重草原退化情况被高估了。不过，针对可能因过度放牧引发不可逆变化的区域，仍需开展针对性草原修复工作，并结合监测、适应性管理与更完善的草原治理机制，以防止退化进一步加剧。鉴于本研究的退化评估框架在蒙古国具备广泛适用性，我们建议在中亚及北美其他温带草原区域对该框架开展应用测试。