Wang Lixin, Liu Huamin, Liu Yuhong, Li Jianwei, Shao Hongbo, Wang Wei, Liang Cunzhu
College of Environment and Resources, Inner Mongolia University, Hohhot 010021, China.
College of Life Sciences, Inner Mongolia University, Hohhot 010021, China.
ScientificWorldJournal. 2014;2014:765907. doi: 10.1155/2014/765907. Epub 2014 May 19.
In recent decades, degradation of ecosystem in the steppe region of the Inner Mongolia Plateau, especially in riparian floodplain wetlands, has become a significant ecological crisis. Not uncommonly, with the increasing of livestock in the Inner Mongolian steppe region, a riparian floodplain wetland is becoming a hotspot area of grazing for local herdsmen. Hence, it is essential to understand degradation mechanisms of riparian floodplain wetland ecosystems caused by extensive grazing. In this study, the spatial distribution of soil compaction, salinity, total nitrogen, total phosphorus, organic carbon, and microbial biomass C and N were investigated. The results showed that grazing led to an increase in soil compaction and soil surface salinity, which significantly lowered levels of total N, P, and TOC in the soil surface. Grazing decreased soil microbial biomass C and N concentration in the lower riparian floodplain wetland, whereas it significantly increased soil microbial biomass C and N concentration in the higher riparian floodplain wetland. Elevation differences in the riparian floodplain wetland increased spatial heterogeneity in the soil and thus resulted in different influence of grazing on wetland soils and ecosystem. Therefore, elevation differences and grazing intensity were the main factors controlling soil characteristics in the riparian floodplain wetland of this region.
近几十年来，内蒙古高原草原地区，尤其是河岸漫滩湿地的生态系统退化已成为一个重大的生态危机。在内蒙古草原地区，随着牲畜数量的增加，河岸漫滩湿地成为当地牧民放牧的热点地区，这种情况并不罕见。因此，了解过度放牧导致的河岸漫滩湿地生态系统退化机制至关重要。在本研究中，对土壤压实度、盐分、总氮、总磷、有机碳以及微生物生物量碳和氮的空间分布进行了调查。结果表明，放牧导致土壤压实度和土壤表面盐分增加，显著降低了土壤表层的总氮、总磷和总有机碳水平。放牧降低了下游河岸漫滩湿地土壤微生物生物量碳和氮的浓度，而在较高的河岸漫滩湿地，放牧显著增加了土壤微生物生物量碳和氮的浓度。河岸漫滩湿地的海拔差异增加了土壤的空间异质性，从而导致放牧对湿地土壤和生态系统的影响不同。因此，海拔差异和放牧强度是控制该地区河岸漫滩湿地土壤特性的主要因素。
