Yin Ya Li, Wang Yu Qin, Li Shi Xiong, Liu Yan, Zhao Wen, Ma Yu Shou, Bao Gen Sheng
State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining 810016, China.
Academy of Animal and Veterinary Science, Qinghai University, Xining 810016, China.
Ying Yong Sheng Tai Xue Bao. 2019 Jan 20;30(1):127-136. doi: 10.13287/j.1001-9332.201901.009.
Enclosing is an effective rehabilitation measure for degraded pastures that mimics natural recovery of vegetation. To examine the interaction between biotic and abiotic in lightly degraded and enclosing grasslands is helpful for a clear understanding of the structure and function of grassland ecosystem. In this study, soil microbial community and soil stoichiometric characteristics in lightly degraded and 10-year enclosing alpine meadows were studied by high-throughput sequencing and Biolog-Eco methods. The results showed that compared with lightly degraded grassland, the concentration of soil NH-N in the enclosing grassland increased significantly, while total K (TK) dramatically decreased. There was no obvious variation in soil total organic carbon (TOC), total N (TN), total P (TP), NO-N, available P (AP), available K (AK), microbial biomass C (MBC) and microbial biomass N (MBN). The soil microbial biomass C/N was significantly enhanced. The carbon metabolic capabilities of soil microbes in different soil layers of alpine mea-dow were obviously increased with the prolonged incubation time, but there was no significant difference between lightly degraded and enclosed meadows. The OTUs of soil bacteria was significantly higher than that of fungi in alpine meadow. The microbial similarity between lightly degraded and fencing grasslands was 27.0%-32.7%. Enclosing significantly increased the fungal relative richness of Ascomycota, Zygomycetes and Chytridiomycota, while simultaneously decreased the rela-tive abundance of Basidiomycetes. Compared with lightly degraded meadow, the bacterial relative richness of Acidobacteria significantly decreased in enclosing meadow. The community composition of soil fungi and bacteria greatly varied among different soil layers. There was significant difference of fungal community composition in the upper soils between lightly degraded and enclosed grassland. The soil bacterial community diversity was greatly affected by soil TN and AK, while the fungal community diversity was significantly affected by plant aboveground biomass. Soil AK produced great influence on soil microbial carbon source utilization capacity. Generally, long-term grazing exclosure had no significant effects on soil nutrients and soil microbial community diversity of lightly degraded grassland and thus would waste the pasture resources, whereas appropriate grazing could maintain the sustainable utilization of grassland.
封育是一种针对退化牧场的有效恢复措施,它模拟了植被的自然恢复过程。研究轻度退化和封育草地中生物与非生物之间的相互作用,有助于清晰理解草地生态系统的结构和功能。本研究采用高通量测序和Biolog-Eco方法,对轻度退化和封育10年的高寒草甸土壤微生物群落及土壤化学计量特征进行了研究。结果表明,与轻度退化草地相比,封育草地土壤铵态氮(NH₄⁺-N)浓度显著增加,而全钾(TK)显著降低。土壤总有机碳(TOC)、全氮(TN)、全磷(TP)、硝态氮(NO₃⁻-N)、有效磷(AP)、速效钾(AK)、微生物生物量碳(MBC)和微生物生物量氮(MBN)无明显变化。土壤微生物生物量碳氮比显著提高。高寒草甸不同土层土壤微生物的碳代谢能力随培养时间延长明显增强,但轻度退化草地与封育草地之间无显著差异。高寒草甸土壤细菌的操作分类单元(OTUs)显著高于真菌。轻度退化草地与围栏草地的微生物相似性为27.0% - 32.7%。封育显著增加了子囊菌门、接合菌门和壶菌门真菌的相对丰度,同时降低了担子菌门的相对丰度。与轻度退化草甸相比,封育草甸中酸杆菌门细菌的相对丰度显著降低。土壤真菌和细菌的群落组成在不同土层间差异很大。轻度退化草地与封育草地表层土壤真菌群落组成存在显著差异。土壤细菌群落多样性受土壤TN和AK影响较大,而真菌群落多样性受植物地上生物量影响显著。土壤AK对土壤微生物碳源利用能力影响较大。总体而言,长期禁牧对轻度退化草地土壤养分和土壤微生物群落多样性无显著影响,会造成牧场资源浪费,而适度放牧可维持草地的可持续利用。