疏勒河上游不同退化类型冻土可培养细菌数量变化

发布时间：2018-01-29 04:39

本文关键词： 疏勒河上游冻土退化土壤微生物变化特征环境因素　出处：《生态学杂志》2017年10期 　论文类型：期刊论文

【摘要】：在气候变暖及人类活动的双重干扰下,疏勒河上游冻土发生了显著退化,具体表现为活动层厚度加大、植被退化等。然而,关于冻土退化对微生物的影响还未见报道。本文以疏勒河上游不同季节(4月、6月、9月)、不同退化程度冻土为对象,研究了可培养细菌数量的季节性变化及其影响因素。结果表明:研究区域可培养细菌数量介于0.4×10~7~5.3×10~7CFU·g~(-1),3个月份土壤可培养细菌数量均随冻土退化程度增加而显著下降,且同种类型冻土6月份样品中可培养细菌数量最多,但不同类型冻土细菌数量的季节变化未表现出一致的规律性。相关性分析表明,可培养细菌数量与土壤含水量、总氮呈极显著正相关,与有机碳呈显著正相关。这些结果表明,伴随着冻土退化而发生的地上植被逆向演替过程中,青藏高原不同类型冻土间已产生较大的环境异质性如土壤碳氮及含水量,进一步可能导致冻土微生物数量分异。研究结果为利用微生物综合评价青藏高原不同类型冻土的生态环境提供了数据基础。
[Abstract]:Due to the double interference of global warming and human activities, the frozen soil in the upper reaches of Shule River has undergone significant degradation, such as increasing the thickness of active layer and degenerating vegetation, etc. The effects of permafrost degradation on microbes have not been reported. In this paper, the different seasons (April, June, September) of the upper reaches of the Shule River are taken as the objects. The seasonal variation of culturable bacteria and its influencing factors were studied. The results showed that the number of culturable bacteria in the study area was between 0.4 脳 10 ~ (7) (5.3 脳 10 ~ (7) CFU 路g ~ (-1)). In three months, the number of culturable bacteria decreased significantly with the increase of the degree of frozen soil degradation, and in June, the number of culturable bacteria of the same type of frozen soil was the highest. The correlation analysis showed that the number of culturable bacteria was positively correlated with soil water content and total nitrogen content. These results indicate that the reverse succession of aboveground vegetation occurs with the degradation of permafrost. The environmental heterogeneity of different types of frozen soil in Qinghai-Xizang Plateau, such as soil carbon, nitrogen and water content, has been great. The results provide a data basis for the comprehensive evaluation of the ecological environment of different types of frozen soil in the Qinghai-Tibet Plateau.
【作者单位】：太原师范学院地理科学学院;中国科学院西北生态环境资源研究院内陆河流域生态水文重点实验室;中国科学院西北生态环境资源研究院沙漠与沙漠化重点实验室;中国科学院西北生态环境资源研究院甘肃省极端环境微生物资源与工程重点实验室;
【基金】：国家科技支撑计划项目(2014BAC05B02) 国家自然科学基金项目(31570498和31470544) 山西省面五青年基金项目(201701D221225)资助
【分类号】：S154.3
【正文快照】： 冻土是地球上最极端环境之一,是地质历史和气候变迁背景下受区域地理环境、地质构造、岩性、水文和植被特征等因素影响下形成的的客观地质体,作为冷气候的产物之一,冻土覆盖了全球超过20%的陆地表层,在地气间物质和能量交换过程中发挥着重要作用,被称为全球变化敏感带(Zhang e

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