黄土高原不同侵蚀类型区生物结皮固氮活性及对水热因子的响应

应用生态学报

黄土高原不同侵蚀类型区生物结皮固氮活性及对水热因子的响应

明姣^1,2,3,赵允格^1,2,许明祥^1,2**,杨丽娜^1,2,3,王爱国²

(¹中国科学院水土保持与生态环境研究中心/黄土高原土壤侵蚀与旱地农业国家重点实验室, 陕西杨凌 712100; ^2西北农林科技大学水土保持研究所, 陕西杨凌 712100; ³中国科学院大学, 北京 100039)

出版日期:2013-07-18 发布日期:2013-07-18

Biological soil crust nitrogenase activity and its responses to hydro-thermic factors in different erosion regions on the Loess Plateau, China.

MING Jiao^1,2,3, ZHAO Yun-ge^1,2, XU Ming-xiang^1,2, YANG Li-na^1,2,3, WANG Ai-guo²

(¹Institute of Soil and Water Conservation, Chinese Academy of Sciences/State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Yangling 712100, Shaanxi, China; ^2Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi, China; ^3University of Chinese Academy of Sciences, Beijing 100039, China)

Online:2013-07-18 Published:2013-07-18

摘要/Abstract

摘要：

在野外调查的基础上,采集不同侵蚀类型区内发育至稳定阶段的生物结皮,分析水分和温度变化对生物结皮固氮活性的影响.结果表明:水蚀区、水蚀风蚀交错区、风蚀区生物结皮固氮活性表现为水蚀区(127.7 μmol·m^-2·h^-1)>水蚀风蚀交错区(34.6 μmol·m^-2·h^-1)>风蚀区(6.0 μmol·m^-2·h^-1);3个侵蚀类型区生物结皮固氮的最适温度分别为35、25和15 ℃.在最适温度条件下,水蚀区及水蚀风蚀交错区生物结皮固氮活性在100%～40%田间持水量时差异不显著;风蚀区生物结皮固氮活性对水分变化较为敏感,当含水量降至80%田间持水量时固氮活性开始显著降低,降至20%田间持水量时,生物结皮固氮作用停止.3个侵蚀类型区生物结皮固氮活性及其对水分与温度变化响应的差异与不同侵蚀类型区的气候、环境及生物结皮物种组成有关.

Abstract: Based on field survey, the biological soil crusts at their stable development stage were collected from the water erosion region, water-wind erosion region, and wind erosion region on the Loess Plateau, aimed to study the effects of the variations of moisture and temperature on the crusts nitrogenase activity (NA). The NA of the crusts in the erosion regions decreased in the order of water erosion region (127.7 μmol·m^-2·h^-1) > water-wind erosion region (34.6 μmol·m^-2·h^-1) > wind erosion region (6.0 μmol·m^-2·h^-1), and the optimal temperature for the crust nitrogen fixation was 35 ℃, 25 ℃, and 15 ℃, respectively. At the optimal temperature and 100%-40% field water-holding capacity, the NA of the crusts from the water erosion and water-wind erosion regions had no significant difference. The NA of the crusts from the wind erosion region was more sensitive to the variation of moisture, showing a dramatic decline when the moisture decreased to 80% field water-holding capacity, and totally lost when the moisture decreased to 20% field water-holding capacity. The differences in the NA of the crusts from the three erosion regions and the responses of the NA to the variations of moisture and temperature were likely associated with the climate, environment, and the crust species composition.

明姣1,2,3,赵允格1,2,许明祥1,2**,杨丽娜1,2,3,王爱国2. 黄土高原不同侵蚀类型区生物结皮固氮活性及对水热因子的响应[J]. 应用生态学报.

MING Jiao1,2,3, ZHAO Yun-ge1,2, XU Ming-xiang1,2, YANG Li-na1,2,3, WANG Ai-guo2. Biological soil crust nitrogenase activity and its responses to hydro-thermic factors in different erosion regions on the Loess Plateau, China.[J]. Chinese Journal of Applied Ecology.