干旱区生态环境知识资源中心(Arid): 内蒙古不同类型草地土壤氮矿化及其温度敏感性

Arid

	内蒙古不同类型草地土壤氮矿化及其温度敏感性
其他题名	Soil nitrogen mineralization and associated temperature sensitivity of different Inner Mongolian grasslands
	朱剑兴 1; 王秋凤 1; 何念鹏 1; 王若梦 1; 代景忠 2
来源期刊	生态学报
ISSN	1000-0933
出版年	2013
卷号	33 期号:19 页码:6320-6327
中文摘要	土壤氮矿化(Nitrogen mineralization)是土壤氮循环的重要环节，对土壤氮素供应以及植物生产力的维持具有十分重要的意义。沿中国东北草地样带(Northeastern China Transect， NECT)分别在典型草地、过渡草地及荒漠草地设置了3个实验样地，利用不同温度(5、10、15、20 ℃和25 ℃)和不同水分(30%、60%和90%土壤饱和含水量，Saturated soil moisture， SSM)的室内培养途径，探讨了不同类型草地的土壤氮矿化速率、土壤氮矿化的温度敏感性(Q_(10))及其主要影响因素。实验结果表明:从典型草地至荒漠草地，土壤全碳、全氮、全磷、微生物生物量碳氮含量均表现为逐渐下降的趋势;类似地，土壤净氮矿化速率、硝化速率也逐渐降低。在20 ℃和60% SSM时，土壤净氮矿化速率表现为典型草地(0.715 mg N kg~(-1) d~(-1)) > 过渡草地(0.507 mg N kg~(-1) d~(-1)) > 荒漠草地(0.134 mg N kg~(-1) d~(-1));相反，温度敏感性却逐渐升高，温度敏感性与基质质量指数呈负相关。草地类型和水分对于土壤净氮矿化速率、硝化速率具有显著影响，且二者间具有显著的交互效应。包含温度和水分的双因素模型可很好地拟合土壤氮矿化速率的变化趋势(P < 0.0001)，二者可共同解释土壤硝化速率92%-96%的变异。土壤氮矿化沿着草地演替呈现出很好的空间格局、并与温度和水分具有密切关系，为解释内蒙古草地空间分布格局提供了理论基础。
英文摘要	Nitrogen (N) mineralization is an important component of the soil N cycle, which is important for supplying the available N in soil to plants in addition to maintaining the plant productivity of terrestrial ecosystems.Especially, when most of grassland ecosystems were confronted with lacking of soil available N, it is more meaningful to focus on the soil N mineralization. In this study, we analyzed 3 different grasslands located along the Northeastern China Transect (NECT); specifically, a typical grassland, a transitional grassland, and a desert grassland. The soils in the 0-20 cm layer of these grasslands were incubated in the laboratory at different temperature (5, 10, 15, 20 and 25 ℃) and moisture levels (30%, 60%, and 90% saturated soil moisture (SSM) ) to evaluate differences in soil N mineralization and temperature sensitivity (Q_(10)), and to determine the main factors that regulate this process. The results showed that the total carbon, N, and phosphorus, microbial biomass carbon, and microbial biomass N of soils declined with grassland type, from typical grassland, to transitional grassland, to desert grassland. Furthermore, the total carbon, N, phosphorus, microbial biomass carbon, and microbial biomass N in soils were all significantly different among the three different grassland types (P < 0.001) .The different soil properties in different grasslands indicated that the quality of the soil substrate tended to decline from typical grassland, to transitional grassland, to desert grassland. In parallel, net soil N mineralization and soil nitrification rates decreased gradually when the soils were incubated at the same temperature and moisture levels. For example, at an incubation temperature of 20 ℃ and moisture level of 60% SSM, the soil net N mineralization rate of the three grasslands was in the following order: typical grassland (0.715 mg N kg~(-1) d~(-1)) > transitional grassland (0.507 mg N kg~(-1) d~(-1)) > desert grassland (0.134 mg N kg~(-1) d~(-1)). In contrast, the Q_(10) values increased in the following order: typical grasslandA) decreased in the following order: typical grassland > transitional grassland > desert grassland. The Q_(10) values appeared to be negatively correlated with the substrate quality index (A). Both grassland type and incubation moisture had a significant effect on the net N mineralization and nitrification rates of the soils, with significant interaction effects (P = 0.017). In contrast, these two factors (grassland type and incubation moisture) had no significant effect on soil ammonification rates. The models, using incubation temperature and moisture as variables, clearly showed the changes in the soil N mineralization rate (P < 0.0001), with R~2 ranging from 92% to 96%. This models demonstrated that within a certain threshold improving incubation temperature and moisture could promote the rate of soil N mineralization. Soil N mineralization exhibited a regular spatial pattern with the succession of grassland types from typical grassland to desert grassland, and was shown to be closely related to incubation temperature and moisture level. These data provide a new line of evidence explaining the noticeable spatial pattern of Inner Mongolian grasslands from the perspective of soil N availability.
中文关键词	草地类型 ; 温度 ; 水分 ; 土壤氮矿化速率 ; 温度敏感性(Q_(10))
英文关键词	grassland type incubation temperature moisture soil n mineralization temperature sensitivity (Q_(10))
语种	中文
国家	中国
收录类别	CSCD
WOS类目	ECOLOGY
WOS研究方向	Environmental Sciences & Ecology
CSCD记录号	CSCD:4949901
来源机构	内蒙古农业大学 ; 中国科学院地理科学与资源研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/230039
作者单位	1.中国科学院地理科学与资源研究所, 中国科学院生态系统网络观测与模拟重点实验室, 北京 100101, 中国; 2.内蒙古农业大学生态环境学院, 呼和浩特, 内蒙古 010019, 中国
推荐引用方式 GB/T 7714	朱剑兴,王秋凤,何念鹏,等. 内蒙古不同类型草地土壤氮矿化及其温度敏感性[J]. 内蒙古农业大学, 中国科学院地理科学与资源研究所,2013,33(19):6320-6327.
APA	朱剑兴,王秋凤,何念鹏,王若梦,&代景忠.(2013).内蒙古不同类型草地土壤氮矿化及其温度敏感性.生态学报,33(19),6320-6327.
MLA	朱剑兴,et al."内蒙古不同类型草地土壤氮矿化及其温度敏感性".生态学报 33.19(2013):6320-6327.