Heterogeneity of grassland soil respiration: Antagonistic effects of grazing and nitrogen addition
Heterogeneity of grassland soil respiration: Antagonistic effects of grazing and nitrogen addition
复制标题
草地土壤呼吸异质性：放牧与施氮的拮抗作用
DOI：
10.1016/j.agrformet.2019.01.028
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发表时间：
2019-04
影响因子：
6.2
通讯作者：
Sun Wei
中科院分区：
文献类型：
--
作者：
Shi Baoku;Xu Wanling;Zhu Yu;Wang Chengliang;Loik Michael E.;Sun Wei
放牧和氮素添加对土壤呼吸在精细空间尺度上的空间变异性的影响还知之甚少，这可能导致土壤CO2通量的估计存在很大的不确定性。我们的目标是研究放牧和氮素添加对草地结构和生态系统性质的变化如何影响SR的空间变异性，并探索其潜在的生态机制。在中国东北部的羊草草甸草原，进行了对照(CK)、放牧(G)、增氮(N)和放牧加增氮(NG)处理的操作试验。在干旱和潮湿条件下，对4个15 × 15 m样地的75个采样点同时进行了SR以及一系列地上和地下响应变量(地上生物量、根生物量、土壤水分含量、土壤养分和酶活性)的测量。与CK处理相比，G处理降低了SR的空间依赖程度。在N图中未检测到SR的空间结构。在施肥区，放牧引起的SR异质性降低幅度低于未施肥区。CK处理的SR在潮湿条件下(4.58 m)大于干旱条件下(1.61 m)。在潮湿条件下，G和NG处理的SR空间依赖程度高于干旱条件下的SR。地上和地下变量组合可以解释26-59%的SR空间变异性。驱动空间变异的因子及其对模型的贡献因处理不同而不同。结果表明，放牧和氮素添加对SR的异质性有拮抗作用。不同处理下土壤湿度的空间分布格局及其相关决定因素受土壤水分的控制。
The effects of grazing and nitrogen addition on the spatial variability of soil respiration (SR) at fine spatial scales are poorly understood, which can lead to substantial uncertainty in estimations of soil CO2flux. Our objectives were to examine how changes in grassland structure and ecosystem properties in response to grazing and nitrogen addition affect the spatial variability of SR, and to explore the underlying ecological mechanisms. We conducted a manipulative experiment with control (CK), grazing (G), nitrogen addition (N) and grazing plus nitrogen addition (NG) treatments in aLeymus chinensismeadow steppe, in northeastern China. Simultaneous measurements of SR, along with a suite of above- and below-ground response variables (aboveground biomass, root biomass, soil water content, soil nutrients and enzyme activities), were conducted for 75 sampling points in each of the four 15 × 15 m plots, both under drought and wet conditions. Compared to the CK treatment, the G treatment reduced the degree of spatial dependence of SR. No spatial structure was detected for SR in the N plot. Grazing-induced reductions in the heterogeneity of SR were lower in the fertilized plots than in the unfertilized plots. The autocorrelation range for SR in the CK treatment was higher under wet conditions (4.58 m) than under drought conditions (1.61 m). The degrees of spatial dependence of SR in the G and NG treatments under the wet condition were higher than those under the drought condition. The suite of aboveground and belowground variables explained 26–59% of the spatial variability of SR. The factors driving the spatial variability in SR and their contributions to the models varied among the different treatments. Our results demonstrated that grazing and N addition have antagonistic effects on the heterogeneity of SR. Spatial patterns of SR under different treatments and their related determinant factors are subject to control by soil water content.
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影响因子：
4.2
作者：
Shi, Baoku;Gao, Weifeng;Jin, Guangze
通讯作者：
Jin, Guangze
影响因子：
4.6
作者：
Li J;Guo C;Jian S;Deng Q;Yu CL;Dzantor KE;Hui D
通讯作者：
Hui D
影响因子：
6.9
作者：
C. Oyonarte;A. Rey;J. Raimundo;I. Miralles;P. Escribano
通讯作者：
C. Oyonarte;A. Rey;J. Raimundo;I. Miralles;P. Escribano
影响因子：
6.2
作者：
D. Sihi;E. Davidson;Min Chen;K. Savage;A. Richardson;T. Keenan;D. Hollinger
通讯作者：
D. Sihi;E. Davidson;Min Chen;K. Savage;A. Richardson;T. Keenan;D. Hollinger
影响因子：
4
作者：
Schlesinger, WH;Andrews, JA
通讯作者：
Andrews, JA