The use of soil respiration as an ecological indicator in arid ecosystems of the SE of Spain: Spatial variability and controlling factors
The use of soil respiration as an ecological indicator in arid ecosystems of the SE of Spain: Spatial variability and controlling factors
复制标题
DOI：
10.1016/j.ecolind.2011.08.013
复制
发表时间：
2012-03
影响因子：
6.9
通讯作者：
C. Oyonarte;A. Rey;J. Raimundo;I. Miralles;P. Escribano
中科院分区：
文献类型：
--
作者：
C. Oyonarte;A. Rey;J. Raimundo;I. Miralles;P. Escribano
在对Cabo de Gata-Níjar自然公园（西班牙东南部）进行监测研究的背景下，我们探索了利用土壤呼吸作为反映半干旱环境中生态过程变化的生态系统功能指标。为此，我们在一年中的两个不同时期(夏季（旱季）和春季（生长期）测量了自然公园六个不同且具有代表性的生态系统的土壤二氧化碳通量，这些生态系统具有不同的土地利用（森林和农业用地）和不同的土壤覆盖（植物和裸露土壤）。我们还测量了主要土壤性质和环境变量。干旱期土壤co2通量为0.40μmolm−2s−1，生长期为1.93μmolm−2s−1。土壤co2外排表现出较大的空间变异性，在不同的测量时段表现出不同的特征。枯水期生态系统间的差异（CVs 75 ~ 80%）大于生态系统内的差异（CVs 40 ~ 55%），生长期生态系统间的差异（CVs 40 ~ 50%）较小，生态系统间和生态系统内无差异。控制土壤co2外排的因素在两个测量场合也存在差异。干旱期土壤co2外排主要是土壤运输过程的结果，因此与生态系统条件下的局部因子（OC含量、CN比、粘土、岩石露头等）有关；生长期土壤co2外排主要受土壤co2产量的影响，因此只与有机碳含量和植物覆盖有关。在生长季节，环境变量解释了大约10%的土壤co2外排变化。为了在一年的不同时间捕捉这些不同的过程，即扩散与生产过程，我们计算了一个新的指数，土壤呼吸的正常化季节差异（SDSR），这被认为是生态系统状态和功能的一个很好的指标。
In the context of an ongoing monitoring study of the Cabo de Gata-Níjar Natural Park (SE of Spain), we explored the use of soil respiration as an indicator of ecosystem functioning reflecting changes in ecological processes in semiarid environments. With this purpose, we measured soil CO2efflux in six different and representative ecosystems of the Natural Park, with different land uses (forest and agricultural sites) and under different soil covers (under plant and bare soil) in two distinctive periods of the year: summer (dry period) and spring (growing season). We also measured the main soil properties and environmental variables. Soil CO2efflux ranged from 0.40μmolm−2s−1in the dry period to 1.93μmolm−2s−1in the growing season. Soil CO2efflux showed a large spatial variability, with different behaviour between the measured periods. Whereas in the dry period differences among ecosystems were larger (CVs 75–80%) than within them (CVs 40–55%), in the growing season the CVs were smaller (40–50%) and no differences were observed between or within ecosystem. The factors controlling soil CO2efflux also differed in the two measurement occasions. Whereas in the dry period soil CO2efflux was mainly the result of transport processes in the soil and therefore related to local factors (OC content, CN ratio, clay, rock outcrop, etc.) assigned to ecosystem conditions, in the growing season soil CO2efflux was dominated by soil CO2production and thus related only to organic carbon content and plant cover. In the growing season environmental variables explained ca. 10% of the variation in soil CO2efflux. In order to capture these different processes in different times of the year, i.e., diffusion versus production processes we calculated a new index, normalised seasonal difference in soil respiration (SDSR), which is proposed as a good indicator of the state and functioning of the ecosystem.