Response of soil respiration to precipitation during the dry season in two typical forest stands in the forest-grassland transition zone of the Loess Plateau
Response of soil respiration to precipitation during the dry season in two typical forest stands in the forest-grassland transition zone of the Loess Plateau
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DOI：
10.1016/j.agrformet.2011.02.003
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发表时间：
2011-07
影响因子：
6.2
通讯作者：
Wei-Yu Shi;R. Tateno;Jian-guo Zhang;Yilong Wang;N. Yamanaka;Sheng Du
中科院分区：
文献类型：
--
作者：
Wei-Yu Shi;R. Tateno;Jian-guo Zhang;Yilong Wang;N. Yamanaka;Sheng Du
黄土高原森林生态系统因其固碳和保持水土的特殊作用而日益受到人们的关注。在2009年5月和2010年5月的初夏干旱季节，研究了该地区森林-草原过渡带两种典型林分--刺槐种植园和辽东栎人工林土壤呼吸对降雨（27.7mm和19 mm）的响应。在这两个生态系统中，降水显着增加土壤水分，降低土壤温度，加速土壤呼吸。栎林和刺槐林土壤呼吸峰值分别为4.8和4.4μ molCO 2 m −2s− 1。在降雨后的干旱期，土壤含水量和呼吸速率逐渐下降，土壤温度逐渐升高。刺槐林土壤呼吸速率始终小于栎林，这与刺槐林和栎林土壤C、N含量和细根质量的差异是一致的。但刺槐林下单位细根质量的根呼吸（Rr）和单位土壤有机质的微生物呼吸（Rm）均高于柞树林，刺槐林下根际呼吸是引起总呼吸变化的主要成分，刺槐种植园土壤呼吸对土壤微生物呼吸和根系呼吸的贡献相当，降水量大于橡树林。
Forest ecosystems on the Loess Plateau are receiving increasing attention for their special importance in carbon fixation and conservation of soil and water in the region. Soil respiration was investigated in two typical forest stands of the forest–grassland transition zone in the region, an exotic black locust (Robinia pseudoacacia) plantation and an indigenous oak (Quercus liaotungensis) forest, in response to rain events (27.7mm in May 2009 and 19mm in May 2010) during the early summer dry season. In both ecosystems, precipitation significantly increased soil moisture, decreased soil temperature, and accelerated soil respiration. The peak values of soil respiration were 4.8 and 4.4μmolCO2m−2s−1in the oak plot and the black locust plot, respectively. In the dry period after rainfall, the soil moisture and respiration rate gradually decreased and the soil temperature increased. Soil respiration rate in black locust stand was consistently less than that in oak stand, being consistent with the differences in C, N contents and fine root mass on the forest floor and in soil between the two stands. However, root respiration (Rr) per unit fine root mass and microbial respiration (Rm) per unit the amount of soil organic matter were higher in black locust stand than in oak stand. Respiration by root rhizosphere in black locust stand was the dominant component resulting in total respiration changes, whereas respiration by roots and soil microbes contributed equally in oak stand. Soil respiration in the black locust plantation showed higher sensitivity to precipitation than that in the oak forest.