干旱半干旱区不同环境因素对土壤呼吸影响研究进展

土壤呼吸是全球陆地生态系统碳循环的重要环节,也是全球气候变化的关键生态过程。阐明和探讨影响土壤呼吸的各类环境因素,对准确评估陆地生态系统碳收支具有重要意义。干旱半干旱区是陆地生态系统的重要组成部分,研究该区域影响土壤呼吸的环境因素有助于深刻了解干旱半干旱区土壤碳循环过程。就土壤温度、土壤水分、降水、土壤有机质等非生物因子及植被类型、地上、地下生物量、土壤凋落物等生物因子两个方面对土壤呼吸的影响进行了综述。以干旱半干旱区的研究进展为主要论述对象,在上述因素中重点阐述了土壤温度、水分及其耦合作用下土壤呼吸的响应,并就土壤呼吸的Q10值及各影响因素间的交互作用进行归纳总结。在此基础上,说明了土壤温度和水分是影响干旱半干旱区土壤呼吸的主要因素。为了更准确的估算干旱半干旱区土壤呼吸速率,综合分析多种因子的交互影响,提出目前土壤呼吸研究存在的问题和今后重点关注的方向:1)不同尺度下干旱半干旱区土壤呼吸的研究;2)荒漠生态系统土壤呼吸研究;3)非生长季土壤呼吸研究;4)多因素协同作用土壤呼吸模型建立;5)测量方法的改进与完善。

Responses of soil respiration to different environment factors in semi-arid and arid areas

Soil respiration, as one of the key ecological processes, plays an important role in terrestrial ecosystems. Quantitative analysis of soil respiration is critical to assessment of ecosystem carbon budget and responses of soils to global climate change. Semi-arid and arid area covers a vast and continuous region and provides special habitats for lives,thus research in environmental factors influence on soil respiration in semi-arid and arid area is contributive to estimating soil carbon storage and understanding the process of carbon cycle. This paper summarizes the impacts of the Non-biotic factors and biotic factors including soil temperature, soil moisture, precipitation, vegetation type, aboveground and underground biomass, leaf area index, and litter on soil respiration. The interaction of the above environmental factors were analyzed with special focuses on soil temperature, moisture and the Q₁₀ value of soil respiration based on summarization of related researches. A good deal of literatures and papers indicated that soil temperature and moisture, especially in arid areas, are critical factors to soil respiration. Soil respiration is positively responded to temperature in semi-arid ecosystems or other ecosystems in dry and warm years. Compared to temperature, soil moisture plays a prominent role on soil respiration mainly due to stimulating microbial activity, and soil microbes can intensively influence the response of soil respiration. Based on the above analyses, it is suggested that the following issues should be taken into consideration for future researches: 1) spatial and temporal variation of soil respiration in arid or semiarid ecosystems; 2) process of soil respiration in arid or semiarid ecosystems; 3) soil respiration in none-growing season; 4) modeling soil respiration in relation to synergistic interaction of multiple factors; 5) improving and refining measuring methods of soil respiration.