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.