Li Dandan

                                                                                                  School of Environment

Abstract: Global warming resulted from rising atmospheric concentrations of Carbon dioxide (CO2) and other greenhouse gases; it’s become the international hot issue. The effect of carbon cycling in the soil ecosystem on global climate change is intensive. Terrestrial ecosystems are a major part of soil carbon pool and play an important role in global carbon cycling. Terrestrial ecosystems can transfer between carbon source and sink. The key of solve the global climate change is to accurately estimate the net carbon source/sink function of terrestrial ecosystems. Therefore, global climate change has led to a widespread interest in the inputs and losses of carbon from soils. Among terrestrial ecosystems, urban areas play an important role in climatic changes. Soil is a major source of the production of atmospheric CO2.Given the large organic carbon reserves stored in urban soil, the release of CO2 from soil may exert positive feedback on climate changes. Small changes in the magnitude of urban soil respiration could have a large effect on the concentration of CO2 in the atmosphere. Urban green space is helpful for urban carbon cycling to derive optimal carbon fixation effects. Store carbon dynamics and carbon sink function of urban soil play an important role in urban development. In 2010-2011, we investigated spatial pattern soil respiration and soil carbon cycle in different land-use in Shenyang, Liaoning province, China. The analytical results showed that soil respiration as an important component of urban carbon cycling is influenced by many factors that vary spatially. In order to more accurately estimate the net carbon source/sink function of urban ecosystems, establish the research framework of urban carbon cycling and provide the research method of urban carbon sink. The study combination with developing policy and administrative model to propose the policy to improve the urban carbon sink function. Analyze the quantity of carbon in vegetation profiles of various land-use systems, Vegetation with multi-structure, Vegetation with simple –structure, and single vegetation pattern. The major analysis factors are the carbon input and output of vegetation and soil. With the balance calculation, total carbon input is 149.951 t, 260.617 t, 892.491 t, 5606.136 t, total carbon output is 49.23 t, 82.9 t, 355.06 t, 1745.92 t, respectively. The net carbon budget is 1169 t. Vegetation with multi-structure was the best. The results confirm the carbon sink effective of urban green space. The spatial distribution in different land-use and urban green space in Shenyang is uneven and complex. The land-use planning aims at the urban development. Meanwhile, capture the soil respiration variability characteristics and influencing factors in urban green-land. The results indicated that soil respiration has apparent seasonal and annual variation laws, its expresses in a single peak curve. Soil temperature and soil moisture are main influence factors of soil respiration. Exponential regressions model and linear equation were established to describe the relationship between soil respiration rate and soil temperature (R2 =0.9) and between soil respiration rate and soil volumetric water (R2 =0.4). The soil organic matter content one of soil fertility index has a notable relation with soil respiration rate. Vegetation with multi-structure has the lowest soil respiration.

Read the full article here:       【气候变化】沈阳城市绿地土壤呼吸特征及其碳汇分析.pdf