水保所知识产出(1956---)知识库

表明:(1)侵蚀导致坡面土壤 CO 2 通量的空间分异格局,具体表现为沉积区(S)>对照区(CK)>侵蚀区(E);有机碳水平的提高可以整体促进各部位
CO 2 通量的增加.(2)侵蚀可导致土壤水分、容重和团聚体稳定性降低,引起土壤养分流失,降低细菌、真菌多样性;沉积则引起相反的现象.侵蚀/沉积过程
对土壤温度的影响并不显著.有机碳水平的增加可以有效改善土壤颗粒、土壤水分,增加容重,抑制土壤养分的流失、增加细菌,降低真菌多样性.(3)结构
方程模型解析了侵蚀部位、土壤温度、土壤水分、有机碳(SOC)、水溶性碳(DOC)、微生物碳(SMBC)、真菌多样性、细菌多样性对于 CO 2 通量的多
因素耦合驱动机制(R 2 =77%),明确了土壤温度、土壤水分、微生物碳为 CO 2 通量的直接影响因子.在水热双因子模型的基础上, 嵌入能够间接表征微生
物活性和有效碳底物的 C 因子,分段(按照坡面侵蚀部位)建立 T&M&C 模型,可以较为准确地测算侵蚀坡面不同部位 CO 2 通量(R 2 >67%).

On eroded slopes with different soil organic carbon (SOC) levels in loess hilly region, the spatial differentiation patterns
driving factors and process mechanisms of CO 2 fluxes were analyzed, and a subsection model of CO 2 fluxes was constructed. The
results showed that: (1) The spatial differentiation patterns of soil CO 2 flux on slopes caused by erosion was as follows: sedimentary
area (S) > control area (CK) > eroded area (E); the increase of SOC level can promote the increase of CO 2 flux in all parts of slope.
(2) The erosion reduced soil moisture, bulk density and aggregate stability, cause soil nutrient loss, reduce bacteria diversity and
fungal diversity; sedimentation caused the opposite phenomenon. The effect of erosion/sedimentation process on soil temperature
was not significant. The increase of SOC level can effectively improve soil particles, soil moisture, increase bulk density, inhibit soil
nutrient loss, increase bacteria diversity but reduce fungal diversity. (3) Our structural equation model analyzed the multi-factor
driving mechanism of erosion location, soil temperature, soil moisture, SOC, DOC, SMBC, fungal diversity and bacterial diversity
on CO 2 flux (R 2 =77%). Our model also identified soil temperature, soil moisture and SMBC as the direct influencing factors of CO 2
flux. Based on the two-factors hydrothermal model, the T&M&C model was built by embedding the C factor which could indirectly
represent the microbial activity and available carbon substrate, thus allowing to estimate more accurately the CO 2 flux in different
parts of the erosion slope (R 2 >67%).