Land use changes are of serious concern due to its effects on soil carbon stock, which is second largest anthropogenic source of atmosphere CO₂. To better understand these effects in typical and fragile ecosystems like dry-hot valley regions, we quantified changes in soil properties (pH, organic carbon, total nitrogen, phosphorus, microbial biomass carbon contents, activities of β-glucosidase, beta-N-acetyl-glucosaminidase, acid phosphatase) and CO₂ efflux before (degraded grassland) and after (mango plantation) land use change in a dry-hot valley region. Most soil chemical properties remained unaffected after conversion due to generally low regional nutrient levels. Principal component analysis revealed the decline of soil heterogeneity of the selected properties (pH, SOC, TN, TP, AP), which will be useful for future unified management. Compared to grassland, CO₂ efflux in mango plantation increased by 20–69% after land use change, more factors and their interactions were responsible for CO₂ efflux from soil in mango plantations. The temperature sensitivity (Q₁₀: 0.68–1.98) of CO₂ efflux in both land use types was low due to the low soil moisture at high temperatures. Soil water content was the primary factor affecting CO₂ efflux in the dry-hot valley region, followed by microbial biomass carbon. In summary, the CO₂ efflux increased shortly after the land use change (within first year), even though absence of significant quantitative change of soil properties, and low temperature sensitive (Q₁₀) before and after conversion and its difference between land use types is opposite in dry and wet season.

土地利用变化由于其对土壤碳储量的影响而引起了严重关注，土壤碳储量是大气CO _2的第二大人为来源。为了更好地理解典型的脆弱生态系统（如干热谷地区）中的这些影响，我们对土壤性质（pH，有机碳，总氮，磷，微生物生物量碳含量，β-葡萄糖苷酶，β- N-乙酰基活性）的变化进行了量化。-氨基葡萄糖苷酶，酸性磷酸酶）和CO ₂干热山谷地区土地退化之前（退化的草地）和之后（芒果种植）的外排。由于总体上较低的区域养分含量，大多数土壤化学性质在转化后仍然不受影响。主成分分析表明，所选特性（pH，SOC，TN，TP，AP）的土壤异质性下降，这将对将来的统一管理非常有用。与草地相比，芒果人工林的土地利用变化后CO ₂排放增加了20-69％，更多的因素及其相互作用是芒果人工林土壤中CO ₂排放的原因。CO ₂的温度敏感性（Q ₁₀：0.68–1.98）由于高温下土壤湿度低，两种土地利用类型的外排量均较低。土壤水含量是影响干热河谷地区CO ₂排放的主要因素，其次是微生物生物量碳。总之，即使在土地利用变化后不久（第一年内），CO ₂外排量也增加了，尽管在转化前后，土壤特性并没有明显的定量变化，并且对温度敏感（Q ₁₀）以及土地利用类型之间的差异没有在干燥和潮湿的季节则相反。