[Objective] In order to provide the theoretical basis for evaluating the effect on soil microbial properties and for establishing reasonable sustainable forest management to reduce soil erosion and land degradation, soil chemical properties and microbial biomass of main tree species-Robinia pseudoacacia and Quercus varaibilis in rocky mountain area of northern China were studied. [Methods] The chemical properties, microorganism amount, microbial biomass carbon and nitrogen in soil of R. pseudoacacia and Q. varaibilis plantations were analyzed. The factors influencing soil fertility were also studied with principal component analysis and stepwise regression analysis. [Results] The results showed that three kinds of main soil microorganisms and microbial biomass carbon and nitrogen decreased with the deepening of the soil depth. The amount of soil bacteria in the R. pseudoacacia plantation was 2.13-2.26 times that in the soil of Q. varaibilis plantation. While the amount of actinomycetes in the soil of Q. variabilis plantation was 4.48-6.05 times that in the soil of R. pseudoacacia plantation. No obvious difference was observed between the amounts of fungi in these two kinds of forest soil. The content of nitrate nitrogen, organic matter, available phosphorus and the total amount of microbes, microbial biomass carbon and nitrogen in the soil humus layer of R. pseudoacacia plantation were significantly higher than that of Q. variabilis plantation. [Conclusion] (1) The soil physical and chemical properties and the number of microorganisms and microbial biomass carbon/nitrogen could be used to reflect the variability of soil fertility in this area. (2) The main factors affecting the total amount of microbes and microbial biomass carbon/nitrogen are total nitrogen, available phosphorus and available potassium. (3) Planting R. pseudoacacia is more conducive to the ecological restoration of soils than planting Q. varaibilis.

目的 研究荆条灌丛的潜在蒸散量及作物系数变化趋势，为半干旱区水资源管理及植被建设提供依据。 方法 利用河南黄河小浪底地球关键带国家野外观测站2021年5—10月份的蒸渗仪数据、逐日气象数据、荆条叶面积指数（LAI）及新梢生长量数据，利用Penman-Monteith公式计算参考作物蒸散量（ET₀），分析生长状况基本一致、水分充足条件下的荆条不同生育期的潜在蒸散量、作物系数的变化趋势及其与生长指标的关系。 结果 （1）在荆条生育期内，ET₀值整体呈下降趋势，5、6月份较高，7月份后开始下降，ET₀总值为630.86 mm，日均值为3.43 mm·d⁻¹。（2）荆条生育期内荆条灌丛的潜在蒸散量呈抛物线式变化，表现为开花期最大，总值为336.26 ± 18.19 mm，日均值为5.51 ± 0.30 mm·d⁻¹；结果期和展叶期次之，落叶期最小，总值为41.57 ± 3.61 mm，日均值为1.98 ± 0.17 mm·d⁻¹；整个生育期的总值为716.47 ± 40.21 mm，日均值为3.89 ± 0.22 mm·d⁻¹。（3）荆条灌丛LAI和新梢生长量在5、6月增长较快，之后变缓。其中LAI在8月达到最大值（2.93 ± 0.07），之后开始下降，10月降为最小值（1.63 ± 0.08）。新梢在5月增长量最大，为6.85 ± 0.25 cm，10月基本停止生长。（4）荆条作物系数在生育期内呈先增后降的变化趋势，结果期最大（1.45 ± 0.22），开花期次之（1.25 ± 0.13），展叶期（0.98 ± 0.05）和落叶期（0.95 ± 0.14）最小，整个生育期平均为1.28 ± 0.16。作物系数与叶面积指数呈极显著正相关（p＜0.01），决定系数R²为0.736，与新梢生长量相关性不显著（p＞0.05）。