江西九连山常绿阔叶林下土壤的物理性质、水分状况及水源涵养能力的初步研究

我们在江西省九连山自然保护区对山地常绿阔叶林下的土壤进行了土壤物理性质和土壤水分季节动态的测定(一年连续),并据此对其水源涵养能力进行了初步分析。这种土壤具有良好的物理性质,质地主要为壤质粘土和粘壤土,容重小(0.88—1.29),孔隙度大(51.7—65.4％),透水速度快(17.4—142.8ml/min),最大持水量高(占容积50.6—58.2％)。土壤排水良好,水分充足。水分含量一年中绝大部分时间在30％以上。变动范围:0—15cm土层,26—56％;15—30cm土层,26—45％;30—50cm土层,26—45％。我们用透水速度和最大持水量来分析其水源涵养能力,并与丘陵红壤进行比较。结果是:土壤的透水能力为丘陵红壤的3—5倍;贮水能力为丘陵红壤的138—145％;吸收雨水能力为丘陵红壤的219％。

A PRELIMINARY STUDY ON THE PHYSICAL PROPERTIES, MOISTURE CONDITION, AND WATER RETENTION ABILITY OF THE SOIL UNDER THE EVERGREEN BROAD-LEAVED FOREST OF THE JIULIAN MOUNTAIN-IN JIANGXI PROVINCE

The soil that we studied is located on the Jiulian mountain natural reserve of Jiangxt province, and is under the evergreen broad-leaved forest. It is a moumainouns soil. We deter-mined the physical properties and the seasonal dynamic change of soil moisture (for one year in succession) of the soil, and with these data we analysed the water retention ability of the soil.The soil possesses good physical properties: the soil texture is mainly loamy clay and clay loam, the bulk density is small (0.88-1-29), the porosity is large (51.7-65.4%), the permeable velocity is fast (17.4-142.8cc/min), and the maximum moisture holding capacity is high (occupying 50.6-58.2% Of the volume).The drainage of the soil is good, and the moisture of the soil is sufficient. The moisture content is more than 30% in most part of the year. The annual ranges of moisture content are: 0-15cm layer, 26-56%; 15-30cm layer, 26-45%; and 30-50cm layer, 26-45%.We analysed the water retention ability of the soil with the dafa of prermeable velocity and maximum moisture holding capacity of the soil, and compared it with the red soil of the hilly land, the results are as follows: the permeability is 3-5 times as much of the red soil; the capability of absorbing rainfall is 219% of the red soil.