草地雀麦坡地水土保持作用的研究

为研究草地雀麦的水土保持作用，在延庆县选择25。坡地建立了相应的径流试验小区，并对土壤侵蚀量、土壤水分、土壤紧实度以及根系地下生物量等指标进行了测定。结果表明，种植草地雀麦能显著减小荒坡地水土流失。土壤侵蚀量随植被覆盖度增加而逐渐减小，当植被覆盖度为90％时，年径流量和侵蚀模数仅为14233．19m^3／km^2和57．82t／（km^2·a），保水固土能力分别可达67．8％和98．31％。种植草地雀麦后，浅层（0～30cm）土壤的紧实度显著增加，10cm土层深度处是对照地的1．72倍，雨后土壤水分动态变化趋势平缓，保水效果显著；草地雀麦根系的98．1％集中分布于0—30cm土层。

Species Diversity in the Wind-sandy Grass Shoal Area of Yulin Region

In order to study the roles of meadow brome in soil and water conservation, 6 runoff plots were established on a 25 sloping land in Yanqing County.Soil loss, soil water content, soil compaction, and the root system were measured.Results showed that the effects of meadow brome planted on the slope were evident in preventing soil loss.Soil and water loss descended with the coverage increasing.When the coverage was 90% , the yearly amount of surface runoff and soil erosion modulus were 14 233.19 m³/ km²and 57.82 t/( km²! a) , respectively, and the capabilities of water conservation and soil conservation were 67.8% and 98.31%, respectively.Meadow brome planting effectively increased the compaction within 30 cm of surfacesoil.Especially at 10 cm soil depth, the compaction was 1.72 times of CK.The water dynamic change of the soil covered by meadow brome was gentle in comparison with that of CK.Meadow brome maintained the water content in the soil obviously.The root system was mainly distributed in the soil layer of 30 cm, accounting for 98.1%.