马尾松纯林不同地表覆盖对产流产沙的影响研究

马尾松林地水土流失严重,为了研究马尾松林下种植植物的水土流失防治效果,选择4种不同郁闭度的林地设计3种试验小区,其中两个小区分别种植百喜草、胡枝子,与保留的自然小区进行对比试验,分析了不同郁闭度对小区产流及侵蚀产沙的影响。结果表明,当马尾松纯林地郁闭度低于0.3时,不同郁闭度间的细微差异对小区产流和产沙的影响不显著;植被盖度对小区产流和产沙的影响呈现一定规律性,当自然小区植被盖度低于30%时,产流、产沙量随植被盖度增大而下降;百喜草小区植被盖度达到45%以上时,形成乔草复层结构,比单一草被覆盖保水减蚀效果更好,且与是否有枯落物覆盖等因素有关;胡枝子小区产流、产沙量与植被盖度、乔灌草立体结构是否形成有关,人工种植胡枝子更有助于马尾松纯林形成乔灌草立体结构群落。

Study on influence of different coverage of Pinus massoniana Lamb on runoff and sediment yielding

The soil and water loss of Pinus massoniana Lamb forest is serious. To study the effect of soil and water loss control by planting under the Pinus massoniana Lamb forest, 4 forests with different canopy densities were selected to design 3 test plots, two of which were planted by Paspalum natatu and Lespedeza bicolor Turcz and one was remained as nature, to study the influ-ence of different coverage of Pinus massoniana Lamb on runoff and sediment yielding. The results show that when the canopy den-sity of Pinus massoniana Lamb is lower than 0. 3, the slight difference of canopy density has minor influence on runoff and sedi-ment yielding;the influence of plantation coverage on runoff and sediment yielding shows a certain regularity;when the plantation coverage of Pinus massoniana lamb forest is lower than 30%, the runoff and sediment yielding decrease with the increase of plan-tation coverage;when the plantation coverage in the test plot of Paspalum natatu is over 45%, the multiple community of grass and arbor was formed under Pinus massoniana Lamb forest, which is more effective than pure grass formation in water conserva-tion and sediment reduction and the effect is related with whether it is covered with litter etc. or not; the runoff and sediment yielding of Lespedeza bicolor Turcz. are related with the plantation coverage and the formation of arbor -shrub -grass cubic structure;The artificially planted Lespedeza bicolor Turcz helps form the arbor-shrub-grass cubic structure under Pinus masso-niana Lamb forest.