Study On Bioecological Characteristics Of Soil And Water Conservation Shurb-Vitex Negundo

The dissertation focuses on bio-ecological characteristics of Vitex chinensis Mill., one of important soil and water conservation species. The place of taking experimentation is Mi Yun county in Beijing where the capital steel diggings located. The studies primarily deal with three contents, including the germination technology of seeds in laboratory, observing growth character of plant, and investigating basic distinction of shrub population, in order to provide theoretic evidence and technical support for extension activities in soil and water conservation projects.The seeds has comparatively deep dormancy characteristic, and the epicarp is the main reason. If the seeds are dipped in gibberellin solution which is 200ppm, it will enhance the rate of germination to 69.3%, it's 1.56 times more than the rate of natural germination.For annual, from June to October is their growth cycle in a year, and for perennial, April to November is the cycle. In lean soil, the length of roots is far longer than the height of plant, but in fertile soil, the length of roots is almost equal to the height of plant. The height of annual which were sowed is 34.4cm, the length of main root is over 80cm; the height of annual which were transplanted is 40cm, and the length of main root is over 90cm.Vitex chinensis Mill. has powerful drought resisting capability, it's wilting coefficient of pot culture in productive phase is 7.4%, which is far lower than other soil and water conservation plants.The floristics of Vitex chinensis Mill shrub is fewer, and Vitex chinensis Mill is the dominant sociales, and associated species are Lespedeza davurica (Laxm.) Schindl, Zizyphus jujuba var. spinosa, Ulmus macrocarpa Hance, and Ailanthus altissima Swingle.The Vitex chinensis Mill, shrub community present vertical structure, the shrub and grass are main sunusia; the space distribution pattern is dense uniformity.