The Relationship Between Community Biomass And Soil Moisture,Soil Nutrient In Ziwuling Typical Forests

By research forest diversity,Soil moisture,nutrient characteristics,fine roots distribution,biomass and their mutual relations in Populus davidiana,Betula platyphylla,Pinus tabulaeformis and Quercus liaotungensis communities in Ziwuling aera of Loess Plateau,The results are as follows:1. In the succession process from Populus davidiana to Quercus liaotungensis in Ziwuling Forest,the community arbor,shrub and herbaceous layer of species decreased significantly,and the size of species among arbor,shrub and herbaceous in the four forest are: Populus davidiana,Betula platyphylla,Pinus tabulaeformis, Quercus liaotungensis; Populus davidiana's Margalef index and Shannon-Wiener index in arbor,shrub,herbaceous layer were the highest,Quercus liaotungensis'Pielou index is the highest; Quercus liaotungensis'Pielou index is the highest; Communities'Margalef index and Shannon-Wiener index is declining, In addition to artificial Pinus tabulaeformis forest,the relationship of the communities'Margalef index and Shannon-Wiener index of species is:Populus davidiana , Pinus tabulaeformis,Quercus liaotungensis; the relationship of the communities'Margalef index and Shannon-Wiener index in the four forest are: herbaceous,shrub,arbor,and the Margalef index and Shannon-Wiener index in different layer are: Populus davidiana,Betula platyphylla,Pinus tabulaeformis,Quercus liaotungensis.2. The forest vegetation communities in 2005,soil moisture was significantly higher than that in 2006,Pinus tabulaeformis soil moisture's change is small,but Quercus liaotungensis's change is larger; Populus davidiana soil moisture change is the largest in different years. Soil moisture content relationship in 0～100 cm in the four forests is: Populus davidiana,Betula platyphylla ,Quercus liaotungensis,Pinus tabulaeformis. Soil moisture content relationship in 100～300 cm in the four forests is: Populus davidiana,Betula platyphylla,Pinus tabulaeformis,Quercus liaotungensis. The relationship of bulk density in 0～60cm in different forests is: Populus davidiana,Betula platyphylla,Pinus tabulaeformis,Quercus liaotungensis. The relationship of soil total nitrogen in different forests is: Betula platyphylla,Populus davidiana,Pinus tabulaeformis,Quercus liaotungensis. The relationship of soil organic material in different forests is: Quercus liaotungensis,Populus davidiana,Pinus tabulaeformis,Betula platyphylla. The surface of the soil nutrient content is larger than the bottom.The relationship of the total root biomass is:Betula platyphylla,Populus davidiana,Quercus liaotungensis,Pinus tabulaeformis. In the succession process,the plant root length density is increase,the fine-root surface area is gradually increasing.3. In the conditions of the similar sites,human disturbance is small and the trees'age is nearly,the relationship of the single biomass is: Quercus liaotungensis, Betula platyphylla , Populus davidiana , Pinus tabulaeformis. Apart from Pinus tabulaeformis,stem biomass is the largest part in the aboveground of the organ biomass,leaf biomass is minimum. is by soil moisture content affected branches biomass significantly,the trunk is the second. Soil organic matter content affected branches biomass significantly,soil organic matter content affected strunks and leaves biomass illdefined,In addition to Betula platyphylla,The relationship of total nitrogen influenced roots biomass,litterfalls biomass and total biomass is: Betula platyphylla,Populus davidiana,Pinus tabulaeformis,Betula platyphylla.