| In recent years, the global environment change have close relations between biological diversity and ecosystem function, the biodiversity sharply reduce impact on biological community productivity. Qinghai-tibet plateau climate special, the grassland ecological environment fragile, in order to maintain stable development of grassland ecological environment function, It is important and significance to research the influence of the relationship between the loss of species diversity of community productivity. This experimental research is the use of artificial simulation of loss of diversity of different plant functional group, In the Chinese academy of sciences of the haibei kobresia humilis meadow ecosystem research station, short song grass meadow observation of sample area to carry out the experimental study. By removing different plant functional groups, the ground biomass(fresh weight and dry weight), species and after loss of plant diversity, plant height and coverage as the measure of the plant community structure to compare different plant functional group on the influence of soil nutrient and soil moisture loss, in order to illustrate the loss of plant diversity of species diversity and productivity of the relationship between response, for biodiversity protection and grassland ecological restoration.To provide some scientific basis.The following main conclusions:(1) different plant functional group to eliminate make species diversity loss, biomass on the ground in RG and RCFL,showing significant differences(p < 0.05); It is different of underground biomass at different soil depth, 0 ~ 10 cm layer, RF、 RCFL and RAP showed significant difference(p < 0.05), 10 ~ 20 cm layer, each treatment and there was no significant difference, 20 ~ 30 cm layer, only RAP and controlled comparison show significant difference. The influence degree of the fresh weight RG > NM > RL > RF > SG > RCFL, the influence degree of the dry weight NM > RF > RL > RG > SG > RCFL.(2) in June, 0 ~ 5 cm and 5 ~ 10 cm soil humidity, most of the processing and comparing, characterized by significant differences, in July, 5 ~ 10 cm and 10 ~ 15 cm of simulated grazing were significant(p < 0.05), explain the eating of the livestock and tread soil compactness increased, soil moisture increased; Completely eliminate all plant processing and comparison of photography, soil moisture of each layer were significantly difference(p < 0.05). Different plant functional absorption performance of different degree of soil nutrients, organic matter content in RAP was reduced by 10%, removed due to its plants, plant diversity loss, soil aggregate institutions is less, the soil becomes barren, the roots of the plant litter decomposition rate is low, also reduce the decomposition of soil organic matter content, stability of aggregate.(3) to simulate the loss of plant diversity, it can change the plant community structure, height measurement based on different plant functional group, RF and RCFL height has increased significantly, RF height of the gramineous plants show very significant difference, RF coverage reached the highest.(4) the influence of the species and community primary productivity, RF、 RAP and compare with NM,species showed significant difference(p < 0.05), the extent of the influence of the species RCFL > RF > RG > NM > SG > RL, an average performance the influence degree of the aboveground biomass of RCFL > SG > RG > RL > RF, species does not affect productivity. RF and RL of species were 11.4 and 23.6 on average, in dealing with the mean value of the primary productivity and natural conditions of primary productivity. |
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