Effects Of Management Measures On Above-and Below-ground Biomass Of Plant Community On Alpine Meadow

By using field investigation, the effects of management measures, including fencing, reseeding, fertilizing and comprehensive, on species richness, above-and below-ground productivity, and their relationships were studies on alpine meadow in Gansu province, Maqu county, Aazi pasture. The results indicated that:1. Compared with controls, species richness of different treatments decreased significantly, the orders were control (33species)> fencing (27species)> fertilizing (21species)> reseeding (17species)> comprehensive (14species). Functional group composition, however, did not changed in all treatments, consisted of grasses, sedges, legumes and forbs. The species richness within each functional group had different patterns. Grasses and legumes had no significantly changes(P>0.05), sedges decreased significantly within reseeding and comprehensive (P<0.05). The species richness within forbs, however, decreased greatly (P<0.01)2. Different treatment measures had important influence on above-ground productivity. Compared with controls, the productivity of all treatments increased significantly (P<0.01), among which, comprehensive increased191.88%, reseeding, fertilizing and fencing increased129.48%、99.57%and80.76%respectively. Within functional groups, the productivity of grasses, sedges and legumes exceeded controls notably (P<0.01), while productivity of forbs reduced obviously (P<0.01)3. Different treatment had positive effects on below-ground productivity in0-30cm soil layers. The increase ranges was fertilizing82.25%, comprehensive69.96%, reseeding25.84%and fencing17.45%, respectively. Below-ground productivity decreased from0cm to30cm, presented as T shape. The increasing range maximized during0～10cm, being fertilizing130.34%, comprehensive101.23%, reseeding43.99%and fencing30.41%, respectively.4. In total, aboveground productivity increased with belowground productivity, and showed significant positive relationships. The relationship between above-and below-ground productivity of different functional groups, however, showed different patterns:grasses had significant positive relationship, sedges and legumes had no significant correlations, while forbs showed a negative correlation.5. Different management measures had negative effect on root/shoot ratio. Compared with controls, the value of root/shoot ratio decreased significantly, the order was control2.47, fertilizing2.25, fencing1.72, comprehensive1.44and reseeding1.30.