封育措施对退化与未退化矮嵩草草甸的影响

The Influence of Fencing on Degraded Kobresia Humilis Meadows and Non-degraded.

连续5年的封育处理对退化与未退化矮嵩草草甸产生了影响。研究表明,除了退化矮嵩草草甸内的均匀度指数下降不显著外,封育使两种矮嵩草草甸样地内的丰富度指数、多样性指数和均匀度指数下降都达显著水平。两种矮嵩草草甸的上下层高度均增加,其中未退化矮嵩草草甸增加显著,退化矮嵩草草甸增加不显著。两种矮嵩草草甸的枯草盖度增加显著,绿草盖度减少显著,各种群特征发生了有规律的消长。未退化矮嵩草草甸的莎草和杂类草地上生物量减少显著,枯草生物量增加显著,禾草和优良牧草的生物量以及总地上生物量增加不显著,优良牧草比例由0.57下降为0.48。退化矮嵩草草甸在封育条件下,枯草、禾草生物量增加显著,莎草、优良牧草的生物量及总生物量增加不显著,优良牧草比例则由0.29上升为0.48,达到显著水平。未退化矮嵩草草甸的草地质量指数明显下降,退化矮嵩草草甸的草地质量指数则明显上升。

5_year treatment of fencing greatly influenced degraded and non_degraded Kobresia humilis meadows.Fencing made richness index,species diversity indexes and evenness indexes decreased significantly on two plots except evenness index of degraded Kobresia humilis meadow.The heights of plant community of top layer and bottom layer were increased,especially that on non_degraded Kobresia humilis meadow.The coverage of litter was increased significantly while that of live shoots was decreased significantly on two plots under the fencing treatment.The characteristics of plant population were influenced by fencing.On the non_degraded meadow, the above_ground biomasses of sedges and forbs were decreased significantly,the litter biomass was increased significantly,the biomasses of grass and palatable herbages were not increased significantly as well as the total above_ground biomass.On the degraded meadow,the biomasses of litter and grass were increased significantly, the biomasses of sedges and palatable herbages were not increased significantly as well as the total above_ground biomass.Influenced by fencing disturbance, the proportion of palatable herbages on non_degraded meadow was decreased from 0.57 to 0.48 while that on degraded meadow was increased significantly from 0.29 to 0.48.The index of quality of non_degraded Kobresia humilis meadow was decreased significantly while that of degraded Kobresia humilis meadow was increased significantly.