The Influence of Fencing on Degraded Kobresia Humilis Meadows and Non_degraded

27 Mar The Influence of Fencing on Degraded Kobresia Humilis Meadows and Non_degraded

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Abstract

: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

English Abstract

: 5_year treatment of fencing greatly influenced degraded and non_deg raded
Kobresia humilis meadow s . Fencing m ade richness index , species diversity indexes and
evenness indexes decreased significantly on two plots except evenness index of deg raded
Kobresia hum ilis meadow . The heights of plant community of top layer and bo ttom layer were increased , especially that on non_deg raded Kobresia humilis meadow . The coverage of litter w as increased significantly w hile that of live shoots w as decreased significantly on two plo ts under the fencing treatment . The characteristics of plant population w ere influenced by fencing . On the non_degraded meadow , the above_ground biomasses
of sedges and forbs w ere decreased significantly ,the litter biomass w as increased significantly ,the biomasses of grass and palatable herbages were not increased significantly as
w ell as the total above_ground biomass. On the degraded meadow , the biomasses of litter
and grass w ere increased significantly , the biomasses of sedges and palatable herbages
w ere 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 w hile that on degraded meadow w as increased significantly
from 0 . 29 to 0 . 48 . The index of quality of non_degraded Kobresia hum ilis meadow was
decreased significantly w hile that of degraded Kobresia hum ilis meadow w as increased
significantly