Abstract: Using an approach of spatial sequence instead of temporal sequence,the plant community structure,plant functional group,and forage quality were investigated on black soil bottomlands of alpine meadow along a succession gradient.The results show that a significant positive relationship was observed between species number and succession gradient:y=5.594x+0.643,(R²=0.8811);while a unimodel relationship was observed between Shannon index and succession gradient:y=-0.0528x²+0.6584x+0.3874(R²=0.7531).The relationship between biomass and succession gradient also showed unimodel pattern:y=-8.7647x²+86.696x+67.14(R²=0.6164).As for functional groups of life form,annual plants showed decreasing trend in the community,perennial grass showed increasing tendency,while sedges and perennial forbs both showed increasing tendency,in which the increasing extend for sedges slowly and for grasses sharply.Forage quality also showed different patterns along the succession gradient.With the community succession,inferior species decreased,while medium and excellent species increased greatly.However,the fine species showed different pattern as the peak biomass manifested during the 4th to 5th years of succession.These results indicated that plant community structures,plant functional group,and productive features of grassland had changed greatly along the succession gradient.

Key words: Alpine meadow, Black soil bottomland, Community succession, Species diversity, Plant functional group, Forage quality

摘要： 应用空间序列代替时间序列的方法,对高寒草甸不同恢复演替阶段黑土滩植物群落结构、植物功能群及牧草品质的变化进行了研究。结果表明:物种数与演替梯度间呈显著正相关关系:y=5.594x+0.643,(R²=0.8811);Shannon指数与演替梯度间呈非线性单峰曲线关系:y=-0.0528x²+0.6584x+0.3874(R²=0.7531);生物量与演替梯度间亦呈单峰曲线关系:y=-8.7647x²+86.696x+67.14(R²=0.6164)。一年生植物在群落中的数量呈下降趋势;禾本科植物在群落中的数量呈上升趋势;莎草类及杂类草植物在群落中的数量均呈增加趋势,但莎草类植物增幅不大,而杂类草植物则急剧增加。牧草品质随演替时间的延长而发生不同的变化:劣等牧草生物量在群落中呈下降趋势;中等和优等牧草生物量的变化趋势相同:随着演替时间的增加,均呈现幅度较大的增加趋势;而良等牧草生物量的变化则与之不同,生物量的峰值出现在演替的4-5年间。随着黑土滩的恢复演替,植物群落结构、功能群类型及草地生产性能均发生了重要变化。

关键词: 高寒草甸, 黑土滩, 群落演替, 物种多样性, 植物功能群, 牧草品质