几种高山牧草间的联结性在融雪梯度上的变化

Variation of Interspecies Association among Several Herbage Populations along Snowmelt Gradient

以青藏高原东部的一个天然高山雪床为样点,根据融雪梯度,设置早融、中间和晚融3个融雪部位,并对各个部位几种优势牧草种群间的联结性进行比较。结果表明:几种优势牧草的总体关联性在早融部位表现为正联结,中间部位表现为无联结,而晚融部位则表现为负联结。各种对间的联结性以早融部位正联结占多数,中间部位正负几乎各占50%,晚融部位负联结占多数。在早融部位以黑褐穗苔草和圆穗蓼间的联结性强度最强,中间部位以黑褐穗苔草和川西小黄菊间的联结性最强,晚融部位以川西小黄菊和圆穗蓼的联结性最强。说明,融雪时间对高山草地物种间联结性的影响较大。

The interspecies association among several dominant populations in 3 portions（early,mid,and late-melting portion）,which were established along snowmelt gradient was compared in a natural alpine snow bed on eastern Qinghai-Tibetan plateau.The results showed that the overall association among the dominant species appeared positive association,no association,and negative association in early-melting,mid-melting,and late-melting portions,respectively.In terms of association correlation coefficients in each species pair,positive association was in majority in early-melting portion,almost half positive and half negative in mid-melting portion,and negative was in majority in late-melting portion.Carex atrofusca subsp.minor and Polygonum macrophyllum had the strongest association in early-melting portion,while in mid-melting portion was association of C.atrofusca subsp.minor and Pyrethrum tatsienense,and in late-melting portion was association of P.tatsienense and C.atrofusca subsp.minor.It indicated that snowmelt time had a strong effect on interspecies association in alpine meadow community.