伊犁绢蒿(Seriphidium transiliense)个体功能性状对短期禁牧的可塑性响应

为了探讨禁牧对植物个体功能性状的影响,在新疆呼图壁县、玛纳斯县及昌吉市阿什里乡对短期禁牧下蒿类荒漠草地建群种伊犁绢蒿(Seriphidium transiliense)的个体表型特征、构件生物量及其分配比进行了测定。结果表明:伊犁绢蒿个体功能性状对短期禁牧的响应因禁牧地点的差异而有所不同,呼图壁和玛纳斯样地的大多性状如株高、地上生物量、叶片数、叶生物量均呈显著增加(P 0. 05),而昌吉样地多数功能性状虽为增加,但均不显著。总体分析可知,短期禁牧后伊犁绢蒿的株高、地上生物量、叶片数、茎生物量、叶生物量依次显著增加21. 32%、48. 97%、104. 50%、50. 18%、100. 00%(P 0. 05),根颈直径、一级及三级分枝数出现显著下降,而二级分枝数、生殖生物量、各构件生物量分配比变化不显著。伊犁绢蒿个体表型性状与其构件生物量及分配比间均具有显著的联动效应,且短期禁牧可引起其部分个体功能性状间的相关关系发生显著改变。研究表明,短期禁牧促进伊犁绢蒿个体功能性状的恢复,利于退化蒿类荒漠草地的恢复。

Response of short-term grazing exclusion to individual functional traits of Seriphidium transiliense

In this study, the phenotypic traits, biomass and allocation ratio of Seriphidium transiliense in the sagebrush deserts in Manas County, Hutubi County and Ashili Township of Changji City in Xinjiang were measured so as to understand the response mechanism of grazing exclusion. The response of individual functional traits of S. transiliense to short-term grazing exclusion was different from the different experiment plots, most of the traits, such as the plant height, aboveground biomass, leaf number and leaf biomass in Hutubi and Manas plots, were increased significantly (P<0.05), yet most of the functional traits in Changji plot were increased but not significantly. Compared with the control, the plant height, aboveground biomass, leaf number, stem biomass and leaf biomass of S. transiliense were significantly increased by 21.32%, 48.97%, 104.50%, 50.18% and 100.00% respectively (P<0.05), while the taproot diameter, first-grade branch number and third-grade branch number were decreased significantly, but there were no significant changes in the second-grade branch number, reproductive biomass and biomass allocation ratio (P<0.05). There was a significant linkage effect between the phenotypic traits and biomass allocation of S. transiliense, and the short-term grazing exclusion could significantly change the correlation of individual functional traits. In short, the short-term grazing exclusion could promote the recovery of individual functional traits of S. transiliense and facilitate the regeneration of degenerated sagebrush desert grassland.