高原鼠兔干扰对达乌里秦艽繁殖特征的影响

Effects of disturbance of plateau pika(Ochotona curzoniae) on reproductive characteristics of Gentiana dahuricain the Qinghai-Tibetan Plateau

高原鼠兔(Ochotona curzoniae)通过掘土和采食等行为对高寒草甸产生广泛的影响,从而影响高寒草甸植物的繁殖特征。本研究以高山嵩草(Kobresia pygmaea)草甸达乌里秦艽(Gentiana dahurica)为对象,采用野外调查法研究了高原鼠兔干扰对其繁殖特征的影响。结果表明,随着高原鼠兔干扰水平的增大,达乌里秦艽的地上生物量、株高、茎叶比、生殖枝数、营养枝数、花序数、花序生物量和单株种子产量均呈增加态势。干扰水平为Ⅰ(112±32)个·hm-2和Ⅱ(192±48)个·hm-2时,达乌里秦艽所同化的物质主要分配于同化器官叶中,以保证种群的生存;当干扰水平增大到Ⅲ(352±64)个·hm-2和Ⅳ(608±48)个·hm-2时,达乌里秦艽将其所同化的物质更多地分配于生殖生长,形成更多的生殖枝数、花序数和单株种子产量,从而提高了达乌里秦艽的繁殖能力,一定程度上解析了高原鼠兔过度干扰劣化高山嵩草草甸放牧品质的途径。

Activities of plateau pika(Ochotona curzoniae)affects reproductive characteristics of different plant in alpine meadow communities by excavating and feeding.A field survey was conducted to determine the effects of disturbance of plateau pika on reproductive characteristic of Gentiana dahurica.The present study showed that aboveground biomass,plant height,stem-leaf ratio,number of reproductive shoot,number of vegetative shoot,number of inflorescence,inflorescence biomass and seed yield per plant all increased with the increase of disturbance levels of plateau pika.When the disturbance levels wereⅠ(112±32)hole·ha-1 andⅡ(192±48)hole·ha-1,more assimilate substances in G.dahuricahave allocated in the leaves to guarantee the survive of the populations.When the disturbance levels were Ⅲ(352±64)hole·ha-1 and Ⅳ(608±48)hole·ha-1,more assimilate substances in G.dahurica have allocated in the reproductive organ to form more reproductive shoots,inflorescences and seed yield per plant.In conclusion,the excessive disturbance of plateau pika decreased grazing quality in alpine meadow by improving reproductive growth of G.dahurica.