不同退化程度"黑土滩"高山嵩草克隆生长特性

Growth characteristics of Kobresia pygmaea clones in the "black soil beach" with different degradation

对不同退化程度"黑土滩"高山嵩草无性系分株构件和克隆生长进行了研究,结果表明,在一定退化程度下随着无性系面积的增大,高山嵩草营养分株、生殖分株数量及生物量均趋于增大,极度退化的草地中无性系变化无此规律。在轻度、中度和重度退化程度下,随着退化程度的增加,高山嵩草无性系营养分株能力加强,生殖分株能力减弱;极度退化的草地已呈现典型的"黑土滩"景观,高山嵩草的克隆生长维持在最低水平。高山嵩草分蘖节直径伴随着退化程度的加大有增加的趋势,分蘖节距离地面的高度变化不明显。

In order to understand the effect of grazing on the growth of Kobresia pygmaea clones in the 'black soil beach' with different degradation, experiments about ramet and biomass of these clones were conducted. The results revealed that under certain degree of degradation, with the increase of clone area, the amount of ramets and biomass of the clones increased, while the mean number of tillers and leaf blades and biomass were not tended to increase. This phenomena was not observed in those clones which grew in grassland with extreme degradation. Under light, middle and heavy degradation, with the increase of degradation, the vegetative ramet capacity of the clones increased, while their reproductive ramet capacity decreased. A typical landscape of 'black soil beach' appeared in grassland with extreme degradation; the growth of the clones was in a lowest level. With the increase of degradation, the diameter of tiller node increased, while the changes of its height apart from above ground were not obvious.