毛乌素沙地克隆植物对风蚀坑的修复

通过在根茎型克隆植物沙鞭和赖草的种群中设置模拟风蚀坑,研究了根茎禾草沙鞭和赖草对风蚀坑的修复能力及其机理。实验结果表明:沙鞭和赖草都能通过克隆拓展在风蚀坑中产生比自然条件下更多的分株,以更好利用风蚀坑中充足的光照,从而具有很强的风蚀坑修复能力;但同时这些分株的生长也受到风蚀坑中养分条件的制约,生物量、叶片数量和分株高度都不如自然条件下形成的分株;赖草通过间隔子的可塑性反应,将更多的新生分株放置在风蚀坑内,从而具有更强的修复能力。赖草对风蚀坑的修复主要是通过周围根茎扩展进入坑中,然后产生新的分株;而沙鞭不仅可以通过周边根茎进入产生新的分株,同时也可以通过更深层次的根茎来产生新的分株。

Remediation of blowout pits by clonal plants in Mu Us Sandland

In order to study the ability and mechanism of sandland blowouts remediation by two clone plants L. secalinus and P. villosa, man-made blowouts were set up in the populations of two clonal plants. The results showed that, both clonal plant species had produced more new ramets in the blowouts than in the natural quadrats, suggesting that clonal plants had strong ability in blowouts remediation; while the biomass, number of leaves and ramet height of these ramets were smaller in blowouts than in natural quadrats, due to the poor nutrient. L. secalinus had stronger ability of vegetation remediation than P. villosa, for it had produced more new ramets in blowouts through the plasticity of spacers. The new ramets of L. secalinus in blowouts were produced by the buds in the rhizomes which spread from outside of blowouts; whereas which of P. villosa were produced both by the buds in the rhizomes which spread from outside, and by the buds in the rhizomes inside which were freed from dormancy under wind erosion condition.