农牧交错区弃耕地生境中白草无性系的形态可塑性研究

通过对内蒙古科尔沁沙地农田弃耕地上白草的观测与取样分析,发现生长在不同微生境下的白草无性系表现出显著的形态可塑性和不同的生物量分配模式,主要表现在:①沿着白草总生物量减少的梯度,其根冠比呈增加的趋势,后者与土壤容重有显著的相关性;②白草地下生物量的分布与土壤水分状况相关联,根茎长度的分布格局与地下生物量分布格局存在高度的一致性;③单位长度根茎上的节数(或平均节间长度)以及不定芽数分别与土壤有机质含量和水分含量存在显著相关性。

Morphological Plasticity of Pennisetum centrasiaticum Clones in Abandoned Farmland in Ecotone of Farming and Animal Husbandry

Growth,morphology and biomass distribution of Pennisetum centrasiaticum clones in different microhabitats of abandoned farmland in Horqin Sandy Land of Inner Mongolia were compared.The clones had significant morphological plasticity and different biomass distribution pattern in different microhabitats:1) as the total biomass of P.centrasiaticum decreased along the gradient,its root/shoot ratio increased,and ratio was closely related to soil volume weight;2) the distribution of underground biomass was associated with water content of the soil,and rhizome length distribution followed the same pattern;and 3) number of nodes per unit length of rhizome(or mean internode length) was significantly correlated with soil organic matter content,and number of adventitious buds per unit length of rhizome was significantly correlated with soil water content.