栓皮栎种群的性状分化与地理变异性研究

同一种群个体在不同的环境条件下会表现出一定的性状分化．这种由于地理差异引起的种群间性状的变件，反映了种群应对不同生境条什的进化方式和适应对策。研究表明：不同生境的栓皮栎种群性状参数分化差异明显。栓皮栎种群的叶柄长、叶长、叶宽、栓皮厚度、种长和种宽随纬度呈现出二次抛物线关系；叶柄长、叶长和栓皮厚度随海拔高度晕现明显的二次抛物线关系；叶宽和种宽随海拔高度的变化呈现出明显的正线性相关；种长与海拔的关系为一种典型的负线性相关。可见，由于纬度和海拔梯度的连续变化，使与之相关的生境因子也呈现出一个渐变的过程，塑造出在性状特征上有差异的种群。因而，当种群性状参数随地理纬度和海拔的变异模式确定后，就可以大体揭示种群性状分化的规律和变化趋势。

Trait Differentiation and Geographical Variability of Quercus variabilis Community

The individuals of same communities display trait differentiation under different environmental conditions to certain extent ,and the trait differences of the communities that result from geographical differences of the communities reflect the evolution ways and adapting strategies of the communities under different habitat conditions. The study showed that the Quercus variabilis communities in different habitats significantly differentiated in their trait parameters. The petiole and leaf lengths and leaf widths and cork thicknesses and seed widths of the Quercus variabilis communities appeared to have a second-degree parabola relation with the latitudes of the communities;the petiole lengths and leaf lengths and cork thickness appeared to have a clear second-degree parabola relation with the elevations of the communities;the leaf and seed lengths appeared to have a clear positive correlativity with the elevations ;the seed lengths had a typical negative correlation with the elevations. These showed that the progressive changes of the latitudes and elevations made the habitat factors present a progressive changes thereby leading to the trait-differentiated communities. Therefore, the trait differentiation and variations of the communities would be known where the model to describe how the trait parameters of the communities varied with the latitudes and elevations of the communities.