丹霞地貌山顶生态效应

首次探讨了丹霞地貌山顶生态效应现象,揭示特殊的地貌、形态所产生的特殊生态现象.测定广东省丹霞山宝珠峰和海螺峰的山顶的生态因子特征、群落结构特征和物种生态型特征,并与山脚的群落与种群以及相近非丹霞地貌区作比较.结果表明,山顶的平均温度高于山脚沟谷,平均湿度小于山脚沟谷,群落物种数和物种多样性均小于山脚沟谷.相比山顶而言,山脚沟谷的植物有很强的热带性.这些特征都有别于一般非丹霞地貌山地.另外,在山顶和山脚调查的几个种群在叶面积、比叶面积、树皮、枝下高和冠幅等方面,均出现了生态型的差异.讨论了丹霞地貌山顶对生态型研究、岛屿理论研究和适应性进化研究的科学意义.

The ecological effect on the hilltop of Danxia Landform

The hilltop ecological effect of Danxia Landform generated by the distinct physiognomy and topography was investigated. The characteristic differences in ecological factors, community structure and species ecotype between hilltop and foot gulch were determined, which were compared with those of non- Danxia Landform. The results showed that the mean daily temperature on the hilltop was higher than that at the foot gulch, but the average relative humidity and community diversity on the hilltop were lower than those at the foot gulch. In contrast to those on the hilltop, plants at the foot gulch showed stronger tropical character. All of characteristics above were different from those in other Landforms. In addition, ecotypic differentiations in leaf area, specific leaf area, bark, height under branch and crown width were found between hilltop and foot gulch in the studied species. Moreover, the hilltop of Danxia Landform was though to be of significance in the scientific researches of ecotype, island biogeography and adaptive evolution. Further studies are needed in order to better understand the universality of ecological effect on the hilltop of Danxia Landform.