桂东北常绿阔叶林主要群系的比较研究

桂东北常绿阔叶林分布于海拔1300m以下,类型多、分布广、面积大,在广西中亚热带森林具有重要地位。本文着重对其五个主要群系(栲树林、荷木林、云贵山茉莉林、米椎林、甜槠林)的生态地理分布、形态与结构、建群植物营养元素特征、群系发展中的稳定性进行比较研究。结果表明各主要群系在结构上相差不大,种类组成和外貌特征由于各个群系的生境不同而表现出某些差异;在建群植物灰分和主要营养元素(P,K,Ca,mg)的含量,以云贵山茉莉最高,栲树、荷木次之,米椎、甜槠最低,并与其所分布的土壤中相应元素的有效含量相一致;各建群植物对铝、锰的吸收具有选择性,荷木、米椎含高量铝、锰,栲树含高量锰,而云贵山茉莉和甜槠含铝、锰均中量;云贵山茉莉钾含量高于氮;栲树林、米椎林、甜槠林是处在较为成熟阶段的相对稳定的森林类型,而荷木林和云贵山茉莉林是在森林遭受局部破坏的情况下形成,并能迅速发展,属于不同环境的次生林。

COMPARATIVE STUDIES ON THE MAIN FORMATIONS OF THE EVERGREEN BROADLEAVED FORESTS IN NORTHEASTERN GUANGXI

The evergreen broadleaved forests under study are well preserved. They are characterized by complexity of types, abundance of tree species and distribution in a wide range of altitudes(form 300 to 1300m), they are typical humid evergreen broadleaved forests in the subtropical region of Guangxi. The specific compositions, the physiognomies, the struc-tures, the ecological distributions, the regenerations and the characteristics of the chemical elements (N, P, K, Ca, Mg, A1, Mn) have been, compared. The results show that these main formations differ little in structures. Their characteristics in specific compositions and physiog-nomies are suitable to the habitats. HuvdendTon biaristatum absorbs the most ash and chemical elments (P, K, Ca, Mg); Castanopsis fargesii and Schima superba less; and Castanupsis eyrei and Castanopsis caTlecii, the least. All these are in correspondence with the effective contents of the concerned elements in the soils, the construtive plants absorb Al and Mn selectively. The formation habitats of Castanopsis fargesii and Castanopsis carlesii are suitable for their growth and reproduction during a certain time. The formations will be able to maintain a relatively stable status. The formations of Schima superba and Huododron biaristatum belong to a secondary forest in different environments.