粤北通天箩石灰岩阱洞的植物及其与生态条件的关系

 通天箩在广东北部乳源县的岩溶地区，是一个陷入地中达95m深的大型垂直阱洞，阱口直径73m，阱底最大直径140m，阱壁陡峭，各种证据表明，自古以来没有人下过阱。我们经过3次探险下阱调查，发现阱底中部生长着面积约3500m2的常绿阔叶林，还有不少藤本植物和蕨类植物，共有蕨类植物6科、8属、12种，被子植物46科、61属、80种(包含变种)；这些植物区系是在光照不足和石灰岩基质发育的土壤上存在和发展起来，从未受过人类的干扰。

PLANTS IN TONGTIANLUO CAVE OF GUANGDONG PROVINCEAND THEIR RELATIONS WITH ECOLOGICAL CONDITIONS

Tongtianluo cave is located in the Karst region of Ruyuan county, in the north part of Guangdong province(24°59′N;l13°7′E). It is a huge vertical cave formed by the subsidence of the earth′s surface, with precipitous wall. The diameter of the cave is 73m at its mouth, and 140m at its bottom (along the widest direction). There is no record of exploration to the cave before ours. The evergreen broad-leaved forests were discovered on a areas of 3500m2 at the bottom of the cave, with lots of vines and Pteridophytes. The 12 species of Pteridophytes belonging to 8 genera and 6 families; and 80 species of Angiosperms belonging to 61 genera and 46 families were recorded. The existence and development of these plants indicated that human impact was little in the cave. The characters of the flora in Tongtianluo cave had much to do with the special ecological factors in it, i.e., the low illumination and calcareous clay soil.