Abstract:

The timber volume and important value index of plant species of tee layer in different land use stages of Daka and Ba-ka, Xishuangbanna were measured and studied. The results show that there is mutuality between timber volume and land manage-ment intensity. Timber volume of 3 -year fallow field only take 7.2% ofhoUyhiU, which was, considered as secondary forest in Daka.Furthermore, there was no timber volume of 2 - year fallow field in Baka. All indicated that resource degradation resulted from current slash - and - bum agriculture. Timber volume of natural forest which destroyed for building house only take 14.8% m Daka and 82.8% in Baka of holly hill that are well reserved by traditional custom. Resouree degradation was resulted from the increasing need of natural forest.

Key words: Land use stages, Dynamism of resource degradation, Agrobiodiversity assessment, Xishuangbanna