Sprouting Characteristics In Tree Species Of A Montane Evergreen Broad-leaved Forest In The Ailao Mountains.

This paper dealt with the sprouting characteristics of mid-mountain humid evergreen broad-leaved forests in the Ailao Mountain, Yunnan Province. The tree species diversity, sprouting patterns of different species (the number of the ramets, the ratio of sprout individuals to non-sprout individuals, the position of the sprouts occurred, the height of stubs) and the caloric value of some species in a primary forest and a logged forest (20 years ago) were investigated. The results showed that:1. The values of tree species diversity and abundance in the two forest types did not show significant differences, indicating a restoration towards mature phase in the logged forest.2. Among seedling, aboveground sprouts and basal sprouts, the aboverground sprouts took the largest proportion.3. The sprout number and sprout ratio of Castanopsis rufescens, Lithocarpus xylocarpus and Camellia forrestii displayed the highest values.4. In the logged forest, the ramet number of the stubs shorter than 0.5 m was significantly greater than the stubs which were 1-2 m tall and taller than 2 m (α= 0.05). However there were no significant differences between stubs with different height classes in the primary forest. In the logged forest, the lowest position of the sprouts occurred (less than 1/10 of the main stem) had significantly more sprouts than other positions. In the primary forest, the lowest position of the sprouts occurred had significantly more sprouts than the positions between 0.5—0.9 of the main stems did.5. Linear equation of bark thickness relating to diameter at breast height of trees showed similar slope values in the sprouting species and in the seed regeneration species. This could be probably resulted from the lack of predictable fires in this area.6. The differences of caloric value between sprout regenerated and seed regenerated Castanopsis rufescens were significant. It could be because that the latter allocates much more caloric value to the seed production. However, other dominant species did not show significant differences between the caloric values of plant samples of sprout regeneration and seed regeneration.