Propagules And Regeneration Of Karst Semi-Humid Evergreen Broad-Leaved Forest In Central Yunnan

Propagation and regeneration is an old but unfailing research topic. Many ecologists and botanists keep stick to this area continuously in identifying propagule types, propagation and regeneration strategies of different species in their respect ecosystems in different areas of the world. Karst is a typical landscape form in China. Though karst vegetation disappears and degrades in very high rate recently, little is know on propagation and regeneration of plants growing on this karst matrix. Research on this area will provide scientific bases for any action on conservation and restoration of karst vegetation. This research is carried out at a semi-humid evergreen broad-leaved forest (SEBF), two young regenerated forests and several degraded ecosystems in karst area in central Yunnan. With results from vegetative species composition, seed rain, soil seed bank, seedling and sapling bank, sprouts and clones, and results from seed burial, limiting factors determination on seedling germination in the forest, an attempt is given to classify the type of propagule and regeneration strategies of species, to quantify the number of propagule, to identify limiting factors and finally, and to evaluate the regeneration status of current forest.Seed is the major propagule type in karst area in central Yunnan. Other types, including woody stools that can sprout and clone, herb roots and underground stems that can clone were also identified. About 1/3 of woody individuals sprout in various degrees in three karst forest. However, cloning evidences for woody species were only determined in species Neolitsea homilantha and Olea yunnanensis. Many herb species persists cloning propagule, such as tiller and rhizome (Gramineae and Cyperaceae species), tubers (potato) and bulbil (Liliaceae species). They can clone new individuals that are the same genetic status with their mother plants. With adaptation in long history, many tree and shrub species, especially constructive species- Neolitsea homilantha, Olea yunnanensis and Pistacia weinmannifolia develop capability to depend upon karst matrix. They grow on the protection of surrounding rock gaps, rock ditches or rock slots and then escape root damage from disturbance of animals and human, and from fuel wood collection. Some stools can stand on repeat disturbance and persist on the...