Study On Growth And Development Of Plant In Subtropical Evergreen Broad-Leaved Forest

Evergreen Broad-leaved Forest is widely distributed in the subtropical part of east china. In order to understand the ecological trait of plant development in Evergreen broad-leaved forest. Typical plants were chosen as the study objects in Tiantong and Mt. Meihuashan. The bud style and fate, leaf phenology, leaf and branch growth, leaf lifespan and plant architecture were studied with the sampling and tracking method. The results were as follows:(1) The main style of bud in Mt. Meihuashan were scaled-bud and hypsophyllary-bud. In different life-form plant, median trees' bud were mainly scaled-bud, small trees' bud and shrub's bud were mainly hypsophyllary-bud. For median trees, the fate of bud in different layer were different, the fate of bud in upper layer were mostly amphoteric branch and vegetative bud, the fate of bud exist significant different in middle layer, the fate of bud in lower layer were mostly vegetative bud and un-actived bud. For shrubs, the fate of buds which growed in gap were amphoteric branch and amphoteric flower, the fate of buds which growed in shade were vegetative bud and un-actived bud. This indicate that plants which growed in gap mainly invest generative growth, plants which growed in shade mainly invest vegetative growth. The fate of bud also correlated with the branch length, the fate of bud which growed in short branch were un-actived bud, the fate of bud which growed in long branch were generative branch.(2) The beginning time of leaf emergence of most species in Mt. Meihuashan took place in later March and early April, ending time of leaf emergence took place in middle April. The more earlier of leaf emergence, the more earlier the leaf ending emergence. The later the leaf ending emergence, the longer the duration of leaf emergence. The beginning time of leaf emergence and ending time of leaf emergence of dominant species were earlier than companion species. The beginning time of leaf emergence and the ending time of leaf emergence of shrub were earlier than arbor. Leaf emergence pattern of most species were flushing pattern, according to the duration of flushing, flushing pattern can be categorized into short flushing type and long flushing type. Median trees were mainly short flushing type, shrub were mainly long flushing type.(3) The leaf expansion rate of 12 species in Tiantong was 12.5%, and the leaf expansion rate mainly range from 9.3%～13.4%. The leaf expansion rate of 36species in Mt. Meihuashan was 11.7%, and the leaf expansion rate mainly ranged in 6.4%～11.6%. Median trees' leaf expansion rate was the biggest. The leaf expansion of dominant species were bigger than companion species, the leaf expansion rate between Sun tolerant and shade tolerant species diden't exist significant different. The leaf growth tend present "S" growth style, that means that in early phases, leaf grow slowly, with leaf growth, expansion rate gradually grows quickly, in the later phases, leaf expansion rate gradually grows slowly and tend to a constant.The 36 species' branch growth rate was 0.24cm/d, branch growth rate mainly ranged from 0.03cm/d⁰.33cm/d. Median trees' branch growth rate was the biggest, the second was shrubs, the small trees was most smallest. Branch growth rate of Sun tolerant bigger than shade tolerant species. However, branch growth rate of dominant species smaller than companion species. The branch growth tend present half "S" growth style, this means that in early phases, branch growth relatively average speed, in the later phases, leaf expansion rate gradually grows slowly and tend to a constant. The branch and leaf growth existed two styles: branches achieve development earlier than leaves, branches and leaves achieve development simultaneously.(4) Schima superba seedling' angle of branch, angle of leaf, branch bifurcation ratio of order one and two, overall bifurcation ratio smaller than sapling. The angle of branch, angle of leaf, branch bifurcation ratio of order one and two, overall bifurcation ratio of Schima superba based in gap bigger than under forest, the longth of Schima superba branch positively correlated with the longth of node and the size of leaves.(5) The leaf lifespan of 51 evergreen broad-leaved species mostly ranged from 1 to 1.5 years and from 2 to 2.5 years. The leaf lifespan of shrubs were the longert, the next were median trees, the small trees were shortest, the leaf lifespan of dominant species were shorter than that of companion species, the leaf lifespan of sun plants were shorter than that of shade plants. The leaf lifespan of the one species became longer with the increasing of altitude. Leaf lifespan negatively correlated with specific leaf area(SLA), N_mass, the number of leaves and the leaf expansion rate.