Effects Of Symplocos Setchuanensis Seedlings Plant Functional Traits Under Different Succession Stages In Phyllostachys Pubescens Forest

Because of the man-made and nature disturbance, there are some schistose communities of Phyllostachys pubescens forests in Mountain Jinyun. is an economical bamboo, creating a big wealth for human beings. However, the fact that The P. Pubescens was fighting for resources and space with other species gave rise to the simplicity of the community, the instability of the ecosystem structure and the imperfection of serving function. In the meantime, Symplocos setchuansis is one of the section of symplocos, an evergreen broad-leaved species, whose community is the superior of early succession stage of subtropical evergreen broad-leaved forest in the reservation of Mountain Jinyun. The superior species determined the structure, the environment development and the kind of community. The dynamic of superior species, therefore, can determine whether the succession goes well, and become an important indication of the succession.The plant functional trait (PFT) is referred to as one of plant fitness characteristics including plant-morphology, plant-physiology, and plant-phenology, which would affect plants growth, reproduction and the fitness of life. Therefore, it is an effective measure in the study of plant compatibility for it can objectively show whether the plants adapt to the environment, connecting environment, plant individuals and ecosystem organic function all together. Thus the study of the plant functional trait adjustment mechanism of S. setchuansis is needed, which is one of superior species of Subtropical evergreen broad-leaved forest early succession stage in different succession stages of P. Pubescens. The study is significant in the Adaptation mechanism of evergreen broad-leaved species, the renewed motive and the dynamic of succession. The results are the following:(1) The different succession stages, the dramatic changes in the species composition, ultimately lead to the difference among community environments, during the succession of the P. Pubescens forests to evergreen broad-leaved forests. The light environment of community’s influence decreased with the succession process, which resulted in a low light under canopy class. In the study of the soil environment, it shows that the Water content of soil decreased and the Bulk density of soil increased with the succession process, which is one of the characters of soil physical environment. Nevertheless, the amount of the entire soil chemistry environment dropped, such as the amount of PH, Organic matter, total N, available N, total P, available P, total K and available K. Due to this, the environment possessed less water content and nutrition, eventually resulting in great differences during different succession stages.(2)During the succession from the P. Pubescens forests to evergreen broad-leaved forests,, S. setchuansis seedlings, the early successional speciesm, turned their leaves into big and thin ones, lengthened and slender their petious, and enlarged its leaves, to gain more light to fit the change of environment, so that they could fit the light environment of different succession stages.(3) During the succession from the P. Pubescens forests to evergreen broad-leaved forests, S. setchuansis seedlings have changed their biomass strategy between the Assimilation organs and the non-assimilation organs to adapt to environment in different succession stages. On one hand, it decreased the biomass allocation proportion of youth leaves, and increased that of the elder leaves, which assisted in reducing the production cost of leaves and improving the efficiency of the elder leaves. On the other hand, it decreased the biomass of leaves, twigs and roots, and increased the allocation proportion of leaves and twigs, as a result of which,S. setchuansis seedlings can fit the different succession stages of P. Pubescens forests.(4) With the succession from the P. Pubescens forests to evergreen broad-leaved forests, the K content of leaves of S. setchuansis seedlings increased while the amount of N, P, K in roots and twigs dropped. Meanwhile, the contents of nutrient elements of different organs decreased, despite the fact that the contents increased with the age and diameter class. The reasons mentioned above helped to improve the efficiency of nutrient elements, and helped the optimal allocation of nutrient elements.(5) With the succession the P. Pubescens forests to evergreen broad-leaved forests, the amount of photosynthetic pigment such as chla, chlb of S. setchuansis seedlings grew, with the chla/chlb diminishing. At the same time, in order to fit different succession stages of P. Pubescens., the content of photosynthetic pigment in mature leaves enjoyed a greater amount, and the chla/chlb decreased. Consequently, this may improve the efficiency of photosynthesis in mature leaves to adapt to the environment of different stages.(6) What’s more, we drew the conclusion that P is the limiting factor in different succession process of P. Pubescens based on the content of soil P, the N/P of S. setchuansis leaves and the distinctiveness of Mountain Jinyun’ location.Based on the findings and inferences above, along with the succession from the P. Pubescens forests to evergreen broad-leaved forests, the change of their morphological and physiological PFT assisted in fitting the different succession process of P. Pubescens, which resulted in the survive in the different stage of succession, and provided the guarantee for the smooth progress of succession.