In order to understand effects of shading and pruning in lower canopy on Castanopsis hystrix, taking 2-year-old C. hystrix seedlings as test materials, different shading and pruning treatments were carried out on 1/3 lower canopy of C. hystrix seedlings, and indexes of plant height, ground diameter, biomass of different or-gans and photosynthetic characteristics were determined. Effects of shading and pruning in lower canopy on growths and photosynthetic characteristics of C. hystrix seedlings were studied. Results showed that with in-crease of shading degree, plant height and ground diameter showed trends of firstly increase and then decrease. Biomass of different parts in upper and lower canopies and total biomass showed trends of firstly increase and then decrease. Biomass allocation ratios of leaves in upper and lower canopies, and biomass allocation ratios of stems and above-ground parts in upper canopy showed trends of firstly increase and then decrease. Biomass al-location ratios of branches, stems and above-ground parts in lower canopy showed trends of decrease. Biomass allocation ratios of branches in upper canopy and roots and root to shoot ratio showed trends of firstly decrease and then increase. Net photosynthetic rate, stomatal conductance, transpiration rate and water use efficiency of leaves showed trends of firstly increase and then decrease. Intercellular carbon dioxide concentration showed trend of firstly decrease and then increase. Growth indexes, most of organ biomass and allocation ratios, and photosynthetic characteristics were higher in 45％shading and pruning treatments, and lower in both 70％and 85％shading treatments.
维普
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