文献类型：期刊文献

英文题名：Effects of Shading on the Growth and Photosynthetic Fluorescence Characteristics of Castanopsis hystrix Seedlings of Top Community-Building Species in Southern Subtropical China

作者：Xue, Guangyu[1,2,3] Wu, Junduo[1] Zhou, Bingjiang[1] Zhu, Xueping[1,2] Zeng, Ji[1,2] Ma, Yue[1,2] Wang, Yanan[1,2] Jia, Hongyan[1,2,3]

第一作者：薛光宇;Xue, Guangyu

通信作者：Jia, HY[1];Jia, HY[2];Jia, HY[3]

机构：[1]Chinese Acad Forestry, Expt Ctr Trop Forestry, Pingxiang 532600, Peoples R China;[2]Guangxi Youyiguan Forest Ecosyst Natl Res Stn, Pingxiang 532600, Peoples R China;[3]Youyiguan Forest Ecosyst Observat & Res Stn Guangx, Pingxiang 532600, Peoples R China

年份：2023

卷号：14

期号：8

外文期刊名：FORESTS

收录：;EI(收录号：20233514644016);Scopus(收录号：2-s2.0-85168797844);WOS:【SCI-EXPANDED(收录号:WOS:001057305500001)】；

基金：This study was funded by the Special Fund for Basic Research Business Expenses of Central Public Welfare Research Institutes of the Chinese Academy of Forestry Sciences: Research on the Corresponding Mechanism of the Health Status of Precious Tree Species on Light Intensity(CAFYBB2021ZB002-1), the National Natural Science Foundation of China (31971655), and the Scientific Program Project of the Experimental Centre of Tropical Forestry, Chinese Academy of Forestry (RL2020-05).

语种：英文

外文关键词：shading; Castanopsis hystrix; biomass allocation; root characteristics; chlorophyll fluorescence characteristics

摘要：Castanopsis hystrix is a major community-building species in the top communities of southern subtropical China, with a high natural regeneration capacity. However, excessive logging and the introduction of exotic tree species have substantially reduced the area of natural forest patches of Castanopsis hystrix, and seedling regeneration is essential for the long-term continuation of Castanopsis hystrix populations. To explore the effects of light intensity on the seedling emergence and early growth of Castanopsis hystrix, shading experiments were conducted under four shading treatments (0%, 40%, 60%, and 80%). The growth, biomass accumulation, and distribution, the quality index of seedlings, the morphology and structure of the root systems of seedlings, and the leaf chlorophyll content and chlorophyll fluorescence properties of seedlings under different shading treatments were analyzed. The results displayed the following: (1) Shade intensity impacts growth of Castanopsis hystrix seedlings and biomass allocation, with optimal results observed at 60% shade, leading to the promotion of organic matter production in leaves and the limitation of stem growth. (2) Using a multi-indicator composite index, it was determined that seedling quality for Castanopsis hystrix peaks at 60% shade intensity. (3) Shade significantly impacts the morphology and structure of Castanopsis hystrix's root system, with most root characteristics peaking at 60% shade, indicating a substantial increase in root development compared to no-shade conditions. (4) The D-values indicated the most suitable shade intensity for seedling growth to be 60%, suggesting that Castanopsis hystrix seedlings are sensitive to light and excessive light can be detrimental to their growth. (5) The 60% shade treatment showed the maximum values of chlorophyll fluorescence characteristics and photochemical activity, with variations in energy conversion efficiency and dissipation reflected in parameters like photochemical burst coefficient (qP), photochemical burst coefficient (qN), the actual photometric yield of PSII under light acclimation (YII), and the maximum photosynthetic electron transport rate in photoinhibition (ETR), thereby supporting seedling growth and maintaining the normal function of photosynthetic organs. In conclusion, 60% shade treatment can effectively improve the growth and photosynthetic characteristics of Castanopsis hystrix seedlings and promote the accumulation of nutrient elements, ultimately promoting their growth.