Acta Scientiarum Naturalium Universitatis Pekinensis ›› 2019, Vol. 55 ›› Issue (4): 699-708.DOI: 10.13209/j.0479-8023.2019.046

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Experimental Study on Ecological Restoration of Degraded Mangroves

SHEN Xiaoxue1, JIANG Lide2, TAO Jiawei3, YU Lingyun1, NIU Zhiyuan1, CHEN Zhiteng1, LI Ruili1,†   

  1. 1. School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055 2. CCCC-FHDI Engineering Co. Ltd, Guangzhou 510230 3. Shenzhen Foreign Languages School, Shenzhen 518083
  • Received:2018-07-17 Revised:2018-08-05 Online:2019-07-20 Published:2019-07-20
  • Contact: LI Ruili, E-mail: liruili(at)pkusz.edu.cn

退化秋茄林的补水修复实验研究

沈小雪1, 姜立得2, 陶佳伟3, 于凌云1, 牛志远1, 陈志腾1, 李瑞利1,†   

  1. 1. 北京大学深圳研究生院, 环境与能源学院, 深圳 518055 2. 中交第四航务工程勘察设计院有限公司, 广州 510230 3. 深圳外国语学校, 深圳 518083
  • 通讯作者: 李瑞利, E-mail: liruili(at)pkusz.edu.cn
  • 基金资助:
    广东省海洋科技攻关项目“广东省典型海湾红树林生态调查与生态保护模式研究”、深圳市科创委科技攻关项目(JSGG20170824 110218769)和侨城湿地项目(华娱合字2017 第65 号)资助

Abstract:

Taking Kandelia obovata forest as the research object, through periodical replenishment experiment, the improvement of physicochemical properties of the sediments and the plant physiological indicators were used to ascertain the repair effect of water supplemnet on K. obovata. The main results were as follows. 1) The water content, pH, salinity, total nitrogen and organic matter content of sediments in the hydration group were higher than those in the control group, indicating that water supplement improved the nutrient conditions and salinity of the sediment. 2) Water supplementation significantly increased net photosynthetic rate, water use efficiency, and chlorophyll a content (P<0.05), while decreased intercellular CO2 concentration, indicating that water replenishment effectively improved the photosynthesis status and promoted the absorption and transformation of light energy for K. obovata. 3) The maximum fluorescence efficiency (Fv/Fm) of the photosystem II (PS II) in the control group was significantly lower than 0.8 (common threshold), indicating that the degraded K. obovata forest was in the photoinhibitory state, while Fv/Fm was significantly increased after water supplementation (P<0.01), approaching 0.8, indicating a significant improvement in plant health status. 4) Water supplementation improved the photochemical efficiency of the PS II reaction center of K. obovate and significantly improved the imbalance of the excitation energy distribution between the two-optical systems. Moreover, water supplementation also effectively reduced the heat dissipation of the antenna pigments and made the distribution of light energy tend to be efficient, thus increasing the foliar photochemical utilization efficiency. In summary, periodic replenishment is an effective method for the rehabilitation of land-based degraded mangroves.

Key words: Shenzhen Bay, Kandelia obovata, water replenishment, chlorophyll fluorescence, photosynthetic parameters

摘要:

以陆化导致的退化秋茄林为研究对象, 通过周期性补水实验, 从沉积物的理化性质和植物生理指标的变化, 探明补水对秋茄成林的修复效果。主要结果如下: 1) 补水后沉积物的含水量、pH、盐度、总氮和有机质含量总体上高于对照组, 补水改善了沉积物的营养和盐度条件; 2) 补水修复显著提高植物的净光合速率、水分利用效率和叶绿素a 含量(P<0.05), 降低胞间CO2浓度, 有效地改善退化秋茄林的光合作用状态, 增强秋茄叶片吸收和转化光能的能力; 3) 对照组植物光系统Ⅱ(PS Ⅱ)最大荧光效率(Fv/Fm)显著低于0.8 (常用阈值), 说明陆域化的秋茄林已处于光抑制状态; 但补水后Fv/Fm显著提高(P<0.01), 接近0.8, 说明植物健康状态得到显著改善; 4) 补水提高秋茄叶片PS Ⅱ反应中心的光化学效率, 显著改善双光系统间激发能分配的失衡状态, 有效降低天线色素热耗散, 光能分配趋于高效, 提高了叶片光能的光化学利用效率。研究结果表明, 周期性补水是陆域化的退化红树林生境改善的有效修复方法。

关键词: 深圳湾, 秋茄, 补水修复, 叶绿素荧光, 光合参数