东寨港和淇澳岛红树林区地表高程和沉积层厚度变化的测量与研究

Measurement and Study on Variations of Surface Elevation and Accretion Thickness of Areas of Mangrove Forests in Dongzhaigang Bay and Qi’ao Island

引进并利用地表高程-水平标志层(rod surface elevation table-marker horizon,RSET-MH)测量体系,以海南省海口市东寨港和广东省珠海市淇澳岛的红树林区为研究区,对比了不同林分下红树林区的地表高程和沉积层厚度变化的差异。研究结果表明,与2018年6月相比,2020年6月,东寨港原始红树林区和恢复红树林区的地表高程分别降低了(3.41±2.11) mm和(3.12±0.97) mm,淇澳岛泥滩区的地表高程降低了(82.12±5.12) mm,淇澳岛林缘区和林内区的地表高程分别升高了(59.38±8.17) mm和(69.24±4.41) mm;东寨港原始红树林区和恢复红树林区的沉积层厚度分别增大了(20.43±2.15) mm和(42.12±3.14) mm,淇澳岛林缘区和林内区的沉积层厚度分别增大了(30.01±4.19) mm和(60.31±3.41) mm;不同林分红树林区的地表沉积层厚度变化和浅部下沉量差异显著,提示沉积层厚度受多种因素的影响,地表浅部变化也在很大程度上决定着地表高程的变化量;红树具有抵抗地表浅部下沉的能力,这与其根系的生长量大于分解量有关。本研究在红树林区地表高程观测中引进、利用了RSET-MH体系,建立了红树林潮滩沉积速率与地面高程变化速率的检测网络,可以为研究红树林区地表高程的变化规律和加强红树林保护提供科学依据和技术支持。

The surface elevation table-marker horizon(RSET-MH) system was introduced to investigate variations of surface elevation and accretion thickness of areas of mangrove forests in Dongzhaigang Bay,Hainan and Qi’ao Island, Guangdong, China. The results showed that from June 2018 to June 2020, the decreases of surface elevation at the areas of original and restored mangrove forests in Dongzhaigang Bay were up to(3.41±2.11) mm and(3.12±0.97) mm separately. The variations of surface elevation at the areas of the mud flat, the edge and inner of mangrove forests in Qi’ao Island were(-82.12±5.12) mm,(59.38±8.17)mm and(69.24±4.41) mm, respectively. The significant changes of surface elevation and accretion thickness were found between different areas of mangrove forests, which indicated sedimentation was affected by various factors. The variation of surface elevation was also determined by shallow subsidence. Mangrove trees has ability to resist shallow subsidence, which is related to the growth of the roots. In this study, RSETMH was introduced to investgate surface elevation of the areas of mangrove forests. The monitoring system for the changes of surface elevation in the areas of mangrove forests was also established.