热带海岸防护林带不同起源树种叶片—土壤的生态化学计量特征

Leaf and Soil Ecological Stoichiometric Characteristics of Tree Species of Different Origins in a Tropical Coastal Shelterbelt Belt of Hainan Island

[目的]探讨海南岛热带海岸防护林带不同起源树种叶片及土壤生态化学计量特征差异,为海岸防护林生态修复工作提供理论参考。[方法]采用样方调查的方法,调查了海南岛万宁市海岸线200 m范围内木麻黄、青皮、拉关木和水椰4个树种叶片和土壤C,N,P的生态化学计量特征。[结果]①不论是非红树还是红树植物,同一类型下,本土天然树种叶片C,N,P含量显著大于或等于外来人工种植树种,其中青皮叶片C,N,P含量分别为457.04,16.77和1.17 g/kg,均显著高于木麻黄;②从叶片养分变化特征来看,红树植物的生长可能受到N的限制;而非红树植物的生长可能受到P的限制;③从土壤养分变化特征来看,4种树种林地土壤N元素偏低,主要限制性元素为P。[结论]在海岸生态修复过程中,可以首选本土天然林树种作为海岸防护林种植优势树种。

[Objective]The objective of this study was to determine the differences in ecological stoichiometric characteristics of leaves and soil for different tree species of different origins in a tropical coastal shelterbelt of Hainan Island in order to provide a theoretical reference for the ecological restoration of coastal shelterbelts.[Methods]The ecological stoichiometric characteristics of C,N,and P in the soil and leaves of four species(Casuarina equisetifolia,Vatica mangachapoi,Laguncularia racemosa,and Nypa fructicans)within 200 m of the coastline of Wanning City,Hainan Island,were investigated by sampling method.[Results]①For both non-mangrove and mangrove plants,the C,N,and P contents of the leaves of native natural tree species were significantly greater than or equal to the C,N,and P contents of exotic artificial tree species.The C,N,and P contents of the leaves of Vatica mangachapoi were 457.04,16.77,and 1.17 g/kg,respectively,all of which were significantly higher than the values observed for Casuarina equisetifolia.②In terms of leaf nutrient change characteristics,the growth of water coconut and mangrove plants may be limited by N.However,the growth of casuarina and non-mangrove plants may be limited by P.③In terms of soil nutrient change characteristics,N was low and P was the main limiting element in woodland soil for the four tree species.[Conclusion]In the process of coastal ecological restoration,native natural forest species should be preferred as the dominant species for coastal protection forest planting.