Analysis of Adaptation Strategies of Four Woody Plants to the Extreme Environment of Tropical Coral Island Based on Functional Traits

Abstract:

In order to explore the adaptation strategies of suitable woody plants to the extreme environment of tropical coral islands, Nerium indicum, Melaleuca bracteata, Morus alba, and Heritiera littoralis were transplanted to tropical coral island from the nursery of Wenchang City, Hainan Province, the morphological and anatomical characteristics of leaves and physiological characteristics of resistance of plants in two places were compared. The result showed that compared with Wenchang, the specific leaf area (SLA) of Morus alba in tropical coral island increased significantly. There was no significant difference in ratio of palisade tissue to sponge tissue (P/S) of N. indicum, while P/S of other three plants decreased significantly. The chlorophyll content of N. indicum and Morus alba increased significantly, while that of Melaleuca bracteata and H. littoralis decreased significantly. The total antioxidant capacity (T-AOC) of N. indicum, Melaleuca bracteata and H. littoralis increased significantly, while that of M. alba decreased significantly. The free proline (Pro) content in N. indicum leaves decreased significantly, while that of Melaleuca bracteata, Morus alba and H. littoralis increased significantly. Therefore, in order to adapt to the tropical coral island habitat, Morus alba and N. indicum showed a strategy of "enhancing carbon assimilation potential and sustaining higher damage", while Melaleuca bracteata and H. littoralis showed a strategy of "improving resistance and reducing carbon assimilation potential".

Key words:Adaptive strategy;Tropical coral island;Functional trait;Habitat stress;Island plant