Plant key functional traits in species adaptation and screening for vegetation restoration on coral islands.

Abstract

Plant functional traits and trial-error method have been used successfully in suitable species screening for vegetation restoration on tropical coral island ecosystems. However, there remains controversy about which functional traits should be used as key indicators for plant screening, and the feasibility of classifying plant types through functional traits. Here we determined 25 structural and physiological traits of a total of 56 plant species in a tropical mainland nursery and a tropical coral island, comparing differences of each trait between the two habitats. We attempted to study plant adaptations based on restoration needs and life forms, and then selected suitable species based on key functional traits related with survival performance. We found that leaf thickness, plant height, palisade and spongy tissue thickness, were four key traits in future tropical coral island restoration species screening, and listed nine suitable species from our species pool. Contrary to nursery plants employing the acquisitive strategy under sufficient resources, island plants featured more resilient leaf structure and higher antioxidant capacity, exhibiting a tolerance strategy to better cope with stresses. Meanwhile, plant functional traits rather than restoration needs or life forms are more fundamental in studying species adaptation. Plants adjusted traits from growth to tolerance strategy in the harsh island habitat, and using key functional traits is an accurate and efficient way for screening suitable species in the revegetation of degraded tropical coral islands.