ADAPTATION OF LANDSCAPE PLANTS FOR INTRODUCTION IN THE ISLANDS BASED ON LEAF-LEVEL PHYSIOLOGICAL PLASTICITY

Abstract

Purpose Island ecosystem degradation is a global challenge, and plant introductions and soil amendments are effective measures to improve island ecosystems. However, few studies focused on the physiological adaptations of landscape plants introduced to islands.

Materials and methods Therefore, we tested the physiological responses and elemental properties of four landscape plants (Nerium oleander, Ruellia simplex, Acacia auriculiformis, and Mimosa pudica) from the Guangzhou-Sansha gradient (GZ, Guangzhou City; SS1, Paracel Islands, Sansha City, after garden soil amendment; SS2, Paracel Islands, Sansha City) in China.

Results Results revealed that differences existed in the adaptation of four landscape plants for introduction in the Islands. Among the four plants, N. oleander had the best adaptation to the Paracel Islands, while N. oleander and A. auriculiformis showed significant advantages in the leaf elemental characterization of Paracel Islands. Compared with GZ, SS1 and SS2 treatments reduced leaf carotenoid content (16.77%-68.92% and 30.64%-80.27%), chlorophyll-a content (29.45%-78.43% and 45.04%-85.62%), chlorophyll-b content (30.62%-77.40% and 43.87%-83.01%), and total chlorophyll content (79.41%-93.23% and 82.33%-94.91%) of the four plants, respectively. Then, SS1 and SS2 treatments significantly decreased the leaf N content, C:P ratio, and N:P ratio of N. oleander and R. simplex compared to GZ. Besides, compared with SS2 treatment, SS1 treatment maximized four plant’s leaf carotenoid, chlorophyll-a, chlorophyll-b, total chlorophyll, Ca, P, and water content by 1.40%-57.72%, 18.93%-50.00%, 15.62%-37.06%, 17.87%-44.28%, 5.68%-37.25%, 0.80%-103.86%, and 3.30%-10.31%, respectively.

Conclusions In conclusion, these findings underscore the potential of garden soil-amended coral soil in augmenting plant physiological adaptability, providing valuable insights for sea island soil improvement, and judicious introduction of optimal landscape plants.