Mangroves in the mountains only have leaves on the treetops. What happened?

In order to better accept the sunshine and rain. Mountain mangrove is a special plant, belonging to mangrove family, which usually grows in mudflats or salt marshes in coastal intertidal zones. Unlike other plants, mangrove leaves are mainly distributed in the treetops. Mangroves in the mountains adapt to saline-alkali environment, and high salt content and dry climate will lead to limited plant growth. Secondly, the leaves of mangroves in the mountains have a high demand for light and water. They mainly grow at the top of trees and can better accept sunlight and rain.