Species Diversity, Stand Structure, and Species Distribution across a Precipitation Gradient in Tropical Forests in Myanmar

Inkyin Khaine,Euddeum Lee,Haenaem Kim,Li Yang,Hoduck Kang,Hyun Kyung Lee,Jieun Kim,Sun Mi Je,Hana You,Jihwi Jang,Jong Kyu Lee,Myeongja Kwak,Su Young Woo,Taeyoon Lee

doi:10.3390/f8080282

Abstract

An understanding of how species diversity, structural pattern, and species distribution vary across different environmental regions is crucially important for tropical ecology. In this study, we explored how these ecological parameters vary across various rainfall regions in the tropics with annual rainfall levels ranging from 843 to 2035 mm. Diversity, similarity, structure, and forest classification, and their correspondence with rainfall regions were tested. We found that species diversity, site class, and structural complexity increased with rainfall, with differences of 1000 mm having significant effects on diversity. The structure and heterogeneity of forests were higher in the high rainfall regions than the low rainfall regions. The forest structure was significantly correlated with rainfall, and the structure differed substantially where annual rainfall differed among sites by approximately 200 or 400 mm. Forests could be classified into two types according to whether they had high annual rainfall (1411–2035 mm) or low annual rainfall (843–1029 mm). In addition, the dominance of species changed noticeably from high- to low-rainfall regions, with Tectona hamiltoniana and Terminalia oliveri only being abundant in the low rainfall region. Species diversity and richness were significantly correlated with rainfall and average temperature. These findings will provide invaluable information for forest management and ecological phytogeography.

Highlights

Species diversity and stand structure are essential for forest biodiversity because trees provide the basic needs and habitat for other species [1,2,3]
To achieve the main goal of this study, we addressed two main questions: (1) do forest diversity and stand structure vary across different rainfall regions in the tropics; and (2) If so, how do the species distribution and stand structure of forests vary with different rainfall regions?
We found that the number of species was higher at high rainfall regions than the low rainfall regions, with site 1, which had the highest rainfall among the five sites, having the greatest species richness (1.5- and 3.4-fold higher than at sites 4 and 5, respectively, where the annual rainfall was approximately 1000 mm and 1200 mm lower) (Table 1)

Summary

Introduction

Species diversity and stand structure are essential for forest biodiversity because trees provide the basic needs and habitat for other species [1,2,3]. An understanding of the diversity and stand structure of forests is critical for climate change regulation because their manipulation can allow creation of forests that absorb more carbon dioxide [7,8]. Much attention has been given to biodiversity conservation and how biodiversity varies between different forest conditions [1,9], we still only have a limited understanding of how forest diversity and structure vary between different rainfall regions because such forests always occur in different regions with different climates [9,10,11,12].

Objectives

Methods

Results

Discussion

Conclusion