Introduced non-native mangroves express better growth performance than co-occurring native mangroves

Fatih Fazlioglu,Luzhen Chen

doi:10.1038/s41598-020-60454-z

Abstract

Mangroves are salt-tolerant woody species occurring in tropical/subtropical coastal habitats. Plantation of fast-growing non-native mangrove species has been used as a tool for mangrove restoration/reforestation in several countries. However, the fast-growth ability can make recently introduced species invasive as they can possibly replace co-occurring native mangroves through expressing higher growth performance and phenotypic plasticity. Therefore, quantifying growth differences between native versus non-native mangrove species is important for forest ecology and management. In this meta-analysis, we compared the growth performance of non-native and native mangrove species pairs by analysing all available results in the literature (33 studies). We found that non-native mangrove species performed better than co-occurring native mangrove species in their introduced regions (Log response ratio = 0.51 ± 0.05) and they also expressed higher trait plasticity. Therefore, these species can be potentially invasive owing to their greater competitive advantage. However, the growth difference was diminished at higher latitudes where native mangrove species seem to perform as well as non-native mangrove species do. This is the first meta-analysis on the growth response of mangroves and it has consequential management implications. We suggest that planting of non-native mangrove species should be avoided and their spread should be monitored.

Highlights

Introduction yearReferencesmain reason for introduced species is accidental introductions[11]
There were 21 different combinations of non-native versus native mangrove species comparisons (Kandelia candel in China is recognized as Kandelia obovata13,62) (Appendix C)
High trait values in relative growth rate (RGR) and specific leaf area (SLA) are features of invasive tree species in the Mediterranean climate and these traits can be predictors of biological invasions[56]. We selected such key growth performance traits to assess the invasiveness potential of introduced mangrove species

Summary

Introduction

Introduction yearReferencesmain reason for introduced species is accidental introductions[11]. Many non-native woody species have been introduced into mangrove forests in North America, Australia and Africa[12,13,14,15,16] (see Table 1 for details). Invasive species in mangrove forests were found to prevent the establishment and growth of mangroves, alter existing native vegetation composition, prevent regeneration, and affect ecosystem functioning[11]. Hawaii had no native mangroves before the introduction of Rhizophora mangle in 190215, and currently, there are at least six mangrove species in the archipelago. These introduced mangroves might have displaced some plant species in wetlands (e.g., Batis maritime, Paspalum vaginatum, Hibiscus tiliaceus and Thespesia populnea)[18,19]

Methods

Results

Conclusion