Bryophyte diversity on a tropical continental island (Hainan, China): potential vulnerable species and environmental indicators

Abstract

ABSTRACT Introduction. Tropical bryophyte diversity is threatened by habitat loss and climate change. Methods. We reinvestigated the bryophyte biodiversity of Hainan Island, a continental island off the south China coast, with an extensive literature survey focusing on specimen information, and additional field collections. Endemic and threatened species, as well as biodiversity hotspots were identified using latest available information. Key results. Eight endemic species were proposed as potentially vulnerable species; their conservation status needs further investigation. Regional species richness identified the central mountain range as the bryological hotspot on Hainan Island. Environmental heterogeneity-diversity analyses employing Ordinary Least Squares demonstrated that percentage area of nature reserves within each region, range of precipitation, and range of temperature had strong correlations with regional species richness variation. Precipitation variables had more significant correlation with species richness variation than temperature variables. Water availability was the most important climatic predictor for bryophytes. Within bryophyte groups, liverworts and mosses occupied slightly different ecological niches. Conclusions. Our results support tropical bryophytes as sensitive indicators to drastic climate changes. Their ability to respond to climatic changes will contribute greatly to comprehensive conservation strategies.