Climate change‐induced migration patterns and extinction risks of Theaceae species in China

Abstract

Theaceae, an economically important angiosperm family, is widely distributed in tropical and subtropical forests in Asia. In China, Theaceae has particularly high abundances and endemism, comprising ~75% of the total genera and ~46% of the total species worldwide. Therefore, predicting the response of Theaceae species to climate change is vital. In this study, we collected distribution data for 200 wild Theaceae species in China, and predicted their distribution patterns under current and future climactic conditions by species distribution modeling (SDM). We revealed that Theaceae species richness is highest in southeastern China and on Hainan Island, reaching its highest value (137 species) in Fujian Province. According to the IUCN Red List criteria for assessing species threat levels under two dispersal assumptions (no dispersal and full dispersal), we evaluated the conservation status of all Theaceae species by calculating loss of suitable habitat under future climate scenarios. We predicted that nine additional species will become threatened due to climate change in the future; one species will be classified as critically endangered (CR), two as endangered (EN), and six as vulnerable (VU). Given their extinction risks associated with climate change, we recommended that these species be added to the Red List. Our investigation of migration patterns revealed regional differences in the number of emigrant, immigrant, and persistent species, indicating the need for targeted conservation strategies. Regions containing numerous emigrants are concentrated in Northern Taiwan and coastal regions of Zhejiang and Fujian provinces, while regions containing numerous immigrants include central Sichuan Province, the southeastern Tibet Autonomous Region, southwest Yunnan Province, northwest Sichuan Province, and the junction of Guangxi and Hunan provinces. Lastly, regions containing persistent species are widely distributed in southern China. Importantly, regions with high species turnover are located on the northern border of the entire Theaceae species distribution ranges owing to upwards migration; these regions are considered most sensitive to climate change and conservation planning should therefore be prioritized here. This study will contribute valuable information for reducing the negative impacts of climate change on Theaceae species, which will ultimately improve biodiversity conservation efficiency.

Large variability in response to future climate and land‐use changes among Chinese Theaceae species

“…This study was conducted in the entirety of China, which harbors ~46% (274 species) of total Theaceae species worldwide (Zhang et al, 2020 ). The occurrence records for the Theaceae species in the study area were obtained from the data set compiled and cleaned by Zhang et al ( 2020 ).…”

“…This study was conducted in the entirety of China, which harbors ~46% (274 species) of total Theaceae species worldwide (Zhang et al, 2020 ). The occurrence records for the Theaceae species in the study area were obtained from the data set compiled and cleaned by Zhang et al ( 2020 ). This data set contains 12,055 occurrence records for 200 Theaceae species, with the original species occurrence data collected from Chinese Virtual Herbarium ( http://www.cvh.ac.cn/ ) and the National Specimen Information Infrastructure ( http://www.nsii.org.cn/ ).…”

“…The family Theaceae forms a major component of tropical and subtropical ecosystems in Asia (Wu, 1995 ; Zhang et al, 2020 ). In China, it is also an important angiosperm family comprising about 12 genera and 274 species (Min & Zhang, 1996 ; Shen et al, 2016 ).…”

“…Besides, climate change is expected to exacerbate these current threats to Theaceae species. Species distribution models (SDMs) have predicted that most of Theaceae species will experience dramatic loss of their suitable habitat and some additional species will become threatened by 2070s (Zhang et al, 2020 ). Moreover, there is large variability among individual species' responses to future climate change (Zhang et al, 2020 ).…”

“…Species distribution models (SDMs) have predicted that most of Theaceae species will experience dramatic loss of their suitable habitat and some additional species will become threatened by 2070s (Zhang et al, 2020 ). Moreover, there is large variability among individual species' responses to future climate change (Zhang et al, 2020 ). However, an improved understanding of how the distribution of an individual species shifts under global change requires more detailed analyses by incorporating land use variables into climate SDMs (Prestele et al, 2021 ; Ramachandran et al, 2020 ), which has important implications for the protection of Theaceae species.…”