Prediction of potential suitable areas of Actinidia arguta in China based on Maxent model

Actinidia arguta is a large deciduous vine of genus Actinidia in Actinidiaceae family. According to Flora Reipublicae Populris Sinicae, this species is distributed from the most northern Amur River bank to the Wuling Mountains in southern Guangxi, but its suitable distribution range has not been defined. Due to its unique edible and medicinal value, the population of Actinidia arguta has decreased dramatically in recent years, therefore it has been listed as a locally protected species in Beijing, Hebei and Jilin provinces. In this study, Maxent model was used to predict the potentially suitable distribution range of Actinidia arguta in China, and the distribution suitability was evaluated. The results showed that the suitable distribution range of Actinidia arguta in China was about 3.01×10~6 km~2. The highly suitable distribution area of Actinidia arguta was mainly concentrated in the middle and low mountain areas of central Sichuan, southern Shaanxi, western Hubei and northwest Guizhou, presenting a circular distribution. Among those areas, Yunnan, Sichuan and Shaanxi provinces covered the largest area. Jackknife knife-cutting method was used to calculate the main environmental factors affecting the distribution of Actinidia arguta. The first four main factors, i.e. the wettest season precipitation(500-800 mm), average annual temperature(12.5-17.5℃), the coldest season precipitation(290-660 mm) and altitude(2000-2690 m), provided a significant contribution up to 79%. This paper offered theoretical basis for the in-situ and ex-situ conservation of Actinidia arguta. It was suggested that the highly and moderately suitable areas could be used for ex-situ conservation and cultivation, and the agricultural planting could be improved based on the suitable environment factors.