基于MaxEnt模型的小黄花茶在中国的适生区域研究

Study on the suitablearea of Camellia luteoflora Y. K. Li in China based on MaxEnt model

摘要:

珍稀植物小黄花茶（Camellia luteoflora Y. K. Li）在自然分布区内数量缩减，存在濒临灭绝的风险.为分析当前气候环境条件下小黄花茶的潜在适宜分布区，本研究运用最大熵（MaxEnt）生态位模型和地理信息系统(ArcGIS)软件对小黄花茶在我国的适生区进行预测，探讨影响其分布的主要环境因子.结果显示，四川泸州、宜宾，贵州遵义，云南昭通、昆明以及重庆江津、綦江是小黄花茶的高度适生区（适生指数＞0.54），黔、川、渝交界处是其核心分布地.刀切法（Jackknife）检测结果表明，影响小黄花茶分布区的主要环境因子包括最热季平均气温（Bio10）、最热季降水量（Bio18）以及最冷季降水量（Bio19），累计贡献率高达90.8%.适生区环境因子的统计分析结果显示，最热月最高气温为22.5~27.5 ℃，最热季平均气温为11.1~180 ℃，最湿月降水量为290~500 mm，最热季降水量为4.4~6.6 mm，最冷季降水量为16.7~24.8 mm，海拔为450~1 000 m，坡向在-40°~190°范围内，而坡度在20°~64°之间是小黄花茶最适宜生长的生态位参数.本次研究预测了小黄花茶适生区，除已知报道的三处自然分布区外，预测结果显示可能还存在尚未发现的小黄花茶生长地，有待进行实地勘测.

Abstract:

The rare plant Camellia luteoflora Y. K. Li has shrunk in the natural distribution area and is at risk of extinction. In order to analyze the potentially suitable distribution area of C.luteoflora under the current climate and environmental conditions, Maximum Entropy Model (MaxEnt) and Geographic Information System (ArcGIS) were used to predict the suitable distribution areas of C.luteoflora and to explore the dominant environmental factors. The results show that Luzhou, Yibin, Zunyi, Zhaotong, Kunming, Jiangjin and Qijiang of Chongqing are the highly suitable areas for C.luteoflora (fitness index>0.54), and the junction of Guizhou, Sichuan and Chongqing is its core distribution area. The results of the jackknife test showed that the main environmental factors affecting the distribution area of C.luteoflora included the average temperature of the hottest quarter (bio 10), the precipitation of the hottest quarter (bio 18) and the precipitation of the coldest quarter (bio 19), with a cumulative contribution rate of 90.8%. The results of statistical analysis of environmental factors in the suitable area show that the highest temperature in the hottest month is 22.5~27.5 ℃, the average temperature in the hottest season is 11.1~18 ℃, the precipitation in the wettest month is 290~500 mm, the precipitation in the hottest season is 4.4~6.6 mm, the precipitation in the coldest season is 16.7~24.8 mm, the altitude is 450~1 000 m, the slope direction is in the range of -40°~190°, and the slope is between 20°~64°, which is the most suitable niche parameter for C.luteoflora. In addition to the three reported natural distribution areas, the prediction results show that there may still be undiscovered growth areas of C.luteoflora, and field surveys are needed.