基于Maxent模型的檵木分布格局模拟

应用最大熵模型（Maxent）模拟檵木（Loropetalum chinense）在末次间冰期（last inter glacial，LIG）、末次盛冰期（last glacial maximum，LGM）和当代（Present）等不同时期的中国潜在分布格局，分析影响其分布的主导生物气候因子。结果显示：（1）历史气候的变迁，檵木由末次间冰期经末次盛冰期进入当代，适生区面积呈现增加趋势。当代适生区面积占比最大，适生程度也较高；（2）训练数据和测试数据的AUC值分别为0.947和0.954，均达到了极高的精度；（3）刀切法检测表明，影响檵木分布的主导环境因子依次为bio14（最干月份平均降雨量）、bio17（极干季降雨量）、为bio19（极冷季平均降雨量）和bio15（湿度变化方差），其适生值范围分别是23-93 mm，98-300 mm，110-350 mm和42%-65%；（4）较纬度而言，经度是影响我国檵木分布格局的主要因子；（5）我国檵木当代的潜在地理分布主要在北回归线以北的区域，总面积为162.55万km²，占国土总面积的16.93%，高适生区集中于广西北部、江西东部、以及湖南南部、福建东部等地区。本研究较为准确地模拟了檵木在3个不同时期的适生分布，为深入分析檵木现代分布格局的形成提供科学依据。

Prediction of distribution area of Loropetalum chinense based on Maxent model

The maximum entropy model (Maxent) was used to simulate the potential distribution areas of Loropetalum chinense in China in different periods such as the last inter glacial (LIG), the last glacial maximum (LGM) and the present. Key biological factors affecting Loropetalum chinense distribution were analyzed. The results showed that: (1) the change of historical climate from the last inter glacial period to the last inter glacial, and then to the present, the suitable area of L. chinense increased. The proportion of present suitable area was the largest, and the suitable degree was also higher. (2) the area under the curve(AUC) values of training data and test data were 0.947 and 0.954, respectively, which had reached a very high precision. (3) the dominant environmental factors affecting the distribution of L. chinense by Jackknife testing showed that bio14 (Precipitation of Driest Month), bio17 (Precipitation of Driest Quarter), bio19 (Precipitation of Coldest Quarter) and bio15 (Precipitation Seasonality) successively. The range of suitable value was 23-93 mm, 98-300 mm, 110-350 mm and 42%-65%, respectively. (4) Compared with the factor of latitude, the longitude was main factor affecting the distribution area of L. chinense in China. (5) The potential geographical distribution of the L. chinense in China was mainly in the north to the Tropic of Cancer, with a total area of 162.55 million km², accounting for 16.93% of the national territorial area. The highly suitable areas were mainly in the north of Guangxi, the east of Jiangxi, the south of Hunan and the east of Fujian Province. This study accurately simulated the suitable distribution of L. chinense in three different periods, and provided scientific basic for analyzing the formation of modern distribution of L. chinense.