基于MaxEnt模型研究气候变化对巴戟天适生分布的影响

Climate Change Effects on Suitable Area Distribution of Morinda officinalis by MaxEnt Model

关键词:  巴戟天  潜在地理分布  MaxEnt模型  气候变化  环境因子

Key words:  Morinda officinalis  potential geographical distribution  MaxEnt model  climate change  environmental factors

摘要:

巴戟天（Morinda officinalis）的肉质根是我国著名的四大南药之一，具有较高的经济和药用价值。本研究收集了25个巴戟天有效分布信息，结合气候、地形、土壤等38个环境因子，运用最大熵（MaxEnt）模型和地理信息系统（ArcGIS），对巴戟天当前（1970-2000）及未来2050s （2041-2060）3种气候情景下（SSP1-2.6、SSP2-4.5、SSP5-8.5）的潜在地理分布进行预测，并根据贡献率及响应曲线综合评判影响巴戟天分布的主导环境因子。结果表明：（1）MaxEnt模型预测精度高，4种气候情景下的Area Under Curve （AUC）值均大于0.985。（2）对巴戟天分布贡献率较大的主导环境因子有4个，分别是最冷季度降水量（47.4%）、年平均气温（28.9%）、年降水量（10.0%）、平均气温日较差（1.7%），最适宜巴戟天生长的生态位参数分别是156.8 mm、21.8 ℃、1 857.1 mm、6.4 ℃。（3）当前巴戟天的潜在适生面积合计83.59×10⁴ km²，主要分布在广东、广西等热带、亚热带地区，高适生区集中在广东（肇庆、云浮、惠州、河源）、广西（玉林、贵港、防城港）、台湾（花莲、台中）、海南（保亭、陵水）等地。未来气候情景下巴戟天潜在地理分布总体收缩，低适生区变化较为明显，中、高适生区相对稳定。（4）随着气候变暖，未来气候情景下巴戟天潜在适生分布呈现“西扩”与“东缩”的趋势，适生区由东向西迁移，云南西南部是主要增加区。适生区分布研究结果可为巴戟天栽培区域选择提供参考。

Abstract:

The fleshy root is one of the four famous southern medicines in China, with high economic and medicinal value. We utilized the MaxEnt model and ArcGIS to predict the potential geographical range of M.officinalis in current climate (1970-2000) and three climate scenarios (SSP1-2.6, SSP2-4.5, SSP5-8.5) for the future 2025s (2041-2060), based on its distribution records of 25 valid specimens and 38 environmental factors including climate, topography and soil.The dominant environmental variables that affect the distribution of M.officinalis were comprehensive evaluated according to the results of the contribution rates and response curves.The results showed:(1) The MaxEnt model exhibited high prediction accuracy, with AUC values greater than 0.985 for all four climate scenarios.(2) Four dominant environmental variables that contributed significantly to the distribution of M.officinalis were precipitation of coldest quarter (47.4%), annual mean temperature (28.9%), annual precipitation (10.0%), mean diurnal range (1.7%); among which, parameters of the ecological niche best suited for the growth of M.officinalis are 156.8 mm, 21.8℃, 1 857.1 mm, and 6.4℃, respectively. (3) The current potential suitable habitat area for M.officinalis is estimated to be 83.59×10⁴ km².It is mainly distributed in Guangdong, Guangxi and other tropical and subtropical areas, with high suitable area concentrated in Guangdong (Zhaoqing, Yunfu, Huizhou, Heyuan), Guangxi (Yulin, Guigang, Fangchenggang), Taiwan(Hualien, Taichung), Hainan (Baoting, Lingshui) and ect.The suitable habitat distribution of M.officinalis will be contraction in all three future climate scenarios.Distribution changes are more pronounced in the low suitable area and relatively stable in the medium and high suitable area. (4) In the context of global warm, the suitable area of M.officinalis generally shows a trend of "Westward expansion" and "Eastward contraction".Suitable areas are migrating from east to west, with southwestern Yunnan being the main increase area.The results of this study on the distribution of suitable areas can provide references for the selection of cultivation areas for M.officinalis.