基于MaxEnt模型预测气候变化下厚叶木莲在中国的潜在地理分布

Predicting the Potential Geographical Distribution of Manglietia pachyphylla in China under Climate Change based on MaxEnt Model

关键词:  厚叶木莲  潜在地理分布  MaxEnt模型  气候情景

Key words:  Manglietia pachyphylla  potential geographical distribution  MaxEnt model  climate scenario

摘要:

厚叶木莲（Manglietia pachyphylla）是中国特有的极小种群野生植物，目前仅在广东和广西有少量居群，被列入国家Ⅱ级重点保护野生植物，研究其潜在地理分布有重要意义。本研究基于标本记录和野外调查数据，结合56个环境因子，应用MaxEnt模型模拟现代（1970-2000年）和3种未来（2021-2060年）气候情景下厚叶木莲在中国的潜在地理分布。结果表明：（1）MaxEnt模型模拟精度极高，受试者工作特征曲线下面积（Area Under ROC Curve，AUC）值为0.978；厚叶木莲现代潜在适生区集中分布于广东、海南、台湾、广西、福建及江西的大部分地区，在云南南部、湖南东部和西藏东南部等地也有分布。（2）对厚叶木莲的分布贡献率较大的主要生态因子有6个，分别是旱季平均温度（23.6%）、年平均降水量（22.7%）、下层土壤盐基饱和度（16.9%）、下层土壤碎石体积百分比（12.1%）、下层土壤质地分类（9.1%）和最冷月最低温度（7.3%）。其中，旱季平均温度20-25 ℃、年平均降水量3 500-4 500 mm和酸性砾质土是最适宜厚叶木莲生长的生态位参数。（3）现代厚叶木莲适生区面积合计67.07万平方千米，约占中国陆地面积的7%，低、中、高适生区分别占适生区总面积的69.3%、26.4%和4.3%；2021-2060年，在不同气候情景下，厚叶木莲适生区面积存在分化。在SSP126和SSP585气候情景下，厚叶木莲适生区面积均收缩；在SSP245气候情景下，其适生区面积则有较大幅度扩张。（4）2041-2060年，在SSP585气候情景下，当前气候条件下分布于广东中部和西部、广西西南部及海南中部的厚叶木莲高适生区全部消失。因此，建议广东江门古兜山省级自然保护区、北峰山国家森林公园等机构加大对厚叶木莲的保护力度，并开展其种苗培育和引种驯化相关工作。

Abstract:

Manglietia pachyphylla is a very small population of wild plants endemic to China, with a small number of populations only in Guangdong and Guangxi, and it is listed as a key wild plant under national protection of Class Ⅱ, which makes it more meaningful to study its potential geographic distribution.The MaxEnt model was used to simulate the potential geographical distribution of M.pachyphylla in China under modern (1970-2000) and three future (2021-2060) climate scenarios, based on existing distribution samples and field survey data and 56 environmental factors.The results showed that:(1) the simulation accuracy of MaxEnt model is very high, and the Area Under ROC Curve (AUC) value is 0.978; Modern potential suitable areas for M.pachyphylla are mainly distributed in Guangdong, Hainan, Taiwan, Guangxi, Fujian and most parts of Jiangxi, as well as southern Yunnan, eastern Hunan and southeastern Tibet.(2) There are six major ecological factors contributing significantly to the distribution of M.pachyphylla.The average temperature in the driest quarter (23.6%), the average annual precipitation (22.7%), the base saturation of the underlying soil (16.9%), the volume percentage of the underlying soil gravel (12.1%), the subsoil texture classification (9.1%) and the minimum temperature in the coldest month (7.3%).The most suitable niche parameters for M.pachyphylla were the average temperature of 20-25℃, the average annual precipitation of 3 500-4 500 mm and the acidic gravel soil.(3) The suitable area of M.pachyphylla was 670 700 km², accounting for about 7% of China's land area.The suitable area of low, medium and high M.pachyphylla was 69.3%, 26.4% and 4.3% of the total suitable area, respectively.From 2021 to 2060, the suitable area M.pachyphylla was differentiated under different climate scenarios.The suitable area of M.pachyphylla contracted under SSP126 and SSP585 climate scenario, while the suitable area expanded significantly under SSP245 climate scenario.(4) From 2041 to 2060, under the SSP585 climate scenario, comparing with under the current condition, the high suitable areas of M.pachyphyllum distributed in central and western Guangdong, southwest Guangxi and central Hainan have all disappeared.It is suggested that Gudou Mountain Nature Reserve of Jiangmen and Beifeng Mountain National Forest Park in Guangdong should strengthen their protection, and carry out seedling cultivation, introduction and domestication.