基于MaxEnt模型预测四川省松材线虫的潜在适生区

Prediction of the Potential Distribution of Bursaphelenchus xylophilus in Sichuan Province Using MaxEnt Model

松材线虫Bursaphelenchus xylophilus是我国重要的林业检疫性有害生物之一,由其引发的松材线虫病已造成巨大的经济损失,严重阻碍了林业的健康发展。研究并明确松材线虫在四川省的潜在适生区,对四川省有关部门制定该病害的早期监测、预警及防控具有一定的参考意义。本文基于2009—2018年四川省林业有害生物普查数据中松材线虫病和松墨天牛Monochamus alternatus的实际地理分布数据(松材线虫病:n=208,松墨天牛:n=803)及19个环境变量数据,利用MaxEnt模型和Arc GIS对松材线虫在四川省的潜在分布区进行预测,并用ROC曲线分析法检测模型模拟精度、用刀切法检测变量的重要性及其适宜值。结果表明:松材线虫在四川省的潜在最佳适生区主要分布在宜宾市、广安市、达州市、自贡市、西昌市,以及乐山市和眉山市的交界区,面积为36 541 km^2;影响松材线虫分布的主要环境变量为最干季均温(适值范围1. 5～8. 0℃,最适值6. 4℃)、季节性降水变异系数(适值范围22. 5%～34. 0%,最适值34. 0%)、最冷月最低温(适值范围0. 4～2. 5℃,最适值1. 9℃)、海拔(适值范围250～5 500 m,最适值450 m)、年温差(适值范围5. 9～9. 1℃,最适值5. 9℃)和年降水量(适值范围64～135 mm,最适值68 mm)。

Pine wood nematode( Bursaphelenchus xylophilus) is one of the hazardous forestry quarantine pests in China,and the pine wilt disease caused by this species has brought great economic loss and hindered the development of forestry health seriously.To monitor and control pine wilt disease in Sichuan province,we survey the potential distribution area of B.xylophilus based on the geographic distribution data( B.xylophilus: n = 208,Monochamus alternatus: n = 803) and 19 bioclimatic data accessed to the Sichuan Forestry Department,and the potential distribution of B.xylophilus in Sichuan province was predicted by MaxEnt and Arc GIS.Meanwhile,the receiver operating characteristic was used to test the simulation precision,and the"Jackknife"method was conducted to determine the importance of the environmental variables.The results showed that the highly suitable areas for B.xylophilus were Yibin,Guang’an,Dazhou,Zigong,Xichang,and the ecotone of Leshan and Meishan cities,and the area was 36 541 km^2.The important environmental variables affecting the distribution of B.xylophilus were the mean temperature of the driest season( the range is 1.5-8.0 ℃,the optimal is 6.4 ℃),the seasonal precipitation coefficient of variation( the range is 22.5%-34.0%,the optimal is 34.0%),the lowest temperature of the coldest month( the range is 0.4-2.5 ℃,the optimal is 1.9 ℃),the elevation( the range is 250-5 500 m,the optimal is 450 m),the annual temperature range( the range is 5.9-9.1 ℃,the optimal is 5.9 ℃),and the annual precipitation( the range is 64-135 mm,the optimal is 68 mm).