采用生态位模拟预测濒危植物白豆杉5个时期的适宜分布区

Suitable distribution of endangered species Pseudotaxus chienii( Cheng) Cheng( Taxaceae) in five periods using niche modeling

采用生态位模拟研究不同时期植物分布区变迁模式,有利于了解植物对气候变化的响应,从而更好地在全球气候背景下保护生物多样性。本研究以中国特有濒危裸子植物白豆杉(Pseudotaxus chienii)为对象,根据野外调查及标本记录确定34个野生分布点,结合5个时期(末次间冰期、末次盛冰期、中全新世、现在和未来)19个生物气候因子,运用生态位模型对5个时期白豆杉的潜在分布区进行重建。结果表明:白豆杉在5个时期的地理分布均与降水有密切关系,其中最干月份雨量是影响该物种分布最重要的气候因子,说明白豆杉适应潮湿气候和较短的旱季;在末次间冰期,白豆杉在中国东南呈大面积分布;在末次盛冰期,白豆杉分布区往浙江、福建和贵州东部扩张,江西、湖南等中部地区最适分布区面积减小;中全新世其适宜分布区面积比末次盛冰期有所减少,相比于末次间冰期其生境片段化更为严重;在未来气候变暖条件下,白豆杉适宜分布区减少,该物种往高海拔山地收缩,低海拔(约600 m以下)的适宜区基本消失。本文通过生态位模拟对白豆杉5个时期分布区进行重建,探究气候变化对其分布区变迁的影响,可以为保护濒危植物白豆杉提供有效依据。

Changes in the distribution of organisms throughout different geological times have been widely investigated by niche modeling.This knowledge is of great importance for biodiversity conservation in front of anthropogenic global warming.Pseudotaxus chienii(Cheng)Cheng is an endangered plant species scattered in southeast China.In this study,we reestablished its distribution ranges in five periods(Last Interglacial,LIG;Last Glacial Maximum,LGM;Mid-Holocene,MH;current and future)using 34 presence records by niche modeling based on 19 bioclimatic factors.The results showed that precipitation of driest month was the key bioclimatic factor affecting its distribution,suggesting that this species prefers a humid climate with a short dry season.During the LIG,P.chienii distributed widely in southeastern China.During the LGM,the distribution area of P.chienii expanded to Zhejiang,Fujian,the east of Guizhou,and the optimal distribution in the central China(Jiangxi and Hunan)decreased.During the MH,the optimal distribution area was decreased than that in the LGM,with more serious habitat fragmentation than that in LIG.In the future,the suitable distribution area of P.chienii will decrease under the predicted warming climate.The species will shrink to the higher elevations,and the suitable area of middle and low altitude(below 600 m)will disappear largely.Our results present an important insight into the response of P.chienii to climate changes,and provide a guideline for the conservation of this endangered species.