Predictive Distribution and Habitat Suitability Assessment of Taxus chinensis Based on MaxEnt in Sichuan Province
LI Can;LIU Xian-an;WANG Juan;PENG Pei-hao;SHAO Huai-yong;College of Earth Sciences,Chengdu University of Technology;Key Laboratory of Geoscience Spatial Information Technology Ministry of Land and Resources,Chengdu University of Technology;Institute of Ecological Resources and Landscape,Chengdu University of Technology;College of Tourism and Urban-Rural Planning,Chengdu University of Technology;
The 201 localities of Taxus chinensis were selected as the underlying data source found in the second national survey of key wild plant resources in Sichuan. A total of 31 environmental variables were screened that affect the distribution of Taxus chinensis. The potential distribution areas of Taxus chinensis in Sichuan were designated and their suitability was evaluated by using the maximum entropy model( Max Ent) and the Arc GIS geographic information system. The results have indicated that(1) the most suitable area size for the growth of Taxus chinensis in Sichuan is 11 508. 750 89 km~2,accounting for2. 37% of the total area of Sichuan; the suitable area size for the growth is 13 340. 487 64 km~2,account-ing for 2. 75%; the relatively suitable area is 12 099. 527 38 km~2,accounting for 2. 49%; and the unsuitable area size is 448 368. 743 5 km~2,accounting for 92. 39%. The area which is the most suitable,suitable and relatively suitable for the growth of Taxus chinensis is mainly distributed at the edge of the mountain regions around the Sichuan Basin,such as Chaping Mountains,Longmen Mountains,Daba Mountains,Huaying Mountains,Dalou Mountains,Daxiangling Mountains and Qionglai Mountains;(2) Among the 31 environment variables which have influence on the distribution of Taxus chinensis,12 of them have the major impact. To be specific,these major variables are altitude,annual temperature,precipitation in July,the monthly mean diurnal tempereture range,the average temperature in the coldest month,the precipitation variation coefficient,the lowest temperature in coldest month,the slope,the solar radiation in March,the average temperature in July,the average temperature in the driest season and the average temperature in November;(3)The most suitable environment for Taxus chinensis is highly vegetated subtropical ravine comparatively warm climate of 7. 5 ℃ ~ 15 ℃ in annual mean temperature,and 7 ℃ ~ 10 ℃ in mean diurnal range,altitude of 1 000 meters ~ 2 400 meters,abundant 50 mm ~ 160 mm precipitation in July with a 50 ~ 75 variation coefficient,solar radiation of 11 000 KJ·m-2·d-1 to 12 200 KJ·m~(-2)·d~(-1).