孑遗植物滇桐在云南省的潜在适生区研究

The Potential Suitable Area of The Relic Plant Craigia yunnanensisin Yunnan Province

为明确全球气候变化的背景下滇桐的潜在适生区变化及深化对其变化机制的认识,基于云南21个滇桐种群分布点和12个气候变量,运用MaxEnt模型和GIS技术模拟滇桐在云南的潜在地理分布格局,并分析主导生物气候因子。结果表明:(1)预测模型的受试者工作特征曲线面积(训练AUC值)为0.995,显示高度准确性。(2)滇桐在云南的潜在适生区面积约为23.32×104km2,主要分布在文山、普洱、保山、德宏和怒江等地。(3)影响滇桐分布的主导环境因子依次为植被类型(29.8%)、温度季节性(21.1%)、等温性(15%)和海拔(13.5%),累积贡献率达79.4%;其最适宜区间中,植被类型为栽培植被、草丛和灌丛,温度季节性为4.0~4.8℃,等温性为44%~50%,海拔为1 300~2 200 m,最冷月最低温度为1.0~6.0℃。(4)滇桐主要适生区主要植被型组包括栽培植被、阔叶林、草丛、针叶林和灌丛,其中栽培植被型面积最大,占比29.22%;主要适生区土地利用类型以灌木林为主,占比24.92%。研究结果为滇桐的引种栽培、天然分布地的长效保护、发掘和利用提供参考。

To clarify the potential habitat changes of Craigia yunnanensis W.W.Smith&W.E.Evans and deepen the understanding of its change mechanism under the context of global climate change,using 21 population distribution points in Yunnan and 12 climate variables,the MaxEnt model and GIS technology were applied to simulate the potential geographical distribution pattern of C.yunnanensis in Yunnan under current climate scenario,and dominant bio-climatic factors were analyzed.The results found that:(1)The area under the receiver operating characteristic curve(training AUC value)was 0.995,indicating high accuracy of the prediction model.(2)The potential suitable area of C.yunnanensis in Yunnan was approximately 233200 km 2,mainly distributed in Wenshan,Pu’er,Baoshan,Dehong and Nujiang.(3)The dominant environmental factors affecting its distribution were Vegetation type(29.8%),temperature seasonality(21.1%),temperature uniformity(bio3,15%),altitude(Alt,13.5%),with a cumulative contribution rate of 79.4%.(4)The most suitable intervals for these factors were,for Veg:cultivated vegetation,grass and shrub;for temperature seasonality:4.0-4.8℃;for temperature uniformity:44%-50%;for Alt:1300-2200 m;The main potential habitats included cultivated vegetation,broad-leaf forests,grasslands,coniferous forests,and shrublands,with cultivated vegetation type covering the largest area,accounting for 29.22%;and land use types in the potential habitat were primarily shrublands,comprising 24.92%.The findings provide a basis for the introduction and cultivation of C.yunnanensis,the discovery of its natural habitats,and the avoidance of risk areas.Moreover,they offer scientific evidence for the climate environment control in artificial cultivation,as well as the long-term protection and utilization of the species.