濒危植物裸果木(Gymnocarpos Przewalskii)在新疆的潜在地理分布研究
Potential Geographical Distribution of Endangered Plant (Gymnocarpos Przewalskii) in Xinjiang

荒漠植物作为戈壁、沙漠地区的主要生物种质资源,是荒漠生态系统的重要组成部分。孑遗物种裸果木(Gymnocarpos przewalskii Maxim.)是1997年国家林业局进行全国重点保护野生植物资源调查时确定的国家一级重点保护植物,中亚特有濒危种,古地中海残遗种。本文通过野外调查和国内外公开发表的学位论文、期刊论文和会议论文等有关裸果木的论文以及国内公开的标本馆获取裸果木在新疆的实际分布点数据,对已获取的分布点数据进行筛选,共有样点数据97个。在ARCGIS支持下,分析了样点数据空间分布特征,厘清了孑遗物种裸果木的分布现状,为此后的模型模拟奠定了基础。利用MAXENT和GARP两种生态位模型,选择19个生物气候变量数据预测濒危物种裸果木在新疆潜在分布范围,并分析其各个环境变量对裸果木分布格局的贡献值。选出最优模型,预测其人类活动干扰对裸果木的分布影响,在RCP4.5未来气候模式下,预测了2050(2041-2060年),2070(2061-2080年)裸果木的潜在分布格局和分布面积,与当前气候条件下的分布面积和环境变量做对比分析,检验其模型的准确性。结果表明:1.裸果木在新疆的主要分布区位于天山南麓以南的广大洪积扇和冲积平原戈壁上连续分布区;东部天山哈密地区、天山北部奇台、木垒和阿尔金山北麓戈壁一带为裸果木的三个间断分布区。具体天然分布区位于昌吉州的奇台县、天山东部的哈密市以北以及巴里坤南部、伊吾县、位于天山以南的鄯善县、托克逊县、和硕县、库尔勒市、轮台县、库车县、拜城县、温宿县、阿克陶县、乌什县、乌恰县、疏勒县、疏附县和若羌等县市。2.在当前气候条件下,运用MAXENT模型计算裸果木潜在适生区总面积为43845km~2,其中潜在优适生区和潜在中适生区面积总和为20659km~2,GARP模型预测出的裸果木潜在适生区总面积为444079km~2,由于GARP模型预测的优和中适生区域包含了新疆北疆一带地区,且分布区面积区域与裸果木在新疆的实际分布区域差异明显,同时,MAXENT模型训练集和测试集AUC值分别为0.979、0.969、0.981、0.985、0.985、0.982、0.984、0.978均接近于1,说明预测效果好,因此,后期模拟计算时选择了MAXENT模型。3.运用MAXENT模型选择19个生物气候变量叠加人类活动干扰变量计算出裸果木潜在优和中适生区面积为19824km~2,比当前的潜在分布区面积减少了835km~2,说明了人类活动可使裸果木种群分布面积减少。4.在RCP4.5未来气候模式下,预测2041-2060年裸果木适生区总面积为40816km~2,比当前的潜在布区面积减少了3029km~2,2061-2080年适生区总面积为38476km~2,比当前的潜在分布区面积减少了5369km~2,裸果木分布区面积变化表明RCP4.5未来气候模式下裸果木分布范围和种群密度将减少。5.通过变量相关性分析,影响裸果木潜在分布的主要变量为降水量季节性变化、最热季降水量、年降水量、温度季节性变动系数等为主导环境变量。平均日较差、湿季平均温度、以及极端最高温、年平均气温等环境变量也对裸果木分布影响较大,其中降雨量和温度的变化对裸果木潜在分布的影响最为明显。裸果木的研究对我国西北地区荒漠的产生和发展、研究西北地区旱生植物区系成分的起源,以及气候的变化有着很高的的科学价值,因此通过本文提出主要的保护措施包括:裸果木分布较密集的地区建立自然保护区以及自然保护站,已有的自然保护区和保护站加大看管力度和保护力度,尽最大可能减少人为活动对保护区的影响,重视裸果木的引种和栽培,加强宣传教育和加大法律力度,完善法律体系。

As the main biological germplasm resources in the Gobi and desert areas,desert plants are an important part of the desert ecosystem.Gymnocarpos przewalskii Maxim.is a national first-class key protected plant identified by the State Forestry Administration in 1997 when the National Key Protected Wild Plant Resources Survey was conducted.Central Asia is endangered species and ancient Mediterranean remnants.This paper obtains the actual distribution point data of naked fruit trees in Xinjiang through field surveys and published papers on dissertation,journal articles and conference papers,as well as domestically published specimens.Screening,a total of 97 sample data.With the support of ARCGIS,the spatial distribution characteristics of the sample data were analyzed,and the distribution status of the naked fruit trees of the relict species was clarified,which laid the foundation for the model simulation.Using the two niche models of MAXENT and GARP,19bioclimatic variables were selected to predict the potential distribution of the endangered species naked fruit in Xinjiang,and the contribution of each environmental variable to the distribution pattern of naked fruit trees was analyzed.The optimal model was selected to predict the distribution of human activity disturbance on the distribution of naked fruit trees.Under the future climate model of RCP4.5,the potential distribution pattern of bare fruit trees in 2050(2041-2060)and2070(2061-2080)was predicted.The distribution area is compared with the distribution area and environmental variables under current climatic conditions,and the accuracy of the model is tested.According to the research results,the corresponding protection strategies are proposed.The results show:1.The main distribution area of naked fruit trees in Xinjiang is located in the continuous distribution area of the vast alluvial fan and the alluvial plain on the Gobi south of the Tianshan Mountains.The Hami area in the eastern Tianshan Mountains,the Qitai,Mulei in the northern Tianshan Mountains and the Gobi area in the northern part of the Altun Mountains are bare fruit trees.Three discontinuous distribution areas.The specific natural distribution area is located in Qitai County of Changji Prefecture,north of Hami City in the eastern Tianshan Mountains,and south of Balikun,Yiwu County,Shanshan County,Toksun County,Heshuo County,and Korla City.Counties such as Luntai County,Kuche County,Baicheng County,Wensu County,Akto County,Wushi County,Wuqi County,Shule County,Shufu County and Ruoqiang County.2.Under the current climatic conditions,the MAXENT model was used to calculate the total area of the potential suitable area of bare fruit trees was 43845 km~2,and the total area of potential suitable areas and potential medium-sized areas was20659 km~2.The GARP model predicted the potential area of bare fruit trees.The area is 444,079 km~2.The superior and medium-adapted areas predicted by the GARP model include the area of northern Xinjiang,and the area of the distribution area is significantly different from the actual distribution area of the naked fruit in Xinjiang.At the same time,the MAXENT model training set and test set AUC The values are0.979,0.969,0.981,0.985,0.985,0.982,0.984,and 0.978,respectively,which are close to 1,indicating that the prediction effect is good.Therefore,the MAXENT model was selected for the later simulation calculations.3.Using the MAXENT model to select 19 bioclimatic variables and superimposed human activity disturbance variables,the potential area of the naked fruit trees was calculated to be 19,824 km~2,which was 835 km~2 less than the current potential distribution area,indicating that human activities can distribute the population of the naked fruit trees.The area is reduced.4.Under the future climate model of RCP4.5,the total area of the bare fruit suitable area in the period of 2041-2060 is predicted to be 40,816 km~2,which is 3,029km~2 less than the current potential area,and the total area of the suitable area in the period of 2061-2080 is 38,476 km~2,which is more than the current The potential distribution area decreased by 5369km~2,and the change of the area of the bare fruit trees indicated that the distribution range and population density of the naked fruit trees in the future climate model of RCP4.5 would be reduced.5.Through the correlation analysis of variables,the main variables affecting the potential distribution of bare fruit trees are seasonal changes in precipitation,precipitation in the hottest season,annual precipitation,and seasonal variation coefficient of temperature as dominant environmental variables.The average daily poor,wet season average temperature,and extreme high temperature,annual average temperature and other environmental variables also have a greater impact on the distribution of bare fruit,and the change of rainfall and temperature has the most obvious impact on the potential distribution of naked fruit.The study of naked fruit trees has a high scientific value for the generation and development of deserts in northwestern China,the origin of the components of the cultivar in the northwestern region,and the change of climate.Therefore,the main protective measures proposed by this paper include:naked fruit trees The nature reserves and nature conservation stations will be established in densely populated areas.The existing nature reserves and protection stations will increase the intensity of supervision and protection,minimize the impact of human activities on the protected areas,and attach importance to the introduction and cultivation of naked fruit trees.Strengthen publicity and education,increase law and improve the legal system.

裸果木; MAXENT模型; GARP模型; 人类活动; 气候变化;

Gymnocarpos przewalskii Maxim; Maximum Entropy(MAXENT); Genetic Algorithm for Rule-set Prediction(GARP); human activity; climate change;

努尔巴依·阿布都沙力克; 师庆东;

Q948

127642906K