气候变化背景下入侵植物曼陀罗在西藏的潜在风险区预测

生物安全与外来物种入侵是国门生物安全的重大生态学问题,生物入侵造成了巨大的经济损失与生物多样性快速丧失,还影响着人类的身体健康。西藏是我国重要的生态安全屏障,生态类型复杂且丰富多样,明确西藏区域尺度上外来入侵植物的潜在分布格局及其对气候变化的响应对入侵植物的预防和控制具有重要意义。为了探究入侵植物曼陀罗(Datura stramonium L.)对西藏生态安全的影响风险,基于野外实地调查数据,采用最大熵(Maxent) 模型,应用R语言和SPSS软件对模型参数和数据进行优化筛选,探讨影响其地理分布的主要环境因子,并模拟预测了当代及2种气候变化情景(RCP 45、RCP 85)下2050年和2070年, 其在西藏的潜在入侵风险区分布情况。结果表明:下层土壤酸碱度、年平均气温、最暖月最高温度与土壤有效含水量是影响曼陀罗分布的主导环境因子,海拔和人类活动影响强度也有重要作用;朗县、加查县、乃东区、城关区、八宿县、贡嘎县、巴宜区、波密县、察隅县、芒康县等地为入侵高风险地区;两种气候背景下曼陀罗的各级风险区面积和总风险区面积均呈持续增加的变化趋势,且在最高碳排放情景(RCP 85情景)下响应更为敏感;主要沿着低海拔河谷区域东南向西北方向入侵扩散的趋势,分布中心由当前的墨脱县域向工布江达县域转移。综合来说,曼陀罗在西藏分布受土壤环境、温度和降水影响较大,气候变化和人类活动影响强度将使其向西藏西部、北部扩散。研究结果可为西藏地区综合防控曼陀罗的入侵危害与动态监测提供生态学基础理论依据。

Prediction of potential risk area of the invasive plant Datura stramonium L. in Tibet under the background of climate change

Biosecurity and invasive alien species were major ecological issues of biosecurity at the national gate. Biological invasions has caused huge economic losses and rapid loss of biodiversity, and also affected human health. Tibet is an important ecological security barrier in China with complex and rich ecological types. It is of great significance to clarify the potential distribution pattern of invasive alien plants and their responses to climate change on a regional scale in Tibet for the prevention and control of invasive plants. In order to investigate the impact risk of the invasive plant Datura stramonium L. on the ecological security of Tibet, we used the Maxent model based on field survey data, applied R language and SPSS software to optimize the model parameters and data screening, explored the main environmental factors affecting its geographical distribution, and simulated and predicted its distribution in Tibet under contemporary and two climate change scenarios (RCP 45 and RCP 85) in 2050s and 2070s. We also simulated and predicted the distribution of potential invasion risk areas in Tibet under contemporary and two climate change scenarios (RCP 45 and RCP 85) in 2050s and 2070s. The results showed that: soil pH of subsoil, annual average temperature, the maximum temperature of the warmest month and available soil water content were the dominant environmental factors affecting the distribution of Datura stramonium L., and elevation and intensity of human activities also played an important role; Lang County, Jiacha County, Naidong County, Chengguan County, Basu County, Gongga County, Bayi County, Bomi County, Chayu County, and Mankang County would be the high risk areas for D. stramonium L. invasion based on field survey and model prediction; The area of risk areas at the respective levels and in the total risk area of D. stramonium L. showed trends of a continuous increase under two climatic backgrounds, and the response was more sensitive under the RCP 85 scenario (the highest carbon emission scenario); The trend of invasion and dispersal was mainly along the low elevation river valley area from southeast to northwest, and the distribution center would move from the current Medog County area to GongbuJiangda County area. To sum up, the distribution of D. stramonium L. in Tibet was greatly affected by soil environment, temperature and precipitation, and climate change and intensity of human activities will cause them to spread to western and northern Tibet. The results of the study can provide an ecological basic theoretical basis for the comprehensive prevention and control of the invasion hazard and dynamic monitoring of D. stramonium L. in Tibet.