With increasing globalization, trade, and human movement, the rate of alien species introduction has increased all around the globe. In addition, climate change is thought to exacerbate the situation by allowing range expansion of invasive species into new areas. Predicting the distribution of invasive species under conditions of climate change is important for identifying susceptible areas of invasion and developing strategies for limiting their expansion. We used Maxent modeling to predict the distribution of one of the world's most aggressive invasive weeds, Ageratina adenophora (Sprengel) R. King and H. Robinson, in the Chitwan–Annapurna Landscape (CHAL) of Nepal under current conditions and 3 future climate change trajectories based on 3 representative concentration pathways (RCPs 2.6, 4.5, and 8.5) in 2 different time periods (2050 and 2070) using species occurrence data, and bioclimatic and topographic variables. Minimum temperature in the coldest month was the most important variable affecting the distribution of A. adenophora. About 38% (12,215 km2) of the CHAL area is climatically suitable for A. adenophora, with the Middle Mountain physiographic region being the most suitable one. A predicted increase in current suitable areas ranges from 1 to 2% under future climate scenarios (RCP 2.6 and RCP 8.5). All protected areas and 3 physiographic regions (Siwaliks, High Mountain, High Himalaya) are likely to gain climatically suitable areas in future climate scenarios. The upper elevational distribution limit of the weed is expected to expand by 31–48 m in future climate scenarios, suggesting that the weed will colonize additional areas at higher elevations in the future. In conclusion, our results showed that a vast area of CHAL is climatically suitable for A. adenophora. Expected further range expansion and upslope migration in the future make it essential to initiate effective management measures to prevent further negative impacts of this invasive plant.

中文翻译：

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预测尼泊尔奇旺–安那普尔纳景观中入侵杂草Ageratina adenophora的当前和未来分布

随着全球化，贸易和人类运动的增加，全球引进外来物种的比率也在增加。此外，气候变化被认为通过允许将入侵物种的范围扩大到新区域而加剧了这种情况。预测气候变化条件下的入侵物种的分布对于确定入侵的易感区域和制定限制其扩展的策略非常重要。我们使用Maxent建模来预测在当前条件和3个未来气候变化的情况下，尼泊尔奇旺-安纳布尔纳峰景观（CHAL）上世界上最具侵略性的入侵杂草之一-紫茎泽兰（Sprengel）R. King和H. Robinson的分布基于3种代表性浓度途径的轨迹（RCP 2.6、4.5和8。5）使用物种发生数据以及生物气候和地形变量在2个不同的时间段（2050和2070）中。最冷月份的最低温度是影响紫茎泽兰分布的最重要变量。CHAL地区约有38％（12215平方公里）在气候上适合紫茎泽兰，其中中山地貌是最合适的地区。在未来的气候情景下（RCP 2.6和RCP 8.5），当前适用区域的预计增长范围为1-2％。在未来的气候情景中，所有保护区和3个自然地理区域（Siwaliks，高山，喜马拉雅山）都可能​​获得适合气候的区域。在未来的气候情景中，杂草的海拔高度分布上限预计会扩大31–48 m，这表明该杂草将来会在更高海拔的地方定居。总之，我们的结果表明，CHAL的大面积气候适合紫茎泽兰。预期未来范围会进一步扩大和向上迁移，因此必须采取有效的管理措施来防止这种入侵植物的进一步负面影响。