Parthenium weed (Parthenium hysterophorus L.) is an invasive alien plant species that is spreading rapidly all over the world. With globalization and climate change, it will continue to spread, posing threats to agriculture, biodiversity and the environment. To determine its invasion and impacts in Bhutan, an investigation was undertaken in West-Central Bhutan using a questionnaire survey, complemented by MaxEnt modelling. Most farmers (19–30%) recall having seen parthenium for the last 11–15 years, or more. Infestations of parthenium differed significantly (P < 0.05) across three districts for dryland, orchards, fallow land and pastures, but not in rice fields and on roadsides. The most intensely invaded land types were fallow land, pastures, and roadsides, with farmers perceiving it as ‘somewhat common’(score ~ 3) and ‘common’ (score ~ 4) weed. Farmers’ perceptions of the invasiveness of parthenium weed were high at 77% (Wangdue), 80% (Punakha), and 88% (Tsirang), considering it as at least ‘somewhat invasive’, or higher. Only 13–25% of respondents scored the weed as ‘highly invasive’. Parthenium invasion significantly (P < 0.01 to 0.001) escalated the cost of production, reduced fodder quality, supressed native species and caused allergies to the locals in the study districts. Further, MaxEnt modelling of parthenium distribution was undertaken, using the parthenium presence-only data and bioclimatic variables, under 2 CO₂ emission scenarios of the Intergovernmental Panel on Climate Change (IPCC), i.e. Representative Concentration Pathways (RCP2.6 and 8.5). The projections showed discernible spatial changes in climate suitability over 2070, mostly in the mid- and high-altitude zones, indicating aggressive incursion into Bhutan’s important agro-ecological landscapes. The findings, highlight the urgent need to initiate parthenium management strategies for food production and natural resources.

爬山虎杂草（Parthenium hysterophorus L.）是一种外来入侵植物，在世界范围内迅速传播。随着全球化和气候变化，它将继续蔓延，对农业，生物多样性和环境构成威胁。为了确定其在不丹的入侵和影响，在不丹中西部地区进行了调查，使用问卷调查，并辅以MaxEnt模型。大多数农民（19–30％）记得在过去的11–15年或更长的时间内见过hen。单性hen的侵染差异很大（P <0.05）分布在三个地区的旱地，果园，休耕地和牧场，但不在稻田和路边。入侵最严重的土地类型是休耕地，牧场和路边，农民认为这是“有点普通”（分数〜3）和“普通”（分数〜4）杂草。农民对单性ium杂草入侵的认识很高，认为它至少是“某种程度的入侵”或更高，分别为77％（Wangdue），80％（Punakha）和88％（Tsirang）。只有13–25％的受访者将杂草评为“高度侵入性”。hen的入侵显着（P <0.01至0.001）导致生产成本上升，饲料质量下降，本地物种被抑制并对研究地区的当地居民造成过敏。此外，在政府间气候变化专门委员会（IPCC）的2种CO ₂排放情景下，即代表性浓度途径（RCP2.6和8.5）下，使用仅存在hen的数据和生物气候变量，对Max的分布进行了MaxEnt建模。这些预测显示，到2070年，气候适应性存在明显的空间变化，主要发生在中高海拔地区，表明对不丹重要农业生态景观的侵略性入侵。这些发现强调了迫切需要启动粮食生产和自然资源的单性生殖管理策略。