Abstract
Climate change and biological invasions represent significant drivers of biodiversity loss, and changes in climate and land use can also synergistically influence the naturalization of alien species into new areas. Therefore, reporting the transition of alien plant species along the casual-naturalization-invasion continuum can be crucial to the early detection of alien species and their timely management with lower costs. Here, we report the distribution of the recently naturalized plant species Matricaria discoidea DC. (Pineapple-weed) in Ladakh, a remote region located in the Trans-Himalayan region of Ladakh. We provide a taxonomic description of M. discoidea and photo-illustrations of its distinctive characters for easy field identification. Based on the sampling of communities dominated by M. discoidea, we found it positively associated with plant species that habitat preferences similar to M. discoidea but negatively associated with several native plant species that occurred in the same community. Our findings suggest that this newly naturalized alien species can potentially spread throughout this trans-Himalayan region and may have ecological consequences, including the negative impact on native species diversity in the region.