Niche shifts drive the global distribution of a widespread plant invader of rangelands

Abstract

Biological invasions are a key component of global change. Thousands of exotic plant species are distributed worldwide, potentially disrupting ecosystem functioning. There is a particular need to investigate invasive species at high latitudes, especially in the Southern Hemisphere, where research is limited. We conducted a study to evaluate the niche shifts of Hieracium pilosella, a species native to Eurasia and invasive in high-latitude rangelands in North America, Oceania, and South America. We assessed niche conservatism across diferent regions using niche modeling techniques. Our fndings reveal niche shifts between native and invasive populations of H. pilosella. In all invaded ranges, there is both niche expansion into environments not occupied in the native range and unflling of habitats that belong to the native niche. The overlap of the native niche with the invasive niches varies between invaded regions but is generally lesser than expected by chance. The potential range of H. pilosella may increase considerably in some regions if it colonizes unflling habitats. Therefore, it is crucial to maintain ongoing observation and monitoring methods to control this troublesome species. Understanding spatial niche dynamics in problematic invasive species that invade high-latitude ecosystems ofers valuable insights for the global investigation and management of invasions. This is especially relevant in the context of climate change, where such invasions may expand toward higher latitudes soon.