Terrain-Driven Water Accumulation Amplifies Propagule Pressure to Facilitate Ambrosia trifidaInvasion in Arid Grasslands: A Non-Climatic Similarity Perspective

Invasive alien plants pose significant threats to global ecosystems and economies. Understanding the drivers of their successful spread and colonization is critical for predicting and managing invasion events. Ambrosia trifida, native to humid regions, has rapidly invaded the arid hilly grasslands of the Yili Valley in China in recent years, challenging traditional climate niche theories. This study first use global-scale data to compare the climatic niches of the native range, global invaded regions, and the Yili Valley. It was found that the Yili Valley is characterized by a typical arid climate (aridity index