Assessing Potential Habitat Suitability of the Endangered Endo-Holoparasitic Sapria himalayana and Its Multiple Hosts in China Under Global Warming

Global warming severely threatens parasitic plants worldwide. However, little is known about how a parasite with multiple hosts responds to climate change in its distribution. <i>Sapria himalayana</i> is an endangered endo-holoparasite, obligately parasitizing <i>Tetrastigma</i> species. We employed MaxEnt to predict suitable habitats for <i>S. himalayana</i> and its five hosts, and determined key environmental factors. Then, we calculated niche overlaps for the five parasite-host pairs. Currently, it covers a suitable area of 1.35 × 10⁴ km², accounting for 0.14% of China's total territory. Temperature-related variables were identified as the key factors shaping potential distribution for this parasite and three hosts (i.e., <i>T. planicaule</i>, <i>T. obovatum</i>, and <i>T. cruciatum</i>), while precipitation-related ones were identified for the other hosts (i.e., <i>T. obtectum</i> and <i>T. serrulatum</i>). Collectively, the five pairs presented low niche overlaps under current and future scenarios. While <i>S. himalayana</i> will increase by 37.78% in future suitable habitat, the two host categories show contrasting trends in potential habitat shifts. Divergent climatic sensitivities across host species, along with parasite-host suitability mismatches, could shape the survival and distribution of <i>S. himalayana</i>. Consequently, this research offers valuable insights for the conservation of <i>S. himalayana</i> in China, highlighting the necessity of safeguarding its distinct hosts under global warming.