Analysis of Spatial Suitable Habitats of Four Subspecies of <i>Hippophae rhamnoides</i> in China Based on the MaxEnt Model

<i>Hippophae rhamnoides</i> L. is an ecologically and medicinally significant species widely distributed across Eurasia, the suitable habitat of <i>H. rhamnoides</i> subsp. <i>sinensis</i> (is hereinafter referred to as <i>sinensis</i>) is concentrated in Northwest and Southwest China (approximately 34–40° N, 100–115° E). <i>H. rhamnoides</i> subsp. <i>yunnanensis</i> (hereinafter referred to as <i>yunnanensis</i>) is mainly distributed in the Hengduan Mountains and surrounding areas (approximately 25–30° N, 98–103° E). <i>H. rhamnoides</i> subsp. <i>mongolica</i> (hereinafter referred to as <i>mongolica</i>) is native to Central Asia to Siberia and is mainly distributed in Northern Xinjiang and Western Inner Mongolia in China (approximately 40–50° N, 100–120° E). <i>H. rhamnoides</i> subsp. <i>turkestanica</i> (hereinafter referred to as <i>turkestanica</i>) is mainly distributed in Western Xinjiang (approximately 40–45° N, 70–85° E). Climate change poses a considerable challenge, affecting its distribution and leading to shifts in its habitat ranges. This study applies the MaxEnt model to assess climate-driven distribution patterns of <i>Hippophae</i> species in China, and predicts current and future suitable habitats under climate change scenarios. This study employs the MaxEnt model and ArcGIS to simulate the potential distribution of four subspecies of <i>H. rhamnoides</i> during the current period and future projections under scenarios SSP1–2.6 and SSP5–8.5. The analysis reveals that the distributions of <i>sinensis</i>, <i>mongolica</i>, <i>yunnanensis</i>, and <i>turkestanica</i> are influenced primarily by climate variables such as temperature and precipitation, while <i>yunnanensis</i> is predominantly restricted by altitude. Future projections indicate that under the extreme climate of SSP5–8.5, centroid migration will be disrupted; specifically, <i>sinensis</i> is expected to migrate northeast or oscillate, <i>mongolica</i> will expand southwest but be limited by desert steppe zones, and <i>turkestanica</i> may face risks associated with groundwater depletion. This study advocates for integrating climate, ecological, and genetic data into conservation planning, with an emphasis on groundwater restoration and exploring genetic resources for stress resilience. The insights offered here contribute significantly to understanding climate adaptation mechanisms in arid and mountainous ecosystems and guide biodiversity conservation efforts.