Ephedra equisetina, the Nitraria species complex (N. sibirica, N. roborowskii and N. sphaerocarpa), and Rheum nanum are the main dietary plants of the Gobi Bear (Ursus arctos gobiensis), a subspecies of the brown bear, found in the Gobi desert of Mongolia. Their location and distribution range are closely related to the Gobi Bear survival. Analyzing the impact of climate change on the possible distribution of these species is essential for the future conservation and management of the Gobi Bear. In this study, we modeled the current and future distribution of the main dietary plants of the Gobi Bear based on one representative concentration pathway (RCP2.6) for the period from 2041 to 2060 (2050s) and 2061-2080 (2070s) using a maximum entropy (MaxEnt) species distribution model. Our results showed that the precipitation-associated variables had the strongest effect on the distributions of these species. Among these variables, the precipitation of the coldest quarter (Bio19) was the most important variable affecting the suitability of the habitats. Under the current climate conditions, the areas of the highly suitable (>0.6) habitat for E. equisetina, the Nitraria species complex, and R. nanum were 3,888.51, 23,727.78 and 13,816.88 km², respectively, accounting for 8%, 52% and 30% of the Great Gobi “A” Strictly Protected Area. In the year 2050s and 2070s, the highly suitable habitat areas for E. equisetina and R. nanum will continue to increase and eventually reach to 23% and 36%, respectively. The Nitraria species complex would first be reduced to 33% in the 2050s and then increase to 36% in the 2070s. With the climate warming, the highly suitable habitats of the Gobi Bear's main dietary plants would shift to the southeast. These results, together with previous studies about the Gobi Bear distribution can provide useful information and a reasonable reference for managers to put forward suggestions for better protection of the Gobi Bear.

Ephedra equisetina，Nitraria种复合体（N. sibirica，N。roborowskii和N. sphaerocarpa）和Rheum nanum是戈壁熊（Ursus arctos gobiensis）的主要饮食植物。）是棕熊的一个亚种，在蒙古的戈壁沙漠中发现。它们的位置和分布范围与戈壁熊的生存密切相关。分析气候变化对这些物种可能分布的影响，对于戈壁熊的未来保护和管理至关重要。在这项研究中，我们基于一个代表性的浓度途径（RCP2.6），对2041年至2060年（2050年代）和2061-2080（2070年代）期间的戈壁熊主要饮食植物的当前和未来分布进行了建模，最大熵（MaxEnt）物种分布模型。我们的结果表明，与降水相关的变量对这些物种的分布影响最大。在这些变量中，最冷的季度（Bio19）的降水是影响生境适宜性的最重要变量。在当前的气候条件下，高度适合（> 0.6）的栖息地E. equisetina，Nitraria物种群和R. nanum分别为3,888.51、23,727.78和13,816.88 km ²，分别占大戈壁“ A”严格保护区的8％，52％和30％。在21世纪50年代每年21世纪70年代，并为高度适宜的栖息地E.木贼麻黄和R. nanum将继续增加，并最终达到23％和36％，分别。在白刺物种复合体将首先在2050年代减少到33％，然后在2070年代增加到36％。随着气候变暖，戈壁熊主要饮食植物的高度适宜的生境将转移到东南部。这些结果，再加上以前对戈壁熊分布的研究，可以为管理者提出更好地保护戈壁熊的建议提供有用的信息和合理的参考。