Climate-change habitat shifts for the vulnerable endemic oak species (Quercus arkansana Sarg.)

Quercus arkansana (Arkansas oak) is at risk of becoming endangered, as the total known population size is represented by a few isolated populations. The potential impact of climate change on this species in the near future is high, yet knowledge of its predicted effects is limited. Our study utilized the biomod2 R package to develop habitat suitability ensemble models based on bioclimatic and topographic environmental variables and the known locations of current distribution of Q. arkansana. We predicted suitable habitats across three climate change scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5) for 2050, 2070, and 2090. Our findings reveal that the current suitable habitat for Q. arkansana is approximately 127,881 km² across seven states (Texas, Arkansas, Alabama, Louisiana, Mississippi, Georgia, and Florida); approximately 9.5% is encompassed within state and federally managed protected areas. Our models predict that all current suitable habitats will disappear by 2050 due to climate change, resulting in a northward shift into new regions such as Tennessee and Kentucky. The large extent of suitable habitat outside protected areas suggests that a species-specific action plan incorporating protected areas and other areas may be crucial for its conservation. Moreover, protection of Q. arkansana habitat against climate change may require locally and regionally focused conservation policies, adaptive management strategies, and educational outreach among local people.