Climate change may shift plague risk zones in China’s Northern Tianshan

Plague, caused by the bacterium Yersinia pestis, circulates silently in wild rodent populations, and its persistence depends on a delicate interplay between climate, landscape, and host–pathogen dynamics. In a new modeling study, researchers focused on the Northern Tianshan Natural Plague Focus in Xinjiang, China, where the gray marmot Marmota baibacina serves as a key reservoir host. By combining an optimized maximum entropy model with joint distribution copula functions, the team mapped how suitable habitats for the marmot and the bacterium, and the resulting plague transmission risk, could change under current and future climate scenarios.

The projections indicate that high-suitability habitats for both M. baibacina and Y. pestis within the focus are expected to undergo both contraction and expansion in the coming decades. Notably, the two organisms respond to different environmental drivers. The marmot’s distribution was primarily determined by temperature-related variables Bio6 and Bio7, together with precipitation seasonality (Bio15), whereas the bacterium’s suitability was predominantly shaped by Bio15 and elevation. This divergence in environmental controls helps explain why the two distributions may shift in different directions as the climate changes.

When the researchers integrated these habitat projections into an overall assessment of plague transmission risk, they found that the spatial footprint of high-risk areas is likely to move through distinct phases of stability, contraction, and expansion, depending on the climate scenario and time period considered. One of the most striking findings concerns the geographic center of gravity of risk: the centroid of high-risk regions may migrate from Wusu City to Nileke County, indicating that the location where epizootic activity could concentrate is projected to change under future conditions.

The authors conclude that under future climate scenarios, the distribution and transmission risk of plague in the Northern Tianshan focus may be strongly influenced by environmental factors, producing spatial changes that depend on both the emission scenario and the projection period. The western portion of the focus is anticipated to experience the most pronounced shifts and is projected to remain at elevated risk of epizootic plague. Because these results are model-based projections rather than observations of actual outbreaks, they should be interpreted as scenario-dependent estimates of where suitable conditions for the marmot host, the bacterium, and plague transmission may arise as the climate of this remote mountain ecosystem evolves.

Subject of Research: Integrating MaxEnt and copula models to assess plague-associated ecological suitability under climate change in Northern Tianshan, China

Article Title: Integrating MaxEnt and copula models to assess plague-associated ecological suitability under climate change in Northern Tianshan, China

Article References: Li, F., Zhao, G., Moming, A., Liu, X., Ma, P., Zhan, S., Wang, H., Chen, J., Tuerdali, W., Wang, Q., Luo, T., Wu, H., & Zhang, Y. (2026). Integrating MaxEnt and copula models to assess plague-associated ecological suitability under climate change in Northern Tianshan, China. PLOS Neglected Tropical Diseases, 20(10), e0014818. https://doi.org/10.1371/journal.pntd.0014818

Image Credits: AI Generated

DOI: 10.1371/journal.pntd.0014818

Keywords: Integrating, MaxEnt, copula, models, assess, plague-associated, ecological, suitability, under, climate, change, Northern