Community and Population Characteristics and Future Potential Habitats Under Climate Change of Juniperus Species in Yunnan, Southwestern China

Juniperus, a genus shaped by long-term climatic and geological processes, thrives in Yunnan but its community structure and future habitat dynamics remain poorly understood. We investigated Juniperus community composition, phylogenetic diversity, population structure, and projected suitable future habitats using MaxEnt modeling. Seven distinct community types were identified, all dominated by Juniperus species. They were characterized by low species richness, strong dominance patterns, and uneven species distribution. Most communities displayed a multi-layered vertical structure, except Type 6. Phylogenetic analyses revealed overdispersion (NRI < 0) in most communities, indicating habitat filtering as the primary assembly process, while Type 2 (NTI > 0) comprised more closely related species, potentially due to external disturbance. Population structures varied: J. pingii var. wilsonii exhibited an inverse J-shaped DBH distribution, J. formosana and J. squamata had unimodal patterns, and other species showed multimodal distributions. Climate projections forecast a 4.5–41.9% loss of suitable habitat, with current nature reserves covering only 13.6–35.1% of stable refugia, highlighting the need for targeted conservation. These findings provide an essential basis for the conservation, afforestation, and restoration of Juniperus-dominated ecosystems in Yunnan.