Modeling the Spatial Distribution and Adaptive Conservation Strategies of Pentachlaena latifolia H. Perrier (Sarcolaenaceae) under Climate Change in the Ibity Massif Protected Harmonious Landscape

Abstract

Background: Pentachlaena latifolia H. Perrier (Sarcolaenaceae) is an endemic species of the Central Highlands of Madagascar, mainly found in the Tapia forests of the Ibity Massif. Its limited dispersal capacity makes it vulnerable to climate change. This study aims to model its future distribution to assess habitat dynamics and guide adaptive conservation. Materials and Methods: Occurrence data obtained from GBIF, Tropicos, the PBZT herbarium–COST 01, and field surveys were spatially filtered at a resolution of 1 km × 1 km and analyzed using the Biomod2 platform in R through an Ensemble Modelling approach (GLM, GAM, RF, MaxEnt, and GBM). Current and future projections (2041–2060) were generated using seven bioclimatic variables from WorldClim v2.1 under the SSP2-4.5 and SSP5-8.5 climate scenarios. Results: The model showed excellent predictive performance (AUC = ; TSS = ). Species distribution was mainly influenced by precipitation seasonality (BIO15: ) and precipitation of the driest month (BIO14: ). Projections indicate a shift in suitable habitats toward high-altitude ridges (800–1,000 m), accompanied by a net habitat loss of under the SSP2-4.5 scenario and under the SSP5-8.5 scenario. Only of the potential climatic refugia are currently covered by the Ibity Massif Protected Area, while the existing Management and Development Plan (PAG) does not explicitly incorporate climate change. Conclusion: Climate change represents a major threat to P. latifolia. Its conservation requires adaptive management based on the expansion of protected areas toward high-altitude climatic refugia, restoration of Tapia forests, strengthening of ecological connectivity, in situ and ex situ conservation, and dynamic revision of managements plans.