Developing pilot ecological indicator framework for detecting climate refugia, instability, and extinction debt using...

Area of Science:

• Ecology
• Climate Change Biology
• Conservation Science

Background:

• Mountain forest biodiversity is threatened by climate change, with conventional metrics inadequately assessing long-term ecological risks.
• Epiphytic orchids serve as sensitive indicators for climate-driven ecological shifts in montane ecosystems.

Purpose of the Study:

• To model current and future distributions of 10 epiphytic orchid species in the Northern Western Ghats, India.
• To develop and integrate a spatially explicit conservation framework using four ecological indicators to assess climate-resilient conservation needs.

Main Methods:

• Ensemble species distribution models (SDMs) were employed to predict orchid distributions under RCP2.6 and RCP8.5 climate scenarios for 2050 and 2070.
• A conservation framework integrating Priority Index (PI), Ecological Sensitivity Zoning (ESZ), Habitat Stability Index (HSI), and Extinction Debt (ED) was developed.
• Precipitation of the warmest quarter and climatic seasonality were identified as key drivers influencing species distribution.

Main Results:

• Suitable orchid habitats showed relative stability under low emissions (RCP2.6) but significant contraction and shifts under high emissions (RCP8.5).
• The developed framework identified climate refugia (PI, ESZ), indicated limited long-term persistence of biodiversity hotspots (HSI), and revealed potential future biodiversity losses (ED).

Conclusions:

• Integrating multiple ecological indicators provides a robust approach for climate-resilient conservation planning in mountain ecosystems.
• The study underscores the vulnerability of mountain orchid biodiversity to climate change and the necessity of proactive conservation strategies.