Evaluating urban tree population fitness for a changing climate: Using climatic moisture index

Abstract

Species Distribution Models (SDMs) are essential tools for understanding how species respond to climatic and environmental changes. In this study, we examine the relationship between Climatic Moisture Index (CMI) and leaf water potential (Ψ_P0) across a variety of tree species to explore how climatic moisture conditions influence tree physiology, particularly in terms of drought tolerance. Using linear regression analysis, we found a statistically significant relationship between CMI and Ψ_P0, with the direction of the slope indicating how species respond to changes in moisture availability. Species with a positive relationship between CMI and Ψ_P0 exhibited greater tolerance to fluctuating moisture conditions, while those with a negative relationship showed a higher susceptibility to drought stress. The findings underscore the importance of incorporating climatic factors into conservation and management strategies, particularly for species at risk of water stress under changing climate conditions. This research contributes to a broader understanding of tree physiology, with implications for conservation, restoration, and urban tree selection efforts in the face of global climate change.