Implications of Climatic Warming for Conservation of Native Trees and Shrubs in Florida

Abstract

Abstract: Ecological process models and empirical envelope models have been used to relate climatic‐change predictions to effects on plant species and vegetation. Climatic‐envelope models are useful for simultaneous investigation of many plant species whose range‐limiting mechanisms are poorly known. They are most effectively applied in regions with strong temperature and moisture gradients and low relief. Their required databases are often relatively easy to obtain. We provide an example involving the effect of six annual warming scenarios, ranging from +1° C to +2° C and from +10% to −20% annual precipitation (some have greater warming in winter than in summer), on 117 native woody species in Florida (U.S.A.). Tree species at their southern range boundaries in several parts of Florida are likely to be negatively affected by as little as 1° C warming if it is greater in winter than in summer or is accompanied by a 20% decrease in annual precipitation. Potential species responses to an identical type of 1° C warming may be different for some conservation areas in the same region of Florida. Potentially extensive disruption of some major woody ecosystems is predicted under certain types of 1° C annual warming and under all types of 2° C annual warming that were investigated. Additional consideration of nonclimatic factors suggests that many potential effects on species and ecosystems are not underestimates of actual effects over a 100‐year period of warming. We recommend monitoring for decreased fertility and viability of ecologically important, temperate woody species near their southern range limits in Florida. Early detection of such changes in fitness might then provide time for mitigations designed to alleviate more serious subsequent effects on biodiversity. Control of invasive, non‐native plant species and prevention of their additional introduction, human‐assisted translocation of native subtropical plant species into previously temperate parts of Florida, and restoration of more natural hydrological regimes are examples of potentially useful mitigations if climatic warming continues.