Ecological implications of hurricane disturbances: immediate responses, resiliency, and recovery

Abstract:

A current challenge is to understand what are the impacts of extreme climate events on ecosystem processes and functions. This presentation focuses on the ecological implications of a direct impact of major hurricane (Wilma, 2005) on a tropical forest, and a surge event created by a hurricane (Joaquin, 2016) on a temperate salt marsh. Hurricane disturbances create visible effects on tropical forests (e.g., uprooting of trees), but also influence plant physiology, ecosystem gross primary productivity (GPP), and decomposition rates of organic matter. Hurricane Wilma defoliated trees and decreased >15% of the long-term annual mean forest GPP, increased soil CO₂ efflux to an unprecedented rate of >3.9 kgC m^-1 y^-1, and trees were able to use old stored non-structural carbon (>10 years old) to produce new fine roots. Despite these immediate responses, tropical forests recovered within the first two years following hurricane events. Coastal salt marshes have less visible effects, and arguably they are more resilient to hurricane disturbances. However, these ecosystems are influenced by storm surge events that increase water salinity and raise water table depth influencing non-visible effects (e.g., ecosystem processes). The surge of hurricane Joaquin had an immediate influence (<1 month) on diel patterns of CO₂ and CH₄ production and fluxes in soils, creeks, and at the ecosystem scale, but had no influence on vegetation structure. Information on the influence of extreme climate events in natural ecosystems is limited (as these events are rare), but there is a pressing need to identify how these events change ecosystem processes to propose new hypotheses and improve our predictive capabilities.