Understanding hurricane resistance and resilience in tropical dry forest trees: A functional traits approach

Abstract

Understanding hurricane resistance and resilience in tree species is a challenge to the management and conservation of coastal tropical forests. Tree responses to hurricanes partly depend on species attributes related to architecture and resource use strategy; however, few studies have used multiple traits to identify the role of functional trade-offs in tree resistance and resilience. In this study, we apply a functional traits approach to explore how characteristics involved in tree shape, size and function influence the type and severity of damage by hurricane winds, and examine the potential for recovery by re-sprouting. We tested the hypothesis that traits involved in the fast-slow trade-off mediate tree responses to hurricanes. Eighteen months after the passing of a category 2 hurricane, we assessed the damage types found in 993 trees of dbh > 10 cm, from 36 dominant tree species in a tropical dry forest on the Mexican Pacific coast that was impacted by the event, and measured five functional traits related to species size, architecture and resource acquisition strategy. In addition, the sectional area recovered by re-sprouting in main tree trunks or branches was measured in 16 species. The results indicated that several traits could serve as good indicators of resistance and resilience. Maximum height, wood density and specific leaf area correlated positively with severe damage (together accounting for up to 47% of the variance in uprooting). In turn, re-sprouting recovery was positively associated with maximum height and specific leaf area but negatively with wood density and slenderness (together informing ca. 50% of the variance). We found evidence that the fast-slow continuum of resource use strategies can mediate the capacity of trees to resist and recover following hurricane winds; however, contrary to expectation, the consequences of the fast-slow syndrome for the response to hurricanes seem to vary with the axis of plant strategies considered. Our results challenge the notion that dense-wooded trees of the tropical dry forest should resist hurricanes better, and suggest that these climatic events may actually favor light-wooded, wide-stemmed trees.