Globally consistent impact of tropical cyclones on the structure of tropical and subtropical forests

Abstract

Tropical cyclones (TCs) are large‐scale disturbances that regularly impact tropical forests. Although long‐term impacts of TCs on forest structure have been proposed, a global test of the relationship between forest structure and TC frequency and intensity is lacking. We test on a pantropical scale whether TCs shape the structure of tropical and subtropical forests in the long term. We compiled forest structural features (stem density, basal area, mean canopy height and maximum tree size) for plants ≥10 cm in diameter at breast height from published forest inventory data (438 plots ≥0.1 ha, pooled into 250 1 × 1‐degree grid cells) located in dry and humid forests. We computed maps of cyclone frequency and energy released by cyclones per unit area (power dissipation index, PDI) using a high‐resolution historical database of TCs trajectories and intensities. We then tested the relationship between PDI and forest structural features using multivariate linear models, controlling for climate (mean annual temperature and water availability) and human disturbance (human foot print). Forests subject to frequent cyclones (at least one TCs per decade) and high PDI exhibited higher stem density and basal area, and lower canopy heights. However, the relationships between PDI and basal area or canopy height were partially masked by lower water availability and higher human foot print in tropical dry forests. Synthesis. Our results provide the first evidence that tropical cyclones have a long‐term impact on the structure of tropical and subtropical forests in a globally consistent way. The strong relationship between power dissipation index and stem density suggests that frequent and intense tropical cyclones reduce canopy cover through defoliation and tree mortality, encouraging higher regeneration and turnover of biomass. The projected increase in intensity and poleward extension of tropical cyclones due to anthropogenic climate change may therefore have important and lasting impacts on the structure and dynamics of forests in the future.

Functional diversity improves tropical forest resilience: Insights from a long‐term virtual experiment

“…The main type of disturbance across the tropics is forest logging, encompassing selective timber harvesting in old‐growth forests and wood fuel harvesting mainly in secondary forests (Pearson, Brown, Murray, & Sidman, ). In addition to direct human impacts, global change is modifying regional climates with, for instance, an increase in the frequency and intensity of drought events and associated fires (Davidson et al, ) and of convective storms (Negrón‐Juárez et al, ), both resulting in increased tree mortality rates and forest biomass loss (Ibanez et al, ; Phillips et al, ).…”

Effects of a tropical cyclone on salt marsh insect communities and post‐cyclone reassembly processes

“…High winds and storm surges occur annually within three large cyclone belts in most subtropical and warm‐temperate regions of the world (Emanuel ). These storms directly damage and influence survival of individuals within populations, as well as initiate post‐cyclone responses, often in altered environments (Whitmore , , Batista and Platt , Turton and Stork , Lin et al 2012, Turton , Chi et al , Ibanez et al ). As a result, tropical cyclones impact local species distributions, species interactions, community structure, and ecosystem functions (Vandermeer et al , Schoener et al , Turner et al , Spiller and Schoener , Willig et al , Sanchez‐Galvan et al , Platt et al ).…”

“…As a result, tropical cyclones impact local species distributions, species interactions, community structure, and ecosystem functions (Vandermeer et al , Schoener et al , Turner et al , Spiller and Schoener , Willig et al , Sanchez‐Galvan et al , Platt et al ). Further, recurrent tropical cyclones produce consistent compositional and structural patterns regionally and worldwide, despite large taxonomic and evolutionary differences among organisms in the different regions experiencing these recurrent disturbances (Quigley and Platt , Keppel et al , Ibanez et al ).…”

“…Such concepts include resistance and resilience of populations to disturbance (sensu Bellingham et al , Batista and Platt ) that results in direct regeneration of community composition and structure (sensu Boucher , Boucher et al , , Yih et al , Vandermeer et al , , Dietze and Clark , Lin et al , Imbert ). The direct regeneration hypothesis, that communities are likely to return to pre‐disturbance conditions following disruption, emerged primarily from empirical study of sedentary organisms in forested ecosystems (Lugo , Keppel et al , Xi , Imbert , Ibanez et al ) and marine coral reef and intertidal systems (Harmelin‐Vivien , Connell , Lugo et al , Greening et al , Gouezo et al , Mathews and Maccarone , Olin et al ). Development of concepts related to effects of tropical cyclones on natural systems thus should benefit from studies of different types of systems.…”

Forests affected by frequent and intense typhoons challenge the intermediate disturbance hypothesis

“…Tropical cyclones are among the most-common natural disturbances globally, and their frequency and intensity are projected to increase in many parts of the world in the future (Chand, Tory, Ye, & Walsh, 2017;Emanuel, 2005Emanuel, , 2013Ibanez et al, 2019). In fact, tropical cyclone disturbance was used many times to illustrate the IDH by Connell (1978).…”