Responses to canopy loss and debris deposition in a tropical forest ecosystem: Synthesis from an experimental manipulation simulating effects of hurricane disturbance

Abstract

a b s t r a c tHurricanes, cyclones, or typhoons are intense and broad-scale disturbances that affect many island and coastal ecosystems throughout the world. We summarize the findings of the articles that compose this special issue of Forest Ecology and Management, which focuses on a manipulative experiment (the Canopy Trimming Experiment, CTE) that simulates two key aspects of hurricane effects in a wet tropical forest. Although previous studies of tropical and subtropical forests have documented changes resulting from hurricanes, it is not clear which of the two simultaneously occurring direct effects of hurricanes-canopy openness or debris deposition-most influence responses. In the Luquillo Experimental Forest (LEF) of Puerto Rico, a multi-disciplinary team of scientists used replicated factorial manipulations to determine the independent and interactive effects of canopy openness and debris deposition on structural and functional characteristics of the forest. The majority of responses were primarily driven by canopy openness rather than by debris deposition. Canopy openness resulted in significant increases in densities of and compositional changes in woody plants, ferns, and some litter arthropods, and significant decreases in coqui frog abundances, leaf decomposition, and litterfall. Debris deposition significantly increased tree basal area and microbial diversity on leaf litter, but these increases were relatively small and ephemeral. Several interactive effects of canopy openness and debris addition emerged, including those involving understory herbivory, canopy arthropod structure, terrestrial gastropod abundances and composition, and soil solution chemistry. Arguably, hurricanes are the most important natural disturbance that affect the LEF, and most characteristics that were measured in the CTE showed evidence of resistance or resilience. By identifying the causal factors affecting secondary successional trajectories of diverse taxa ranging from microbes to vertebrates, biogeochemical attributes, microclimatic characteristics, and measures of ecosystem processes following hurricane disturbance, we better understand tropical forest dynamics resulting from past hurricanes and are better able to predict mechanisms of change related to future hurricanes.Published by Elsevier B.V.

Responses of Soil Labile Organic Carbon to a Simulated Hurricane Disturbance in a Tropical Wet Forest

“…This study was conducted in the Canopy Trimming Experiment (CTE) plots, which are located in the Luquillo Experimental Forest, Puerto Rico [30]. This forest is a subtropical wet forest, according to the landscape life zone classification system of Holdridge, and is characterized as a tabonuco forest type [14].…”

Soil Biology Research across Latitude, Elevation and Disturbance Gradients: A Review of Forest Studies from Puerto Rico during the Past 25 Years

“…Given the persistence of both anthropogenic and non-anthropogenic disturbances in the tropics, it is important to study the diversity of its fauna and assess how they can affect ecosystem functioning. For example, recent research has focused on the effects of disturbance on arthropods and their connectivity to other biotic and abiotic factors in forested ecosystems that can have significant effects on detrital processes [14][15][16][17].…”

On the Shoulders of Giants: Continuing the Legacy of Large-Scale Ecosystem Manipulation Experiments in Puerto Rico

“…All trees with diameter at breast height of greater than 9.1 cm were tagged, measured, and identified to species. These plots have been re-measured at various points in time from 1947 to present, providing a baseline for understanding the growth and productivity of thousands of trees within the Luquillo Experimental Forest over a 75-year period [41][42][43][44][45][46][47], and a critical foundation against which experimental results have be compared [15,40,48,49].…”