Canopy Trimming Experiment (CTE)

The Canopy Trimming Experiment (CTE) was initiated in 2002 in the El Verde Research Area. The first trimming treatments were designed to separate canopy opening and debris deposition, the two principal effects of hurricane disturbance to our forests (Zimmerman et al. 1994, Shiels & González 2014). This long-term experiment has allowed us to separate the role of microclimate, detrital inputs, and different functional groups of decomposers on detrital processing and ecosystem resilience after canopy disturbance (Shiels et al. 2015). Through once-a-decade repeated canopy manipulations, the CTE will also allow us to assess the effects of a projected increased frequency of intense hurricanes (Knutson et al. 2010) on forest composition, soil C storage, nutrient dynamics (Sanford et al. 1991, Gutiérrez del Arroyo & Silver 2018), population dynamics, and trophic structure (see Hypotheses 1 and 2). Each treatment covers a 30 x 30 m area with an inner 20 x 20 m measurement plot. The first experiment consisted of four treatments in each of three blocks. and included: 1) canopy trimmed, with debris addition, changing microclimate, forest floor mass, and nutrient content, 2) canopy trimmed, without debris addition, 3) canopy not trimmed, but debris added, changing forest floor mass and nutrient content, 4) untreated control. To study an increased frequency of intense hurricanes, treatments 1 and 4 (hurricane and control) will be repeated every 10 years for at least 50 years duration. The first of the repeated disturbances, the second canopy trimming treatment, took place in late 2014; measurements are continuing (Table 1). In LUQ VI we plan to repeat these treatments in 2024.