Empirical data and model simulations of the effect of repeated hurricanes on soil carbon dynamics in a humid tropical forest

Increasing hurricane frequency and intensity with climate change is likely to affect soil organic carbon (C) stocks in tropical forests. We examined the cycling of C between soil pools and with depth at the Luquillo Experimental Forest in Puerto Rico in soils over a 30-year period that spanned repeated hurricanes. We used a non-linear matrix model of soil C pools and fluxes (“soilR”) and constrained the parameters with soil and litter survey data. Soil chemistry and stable and radiocarbon isotopes were measured from three soil depths across a topographic gradient in 1988 and 2018. Our results suggest that pulses and subsequent reduction of inputs caused by severe hurricanes in 1989, 1998, and two in 2017 led to faster mean transit times and younger mean ages of soil C in the particulate, occluded, and mineral-associated soil organic matter pools at 0–10 cm and 35–60 cm depths relative to a modeled control soil with constant inputs over the thirty years. Between 1988 and 2018, the occlud..., Site description
Soils were sampled from the Bisley Experimental Watershed of the LEF, Puerto Rico (18.3157 deg. N, 65.7487 deg W), a Long-Term Ecological Research and Critical Zone Observatory and Network site (https://luq.lter.network). The mean maximum daily temperature at Bisley was 27 ºC between 1993 and 2010 (Gonzales, 2020), with little seasonality. The mean annual precipitation at Bisley was 3883 (± 864 s.d.) mm y-1 from 1988 through 2014 (González, 2017; Murphy et al., 2017). Rainfall occurs all year, though January through April experience slightly less precipitation than other months (Heartsill-Scalley et al., 2007). The site is a humid tropical forest with a diverse tree community of approximately 170 species > 4 cm diameter at breast height (Weaver & Murphy, 1990), and dominated by tabonuco (Dacryodes excelsa Vahl). Elevation of Bisley spans from 261 m a.s.l. at the base to 450 m a.s.l. on the ridges (Scatena, 1989).
Soils in Bisley are derived from volcaniclastic se..., , # Empirical data and model simulations of the effect of repeated hurricanes on soil carbon dynamics in a humid tropical forest

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## Description of the Data and file structure

### All Bisley Data.csv

This is a CSV file containing empirical data from 1988 and 2018 sampling dates in the Bisley Watershed of Luquillo Experimental Forest.

* Year: sampling year
* Topography: One of four positions, either Ridge, Slope, Upland Valley or Riparian Valley
* Depth: Midpoint in cm of depth horizon (e.g. -5 indicates 0 - 10 cm)
* Top of horizon: (cm)
* Bottom of horizon: (cm)
* Fraction: Density fraction - HF (heavy fraction), OLF (occluded light fraction), or FLF (free light fraction)
* Sample: Full sample name including all descriptors
* d13C: stable isotope delta 13 C in per mile
* fraction modern: Fraction of modern carbon as measured by accelerator spectrometer radiocarbon data
* plus_minus: analytical standard error of fraction modern
* Del14C: Capital Delta 14C, or ...