We sampled soils from 216 profiles representing 24 sites in the El Yunque National Forest to determine amounts C, N and neutral-salt-extractable Ca++, Mg++ and K+. Following the classic paradigm, we assessed the influence of climate (modeled precipitation, modeled temperature and/or elevation as a surrogate variable for both), forest type (tabonuco, colorado, palm), parent material (quartz diorite, volcaniclastics), and topography (catena positions ridge, slope, valley and % slope) on the distribution of these nutrients.
Through a partnership with Jane Horwitz at the Penn Arts & Sciences Science Outreach Initiative and two teachers in the Radnor and Lower Merion school districts, activities for high school students studying mathematics and environmental science were developed for Honors and College Prep high school students.
This activity is presented here in the attached file.
Geophysical surveys conducted during the summer of 2014 followed on previous work that investigated the nature and spatial variability of ground penetrating radar (GPR) reflections in the Rio Icacos watershed (Figure 1a). GPR surveys using a variety of shielded (160 MHz) and unshielded (50, 100 and 200 MHz) antennas (Figure 1e) was combined with multi-frequency terrain conductivity measurements to upscale previous measurements.
GPR, ground penetrating radar, terrain conductivity, electrical resistivity imaging
A sample of data from three groundwater monitoring locations in the Icacos / Rio Blanco watershed are included here. Requests for a complete dataset will be considered, please email email@example.com with an explanation of what you would like to do with the data. A complete dataset will be released to the public at a later date.
groundwater, pH, Nitrate, Dissolved Oxygen, Specific Conductance
This project presents data pertaining to the water chemistry of streams around the El Verde Field Station. Hobo U26 Dissolved Oxygen Loggers and U24 Conductivity Loggers collect data at a 15 minute time interval on the Q. Sonadora, Q. Prieta and Q. Toronja, in addition to a Hobo U20 Water Level logger at the Q. Toronja site.
A tropical wave left 8-9 inches of rain near El Verde 8-28 to 8-29-14
Data a product of the Luquillo Critical Zone Observatory (LCZO)
Ecology, Hydrology, Conductivity, Oxygen, DO, Dissolved Oxygen, Temperature
The ability to quantify how fast weathering profiles develop is crucial to assessing soil resource depletion and quantifying how landscapes evolve over millennia. Uranium-series isotopes can be used to determine the age of the weathering front throughout a profile and to infer estimates of regolith production rates, because the abundance of U-series isotopes in a weathering profile is a function of chemical weathering and time. This technique is applied to a weathering profile in Puerto Rico developed over a volcaniclastic bedrock.
Key science question:
• How does stream channel morphology respond to the addition of impervious cover in a humid tropical region adjusted to frequent large storms?
Geomorphology, Urbanization, Streams
Sediment transport is an intrinsically stochastic process, and measurement of bed load in the environment is further complicated by the unsteady nature of river flooding. Here we present a methodology for analyzing sediment tracer data with unsteady forcing. We define a dimensionless impulse by integrating the cumulative excess shear velocity for the duration of measurement, normalized by grain size. We analyze the dispersion of a plume of cobble tracers in a very flashy stream over two years.
Sediment Transport, Geomorphology, Hydrograph
The purpose of this study is to understand the variations of canopy level ozone in this montane tropical rainforest. The study analyzed the ozone levels across time—hourly, monthly and seasonally. 8-hour averages were calculated to compare to US ozone standards. The ozone data was then combined with climate data to find correlations between ozone with temperature, relative humidity, precipitation, solar radiation and wind.
Data a product of USDA Forest Service -IITF:
Bisley, ozone, temperature, relative humidity, precipitation, solar radiation, wind, volatile organic compounds, nitrogen oxides, sunlight, pollution