The soil climate regimes of Puerto Rico - reassessment and implications

Abstract

The soil climate regimes of Puerto Rico were evaluated and their implications discussed. The main objective of this project was to evaluate soil moisture and temperature regimes in Puerto Rico. Knowledge of the soil climate is important for three major reasons: (1) to understand the development and formation of specific soils; (2) to consistently classify and map soils accurately; and (3) to apply that knowledge to the use and management of soil-plant-water systems (Mount et al., 1992, 1994). Average monthly precipitation and temperature data from 90 weather stations of the U.S. Weather Service were used to compute the soil moisture and temperature regimes using the Newhall Simulation Model program version 1.0 (Van Wambeke et al., 1991). The results of the model were evaluated with soil moisture and temperature data of five weather stations of the USDA-Natural Resources Conservation Service. The study confirms the existence of soils with an aridic moisture regime in the island. The Newhall Simulation Model identified an area of 25,450 ha with an aridic moisture regime along the south coast and on Mona Island. This is the first recognition of the aridic moisture regime in Puerto Rico. An area with ustic soil moisture regime in the northwest corner of the island was also identified. This area is currently recognized as having a udic moisture regime. The isomesic temperature regime previously identified at the Caribbean National Forest was not confirmed by the Newhall Simulation Model. The isothermic temperature regime previously identified in areas above 600 m above sea level was identified by the model in areas above 900 m. As a result of these changes in the soil climate regimes, approximately 100 soil series need to be reclassified and new soil series will have to be proposed.