This study was conducted in the Luquillo Experimental Forest (LEF) in the subtropical life zone of northeastern Puerto Rico. The forest is dominated by tabonuco (Dacryodes excelsa). The site receives 3500 mm of rainfall each year with a monthly mean temperature of 22.1 °C (Brown et al. 1983). Soils of the area are a complex of upland Ultisols and Oxisols (Soil survey 1995). The general topography is mountainous with deeply dissected drainage at elevations between 340 m and 460 m above sea level.
In this project we try to find out the relationship between the primary production and the soil organic carbon fractions.