Scatena, F.N.; Doherty, S.J.; Odum, H.T.; Kharecha, P. 2002. An EMERGY
evaluation of Puerto Rico and the Luquillo Experimental Forest. Gen. Tech. Rep.
IITF-GTR-9. Río Piedras, PR: U.S. Department of Agriculture, Forest Service,
International Institute of Tropical Forestry. 79 p.
Abstract:
The many functions of Puerto Rico and the Luquillo Experimental Forest (the
Forest) were evaluated in units of solar EMERGY, an energy-based measure of
resource contribution and influence, defined as the energy of one type required to
produce a flow or storage of another type. Rainfall and tectonic uplift are the largest
environmental inputs into the Forest. The interaction of these inputs results in an
erosional landscape where the EMERGY of biological processes is less than the
EMERGY associated with the physical and chemical sculpturing of the landscape.
The environmental work that built the natural capital of these forests is 9 to 50 times
their current dollar market values. Of the investments evaluated in this study, the
effects associated with water extraction are the largest.
Tectonic inputs and the hydrologic cycle also provide most of the environmental
EMERGY flows in the island of Puerto Rico. The ratio of societal inputs to environmental
inputs, however, is 45 for Puerto Rico and 3.5 for the Forest. Per capita
EMERGY- use is typical of moderately developed economies, but the island has
one of the most investment-intensive, least self-sufficient economies known and
an EMERGY signature that resembles a city-state.