Litter Accumulation in Selected Forests of the Republic of Panama

Abstract

Accumulated litter was collected from primary and secondary tropical moist forests, and from a primary, premontane wet forest in Panama during June to August 1967 (wet-season months), and in January 1968 (a dry-season month). Weights of litter and caloric contents were greatest in the premontane wet forest. Litter accumulation and energy content increased during the dry season in two secondary, tropical moist forests. THE NET RATE of change in energy stored in an ecosystem or its parts equals the rate of income minus the rate of loss (Olson 1963). These rates may be expressed for various trophic levels or species and also for accumulated organic matter. In forests, both living and dead material accumulate large reservoirs of energy. A substantial fraction, often one-third to one-half or more of the energy and carbon annually fixed in forests, is present on the forest floor as litter. Because litter is generally related to the amount of photosynthetic machinery in the system, it can be a useful index of ecosystem productivity. Since litter fall can serve as an indicator of forest production, it is feasible that the energy content of litter accumulated on the forest floor can be used to compare levels of productivity in various forest types. Calorimetric methods, which involve measuring the amount of heat liberated by combustion of samples in oxygen-filled bombs, have been used frequently as a means of deriving energy contents of organic materials. The purpose of this paper is to report the amounts of litter collected from several selected forests in the Republic of Panama and calorimetric analyses of the material.