There is a direct positive correlation between high amounts of plant biomass, and the nutritional quality of that biomass. In the Sahel, herbivores mainly utilize vegetation with a low protein content. An anomalous pool of warm surface water collects in the eastern southern Pacific Ocean. Upwelling of cold water off the Peruvian coast stops. Rates of decomposition are slow.
Most nitrogen is present in dead organic matter below the ground surface.
Many species are endemic to small areas of rainforest. Laterite soils are unweathered. Birds are a excellent indicator of the adverse effects of habitat fragmentation. The absence of large areas of pure hardwood forest. The absence of forest fires.