On Biomass and Trophic Structure of the Central Amazonian Rain Forest Ecosystem

Abstract

The importance of litter in the total energy flow dynamics of a central Amazonian rain forest near Manaus, Brazil, is discussed. The study area is located in the hinterland of Manaus between the Rio Negro and the Amazon. Its substrate is Tertiary sediment. The area receives 1771 mm rainfall per year, and the soil is classified as yellow latosol. The forest comprises 93,780 dicotyledonous trees and palms per hectare reaching 38.10 meters in height. Over 500 species of palms and dicotyledonous trees above 1.5 m. in height are identified for a 2000 sq. m. plot. The estimate for fresh living dicotyledonous tree and palm biomass is 939.5 metric tons per hectare consisting of 1.9% leaves, 49.7% stems, 21.3% branches and twigs, and 27.1% roots. Lianas, vascular epiphytes, and parasites are estimated to comprise 46.2 mt/hectare in the fresh state. At the soil surface there are 59 mt/hectare of fresh litter. Living animal biomass is about 200 kg/hectare of which half is soil fauna. The high proportion of soil fauna, the type of humus, the decomposition of litter, the apparent dependence of soil fauna on fungi, and the low nutrient content of litter are all factors which strongly support a consumer food chain based almost entirely on dead organic matter. The fungi play a decisive role in concentrating the otherwise limited nutrient resources.

Short-term sodium inputs attract microbi-detritivores and their predators

“…BFWs are donor-controlled and comprised of microbes, microbi-detritivores that consume plant detritus and associated microbes, and their predators that interact and ultimately decompose ca. 90% of the productivity (uneaten plant biomass) in green food webs (Fittkau and Klinge, 1973;Coleman et al, 1996;Wardle, 2002;Decaëns, 2010). Consequently, understanding Na-limitation and its effects on BFWs can facilitate our understanding of broad geographic community and decomposition patterns.…”

Daytime turbulent exchange between the Amazon forest and the atmosphere

“…Thus, the most important canopy structural characteristics for exchange processes are leaf and branch area rather than the total biomass, relevant to the biomass heat storage problem (Moore and Fisch, 1986) or to the problem of estimating the net ecosystem productivity (Odum, 1971). At the Ducke Forest Reserve, near Manaus in the central Amazon basin (2'57'S, 59O57'W), the average height of the canopy is near 30 m, with the average leaf biomass remaining nearly constant down to 15 m (Fittkau and Klinge, 1973). The largest trees have much of their leaf and branch volume concentrated in the upper canopy.…”

Invasive alien plants affect grassland ant communities, colony size and foraging behaviour

“…Ants are one of the most widely distributed and abundant group of insects and they usually have high species diversity and biomass, as well as numerical dominance in various habitats and they interact with many organisms at every trophic level (Fittkau and Klinge 1973;Agosti et al 1994Agosti et al , 2000. Ants have recently received a great deal of attention as a possible use as an indication group due to their sensitivity to changes in the environment (Agosti et al 2000;Andersen et al 2002;Andersen and Majer 2004).…”