Caracterização de serrapilheira em agroecossistemas na Amazônia Central.

Este estudo teve como objetivo comparar o estoque de serrapilheira em ecossistemas naturais (floresta primária) e agroecossistemas (monocultivos e policultivos), bem como avaliar algumas características químicas dessas serrapilheiras e do solo, nas condições tropicais amazônicas

Microclimate 1997-1999 in primary forest, secondary forest and agroforestry systems in central Amazonia.

Rainfall, average maximum and minimum air temperature, and relative air humidity as measured at the Embrapa weather station all show that 1997 was a strong El Nino (ENSO) year.bitstream/item/181106/1/ID-5199-34-49.pdfFinal Report 1996-1999

Litter production, litter stocks and decomposition coefficients in a central Amazonian rain forest, a secondary forest and agroforestry systems.

Fine litter fall and stocks were determined from July 1997 to March 1999 in an area of primary rain forest (FLO), a 13-year old secondary forest (SEC), and two polyculture systems (agroforestry; POA and POC) in central Amazonia Brazil.Final Report 1996-1999

Structure and function of soil fauna communities in Amazonian anthropogenic and natural ecosystems.

The aim of our study was to judge the soil biological conditions in the plantations with regard to the aspired sustainability of agricultural and forestry systems

Reassessing climate and pre-Columbian drivers of paleofire activity in the Bolivian Amazon

A 50,000-year-old sediment core record from Laguna Chaplin is reanalyzed to explore potential paleoecological methods to detect the extent of pre-Columbian disturbance in the Bolivian Amazon. High-resolution (sub-centennial) macrocharcoal data are analyzed using statistical algorithm software including Regime Shift Detection and CHAR Analysis to detect changes in past fire regimes. These data are compared with existing charcoal records from throughout the Bolivian lowlands to provide a regional scale context of past biomass burning. During the mid-Holocene, changes in precipitation are the dominant driver of fire activity and biomass burning at Laguna Chaplin and across the Bolivian lowlands. During the late Holocene, increased fire activity across ecosystems ranging from fire-adapted to fire-intolerant forests is attributed to the apex of pre-Columbian activity. These data suggest human-caused ignitions during the late Holocene are the driving factor of regional scale fire activity in the Bolivian lowlands. After ca. 650 cal yr BP, there is an increase in biomass burning and fire frequency synchronous with the expansion of Moraceae/Urticaceae pollen (>50%) at Laguna Chaplin. This occurs during the time-transgressive southward expansion of the rainforest boundary, during the apex of pre-Columbian activity in the region. The increase in biomass burning at Laguna Chaplin is reflected at other sites in the region with known human occupation histories. The presence of Zea mays ca. 970 to 170 cal yr BP indicates maize cultivation is practiced in the immediate vicinity surrounding Laguna Chaplin. The simultaneous increase in fire activity with the expansion of the less flammable humid rainforest vegetation suggests human fire management practices. These data are interpreted as the use of frequent, low severity, human-caused fires to clear the croplands from encroaching rainforest vegetation. Despite evidence of pre-Columbian fire management during the late Holocene, vegetation and fire data indicate the extent of human-landscape modification and fire management at Laguna Chaplin, is not enough to inhibit the climate-driven regional forest expansion of the savanna-rainforest ecotonal boundary to its most southern extent in the last 50,000 years. This study demonstrates the utility of applying a multi-proxy, high-resolution paleoecological method to disentangle climate and pre-Columbian disturbance in the Bolivian Amazon

The function of the soil macrofauna in decomposition processes in Central Amazonian polyculture systems and forests.

A study of macrofauna and decomposition in three central Amazonian ecosystems (a primary and a secondary forest and two polyculture tree plantations) has shown the high importance of the macrofauna for the litter decomposition

Abundance, biomass and diversity of the soil fauna in degraded areas under recuperation in the Central Amazon Region.

The soil fauna plays an important role in the stability of decomposition processes and as a result its abundance, biomass and species composition, may influence the nutrient cycles in agroecosystems

Floodplains in the Peruvian Amazon region as faunal sources for agrarian areas

In this paper, the effect of slash and burn of a primary forest on the epigeic fauna are studied as well as its behaviour of colonization in Amazonian agriculture zones and distribution in its original habitats. It is supposed that, natural inundation areas and forests of a region represent the original habitats of an agrarian fauna. Strategies of colonization of the Carabidae were compared to those of Staphylinidae, Elateridae, Gelastocoridae, Isopoda, Diplopoda and Aves. Inundation areas without forest (Litoraea) are found to be the most important faunal sources for the agrarian areas, with most of the flying arthropod species and birds originating from there. Numerous species of the non-flying macroarthropods originate from the forest. Litoraea and anthropogenic cultivation areas as succesional ecosystems are more similar in structure, dynamics and microclimate when compared to the primary forest. In anthropogenic ecosystems, the principal cause of reduced species numbers is the lack of structrual diversity and the microclimate. This results in a reduction of the biocenotic connex. [in German

Auswirkung von Oberflaechenbehandlungen auf das Ermuedungsverhalten von TiAl6V4 und 42 CrMo 4 bei erhoehter Temperatur

Available from TIB Hannover: DR 9493 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman