Amazonian biodiversity and protected areas: do they meet?

Protected areas are crucial for Amazonian nature conservation. Many Amazonian reserves have been selected systematically to achieve biodiversity representativeness. We review the role natural-scientific understanding has played in reserve selection, and evaluate the theoretical potential of the existing reserves to cover a complete sample of the species diversity of the Amazonian rainforest biome. In total, 108 reserves (604,832 km²) are treated as strictly protected and Amazonian; 87 of these can be seen as systematically selected to sample species diversity (75.3% of total area). Because direct knowledge on all species distributions is unavailable, surrogates have been used to select reserves: direct information on some species distributions (15 reserves, 14.8% of total area); species distribution patterns predicted on the basis of conceptual models, mainly the Pleistocene refuge hypothesis, (5/10.3%); environmental units (46/27.3%); or a combination of distribution patterns and environmental units (21/22.9%). None of these surrogates are reliable: direct information on species distributions is inadequate; the Pleistocene refuge hypothesis is highly controversial; and environmental classifications do not capture all relevant ecological variation, and their relevance for species distribution patterns is undocumented. Hence, Amazonian reserves cannot be safely assumed to capture all Amazonian species. To improve the situation, transparency and an active dialogue with the scientific community should be integral to conservation planning. We suggest that the best currently available approach for sampling Amazonian species diversity in reserve selection is to simultaneously inventory indicator plant species and climatic and geological conditions, and to combine field studies with remote sensing.     

The Brazilian experience of sugarcane ethanol industry

Biomass has gained prominence in the last few years as one of the most important renewable energy sources. In Brazil, a sugarcane ethanol program called ProAlcohol was designed to supply the liquid gasoline substitution and has been running for the last 30 yr. The federal government’s establishment of ProAlcohol in 1975 created the grounds for the development of a sugarcane industry that currently is one of the most efficient systems for the conversion of photosynthate into different forms of energy. Improvement of industrial processes along with strong sugarcane breeding programs brought technologies that currently support a cropland of 7 million hectares of sugarcane with an average yield of 75 tons/ha. From the beginning of ProAlcohol to the present time, ethanol yield has grown from 2,500 to around 7,000 l/ha. New technologies for energy production from crushed sugarcane stalk are currently supplying 15% of the electricity needs of the country. Projections show that sugarcane could supply over 30% of Brazil’s energy needs by 2020. In this review, we briefly describe some historic facts of the ethanol industry, the role of sugarcane breeding, and the prospects of sugarcane biotechnology     

Potential Biomass Accumulation in Amazonian Regrowth Forests

Biomass accumulation in the secondary forests of abandoned pastures and slash-and-burn agricultural fallows is an important but poorly constrained component of the regional carbon budget for the Brazilian Amazon. Using empirical relationships derived from a global analysis, we predicted potential aboveground biomass accumulation (ABA) for the region's regrowth forests based on soil texture and climate data. For regrowth forests on nonsandy soils, the globally derived relationship provided a nearly unbiased linear predictor of Amazonian validation data consisting of 66 stands at seven sites; there was no significant difference between stands that regrew following use as pasture land and those that regrew following slash-and-burn agriculture. For regrowth forests on nonsandy soil, the 1 sigma error range of our ABA model was 58%–171% for the Amazonian validation data. For regrowth forests on sandy soils, the validation data were limited to 19 stands at one site, and the globally derived relationship was substantially biased multiplicatively and nonlinearly. Hence we developed a regional refinement by adding to our validation data ABA values from the two Amazonian sites with sandy soil that had previously been included in the global analysis. Based on a conservative jackknife goodness-of-fit assessment (leaving out one site at a time), we calculated a 1 sigma error range of 42%–158% for our sandy soil Amazonian regrowth forest ABA model. We present our predictions of potential regrowth forest ABA as a set of 0.5° resolution maps for the region at 5, 10, and 20 years following abandonment. Received 6 September 2000; accepted 19 April 2001.     

Knowledge and use of fungi by a mycophilic society of the Venezuelan Amazon

This paper reports on the knowledge and useful applications of various fungi by the Hotï, a recently contacted Native American society inhabiting the Sierra Maigualida region of the Venezuelan Amazon. At least 31 folk taxa of fungi are esteemed as sources of nutrition, powerful media for hunting magic, protective charms against black magic, human medicinal agents, or body adornments. Even though the results presented here probably do not exhaust the total number of species known and used by them, they nevertheless suggest that the Hotï constitute one of the rare mycophilic societies in the Venezuelan Amazon. Further research is needed in order to obtain a more complete picture of the complexity of humanfungi relationships in this society.     

Fish of the Amazonian IgapÔ: stability and conservation in a high diversity-low biomass system

Water depth in the Amazon basin can differ by more than 11 m between low and high water periods in the annual cycle. When the water is high, the forest streams inundate the surrounding low-lying forest creating vast lakes. Where the water originates from the forest it is rich in humic acids and low in dissolved nutrients. Such waters are termed blackwaters. Igapó is the specialized inundation forest of blackwater regions. Until recently it was generally held that the blackwater fauna was impoverished and of low biomass. However, recent studies have shown that these waters hold a specialized fauna living within and upon allochthonous input from the forest. Within submerged litter banks a diverse ichthyofauna forming dense local populations has been found.
Information on the spatial organization, population density and food web of this fauna will be presented. It is argued that this community is highly vulnerable to deforestation and its long-term future can only be assured if the forest is conserved. This is not to suggest that these fish are not adaptable to disturbance as the community has evolved to live with changing water levels and the loss of submerged wood and leaf-litter habitat. It is a remarkable example of a climax community exhibiting high diversity and low total population sizes within a variable habitat. Its conservation is of economic importance to the local human population whose diet includes a high proportion of fish.