Carajas National Forest Research Articles

Potential of Copaifera spp. oleoresin for sustainable extraction in the Eastern Amazon

Copaifera oleoresin is an important traditional non-timber forest product in the Amazon; however, the Carajas National Forest has no plans to harvest this product to benefit extractive families. The objective of this study was to determine Copaifera oleoresin extraction potential in the Carajas National Forest, Eastern Amazon, identifying variables that could increase the chances of finding oleoresin. We mapped 129 trees and formulated a multiple logistic regression model (logit) with the collected variables: diameter at breast height (DBH), tree crown, tree health, presence of termites, and presence of damage or bifurcation. Among the mapped trees, we perforated 50 trees to harvest the oleoresin. Most of the oleoresin production occurred in trees with a DBH between 50 and 75 cm. The logit model predicted that an increase in DBH, dense crown, unhollowed trunk, and presence of damage or bifurcation increased the chances of oleoresin extraction, whereas termites did not. The model could contribute to the sustainable management of forest resources by avoiding random perforation of trees and establishing rational routes and cycles of extraction. Since the variables are easily measured, the model can be continuously used for future extractions.

Effects of mining and reduced turnover of Ephemeroptera (Insecta) in streams of the Eastern Brazilian Amazon

Mining operations can cause environmental alterations that have a major impact on aquatic organisms. In the present study, we analyzed the effects of mining operations on the environmental heterogeneity of streams in the eastern Brazilian Amazon, and the beta diversity (and components) of the local communities of the order Ephemeroptera. We tested three hypotheses: (a) mining activities reduce the environmental variation of streams; (b) altered streams have lower beta diversity, and (c) environmental variables influence the genus richness and abundance of ephemeropterans. The ephemeropterans were sampled in the Carajas National Forest in the dry season over 3 years. Streams were sampled in areas near the extraction of iron ore (16) and in pristine environments (8). The beta diversity was estimated based on the occurrence and abundance approaches. We recorded 2259 individuals and 32 genera. The comparative assessment of environmental variables indicated that environments altered by mining have higher total manganese and iron concentrations than preserved environments. Environmental variables influenced ephemeropteran communities, and the analysis of the components of the beta diversity indicated a higher turnover of ephemeropterans in preserved streams, which implies that species substitution rates are higher in preserved streams than in altered streams. These results indicate that the substitution of species in preserved streams is limited spatially, probably linked to the sensitivity of the organisms to oscillations in the environmental variables occurring in impacted environments. IMPLICATIONS FOR INSECT CONSERVATION: The results indicated that possibly the changes brought about by mining activities restrict the turnover of species between the preserved and altered areas, and only species tolerant to these changes were established. Over time and with the advancement of mining activities may occur the local exclusion of the most sensitive species and homogenization of the composition formed by more tolerant and less relevant conservation species.

The impact of glyphosate herbicides on soil microbial activity from the Carajás National Forest

The objective of this study was to evaluate the impact of different glyphosate‑based herbicide formulations on microbial activity of soils from Carajas National Forest. We tested three formulations of glyphosate, i.e., Roundup Original®, Roundup Ultra® and Roundup WG® that were applied in five doses: 0; 240; 480; 720 and 1440 g of active ingredient in acid equivalent ha-1, with four replications. Herbicides were sprayed on pots containing 500 g of soil derived from the 0-10 cm layer of the study site. We determined the carbon from microbial biomass (C-MB), microbial respiration rate (MR) and metabolic quotient (qCO2) at one and 28 days after herbicide application. No treatment affected the C-MB and MR at one and 28 days of incubation. There was no difference for qCO2 at any dose of Roundup Ultra® and WG® formulations at one and 28 days of incubation. However, the qCO2 was inhibited by the Roundup Original® at one day post treatment. This parameter was normalized at 28 days after herbicide application. The data indicate that no one of the treatments tested cause significant impact on soil microorganisms of the Carajas National Forest, suggesting that herbicide-based invasive weed control could be used.

KOBAYASIELLA SPECIES FROM CARAJÁS NATIONAL FOREST, AMAZONIA, BRAZIL

Species belonging to the genus Kobayasiella Lange-Bertalot may occur over a narrow range of environmental conditions. The genus may be common in diatom communities of acidic, oligotrophic and dystrophic habitats. In this study observations on valve ultrastructure and descriptions of four Kobayasiella species from pristine and altitudinal environments of Carajas National Forest, Brasil is presented. These taxa include Kobayasiella grandis (Metzeltin & Lange-Bertalot) Lange-Bertalot and three new species—Kobayasiella brasiliana Kociolek & Burliga, sp. nov., Kobayasiella carajasiana Burliga & Kociolek, sp. nov., and Kobayasiella xikriniana, Burliga & Kociolek, sp. nov. The first SEM observations of K. grandis are presented along with LM and SEM observations on the three new species, and compared with previously described taxa. The genus may have more species that are endemic to specific regions than cosmopolitan species.

Atropelamentos de vertebrados na Floresta Nacional de Carajás, Pará, Brasil

Vários pesquisadores têm avaliado impactos de estradas. Estes podem envolver aspectos paisagísticos, degradação do solo, poluição do ar e impactos sobre a fauna, como atropelamentos. Na estrada Raimundo Mascarenhas, que atravessa a Floresta Nacional de Carajás (ca. 400 mil hectares), há intenso tráfego de veículos automotores. O objetivo deste trabalho foi testar se há diferenças entre trechos da estrada, em três escalas espaciais; se há alteração ao longo dos anos; se alguns táxons são mais freqüentemente atropelados, e se a freqüência de atropelamentos aumenta com a precipitação mensal. Analisamos a freqüência de atropelamentos de vertebrados de abril/2003 até outubro/2006 ao longo dos 25 km iniciais da estrada. Registramos 155 atropelamentos. O número de atropelamentos diminui ao longo dos anos (P=0,01), e com a distância do início da estrada (P=0,0002). Serpentes (Ophidia) e gambás Didelphis marsupialis foram mais atropelados (7,5/ano), seguidos de aves, raposas Cerdocyon thous, quatis Nasua nasua, roedores (Rodentia), e não identificados (4,9/ano); cuíca Marmosops sp., tapeti Sylvilagus brasiliensis, guariba Alouatta sp., irara Eira barbara, jabuti Geochelone sp., lagartos (Lacertilia) e macaco prego Cebus apella (1/ano). Não houve relação significativa entre o número mensal de atropelamentos e a precipitação mensal.