The spatial dynamics of native and introduced blowflies (Dipt., Calliphoridae)

The spatial dynamics of three blowfly species was investigated using a spatially extended model of density-dependent population growth and the results indicate an overall stabilizing effect. Introduction of diffusive dispersal induced a quantitative effect of damping variation in population size on the route to a one-fixed point equilibrium in the native species, Cochliomyia macellaria. On the other hand, diffusive dispersal caused qualitative shifts in the dynamics of two invading species, Chrysomya megacephala and Chrysomya putoria. In both species diffusive dispersal can produce a qualitative shift from a two-point limit cycle to a one fixed-point dynamics. Quantitatively, dispersal also has the effect of damping oscillations in population size in the invading species.

Interaction in culture medium of acttnomycetes and native fungi wtth rhizobia that form nodules in Neonotonia wighth lackley (perennial soybean)

The relationship between soil fungi and actinomycetes, with rhizobia that produce nodulation in Neonotonia wightii (perennial soybean) was studied in culture medium in order to obtain material to be used in mixed inoculations of this legume. A field experiment was designed to provide soil samples and isolate microorganisms belonging to these groups that are capable of interfering in the development of two selected rhizobium strains. Results show that the Bradyrhizobium strains used in the experiment, which are efficient in nodulation of Neonotonia wightii, are highly sensitive to substances produced in the culture medium by actinomycetes and fungi.

Search for Antifungal and Anticancer Compounds from Native Plant Species of Cerrado and Atlantic Forest

Bioactivity-guided fractionation of several bioactive extracts obtained from Cerrado and Atlantic Forest plant species led to the isolation of potent DNA-damaging piperidine 1-5 and guanidine alkaloids 6-9 from Cassia leptophylla and Pterogyne nitens respectively, two common Leguminosae from Atlantic Forest. By means of biotechnological approach on Maytenus aquifolium, a species from Cerrado, moderate DNA-damaging sesquiterpene pyridine alkaloid 10-11 was isolated. Bioassay-guided fractionation on Casearia sylvestris, a medicinal plant species found in Cerrado and Atlantic Forest, led to the isolation of clerodane diterpenes 12-13 which showed effect on DNA. In addition, we have reported several interesting potent antifungal iridoids: 1β-hydroxy-dihydrocornin (14), 1α-hydroxy-dihydrocornin (15), α-gardiol (16), β-gardiol (17), plumericin (18), isoplumericin (19), 11-O-trans-caffeoylteucrein (20); ester derivative: 2-methyl-4-hydroxy-butyl-caffeoate (21), amide N-[7-(3'.4'-methylenedioxyphenyl)-2Z, 4Z-heptadienoyl] pyrrolidine (22) and triterpene viburgenin (23).

Termite pests in eucalyptus forests of brazil

The termite problem in eucalyptus forest plantations in Brazil has been registered since 1908. The main termite pests can be separated in four groups: a) seedling/sapling termites; b) heartwood termites; c) bark termites and d) wood termites. The termites in the first group attack root and stalk bases of young eucalyptus plants. The most common species are Syntermes spp. and Cornitermes spp. and they are a serious obstacle to early eucalyptus developing. The heartwood termites attack formed trees destroying eucalyptus heartwood. Coptotermes testaceus is the most cited species in reports, but more species probably occur. Plant mortality caused by seedling/sapling termites vary of 10-70 %. There are not effective control methods to heartwood termites. The main seedling/sapling termite control strategy is the chemical barrier around root systems of plants. Nowadays, studies are being carried out to determine monitoring systems to termite infestations. Early results indicate that proportionally, few areas really need insecticide application, due to spatial distribution of termites to be aggregated. Therefore, it is necessary to develope techniques rationalizing insecticide utilization in eucalyptus plantations, to keep production systems feasible and to be suitable for environmental exigencies.

Comparison of the population structure of the fiddler crab Uca vocator (Herbst, 1804) from three subtropical mangrove forests

The population structure of U. vocator was investigated during a one-year period in three mangrove forests in southeast Brazil. The study specifically addressed comparisons on individual size juvenile recruitment and sex-ratio. The structure of the mangrove forests, i.e. density, basal area, and diameter, and the physical properties of sediments. i.e. texture and organic matter contents, were also examined. A catch-per-unit-effort (CPUE) technique was used to sample the crab populations using 15-min sampling periods by two people. Males always outnumbered females, probably due to ecological and behavioural attributes of these crabs. The median size of fiddler crabs differed among the sampled populations. The mangroves at Indaiá and Itamambuca showed higher productivity than those at Itapanhaú, where oil spills impacting the shore were reported. Marked differences were found regarding individual size, either their size at the onset of sexual maturity or their asymptotic size, suggesting that food availability may be favouring growth in the studied populations.

Alien fishes in lakes of the Doce river basin (Brazil): Range, new occurrences and conservation of native communities

The present study shows the distribution of alien fish species in tropical lakes in the middle Doce river basin, southeastern Brazil, obtained from a rapid assessment program. The causes for their introductions were sport-fishing improvement in some specific lakes and aquaculture in the studied basin. Presently, these species have a wide distribution occurring in 41 of the 54 lakes studied, representing an actual threat to regional native fish community. The natural connection among lakes and streams during the rainy season and the dispersal mediated by local people are the main invasion agents for alien fishes. The success of these invaders is probably due to absence of pre-existing effective competitors or top-predators in the invaded communities. We consider that the eradication of alien fishes by means of the available management tools may be very difficult due to the large number of lakes invaded and to the wide spectrum of lake conditions and resources exploited by these alien species. We recommend the use of environmental education as a tool to stop the human-mediated dispersion of aliens and to improve conservation of native fish community in lakes where these alien species are not present yet. © 2004 Instituto de Ciências Biológicas - UFMG.

An integrated approach to identification and conservation of medicinal plants in the tropical forest - A Brazilian experience

An integrated and interdisciplinary research programme with native medicinal plants from tropical forests has been performed in order to obtain new forest products for sustainable use in regional markets vis-à-vis ecosystem conservation. For the success of this programme ethnopharmacological studies are very important with respect to (i) identification of useful plants including medicinal and aromatic species; (ii) recuperation and preservation of traditional knowledge about native plants; and (iii) identification of potential plants with economic value. The plants are selected with a view to evaluate efficacy and safety (pharmacological and toxicological studies), and phytochemical profile and quality control (phytochemical and chromatographic characterization). These studies are very important to add value to plant products and also to mitigate unscrupulous exploitation of medicinal plants by local communities, since multiple use of plants represents an excellent strategy for sustaining the tropical ecosystem through ex situ and in situ conservation. Thus, conservation of tropical resources is possible in conjunction with improvements in the quality of life of the traditional communities and production of new products with therapeutic, cosmetic and 'cosmeceutic' value. © NIAB 2005.

Maturidade fisiológica das sementes do ipê amarelo, Tabebuia chrysotricha (Mart. Ex DC.) Standl

Ipê amarelo Tabebuia chrysotricha (Mart. Ex DC.) Standl. is a native forest species that presents heavy and durable wood: it is common to be used for urban arborization. The species is latte secondary and heliophyta. Occurs from Espirito Santo State until Santa Catarina in the Pluvial Atlantic Forest (Mata Atlântica). The seedling production is hard because their seeds have short longevity after dispersion, and so due to the difficulty to harvest winged seeds that are quickly dispersed by the wind. The present study was carried out to evaluate the physiological maturity of Ipê Amarelo seeds, to establish the best moment to harvest them. The study was to accompany the maturation of 100 fruits in just beginning development, from eleven different trees. Morphological characteristic measures were made weekly, with fruits still on trees, starting from the second week development when fruits presented the following averages: 6.3 cm length, 0.71 cm thickness, and 0.82 cm width. From the sixth week of fruit development we harvest them to proceed the germination test, water content rate, and electric conductivity test. The germination has begun by the seventh week development with 28% of germinated seedlings. The highest germination rate happened by the eighth week development, with 74.5% of germinated seedlings and on the ninth week the rate decrease to 65.5%, when the seeds were already in dispersion. Through the electric conductivity test the highest value obtained was 378.06 μS.g -1.cm -1 on the seventh week development and the lowest one was 183.28 μpS.g -1.cm -1 on eighth week. These results support those obtained in the germination test, because as higher is the electric conductivity of seeds, as higher is their deterioration level. Finally, the study allows concluding that the physiological maturation of ipê amarelo seeds has occurred before dispersion close to the eighth week development when fruits presented the following averages: 22.2 cm length, 1.37 cm width, and 1.05 cm thickness; water content rate was 61.8% and electric conductivity was 183.28 μS.g -1.cm -1. In that moment, the fruits presented greened brown coloration and started to show fissures.

Ant fauna (Hymenoptera: Formicidae) in Magnoliophyta native to the Atlantic forest

The aim of the study was to analyze the preferences of ant species visiting the trunks of eight species of Magnoliophyta, belonging to the families Fabaceae, Arecaceae, Myrtaceae, Melastomataceae and Euphorbiaceae, located in a fragment of the Atlantic Forest in southeastern Brazil. A total of 101 ant species, belonging to eight subfamilies and 32 genera, were sampled during the 12-month collection period. Close to 30% of the ant species can be considered arboreal, and the others are species that nest in the ground and use trees only for foraging, which can be occasional, as in the case of the Ecitoninae sampled in Arecaceae and Euphorbiaceae. Pachycondyla mesonotalis was the only species collected on all the Magnoliophyta, whereas Camponotus rufipes, Acromyrmex niger and Crematogaster spp., were found on 87.5% of the trees analyzed. No strong similarities were found, using the Jaccard Index, among plant species in the same family of Magnoliophyta based on the visiting ants, except for the Euphorbiaceae species. This result is probably related to the presence of extra-floral nectar, which is very attractive to ants and characteristic of this family.

Análise da evolução da paisagem no entorno da represa dos rios jaguari e jacareí, estado de são paulo, com base em sensoriamento remoto e SIG

The primary objective of this study is to evaluate by means of remote sensing and GIS, the landscape evolution around the Jaguari and Jacareí River Dam, located in the eastern section of the State of São Paulo, Brazil. For this purpose we used LANDSAT 5/YM and CBERS-2/CCD images from 1984/1985 and 2006, respectively, considering the following classes of land use: forest, cultivated forest, agriculture, urban areas and water bodies. The two selected dates reflect important changes in the region such as the installation of the dam and subsequent urbanization of parts of its margins and the enlargement of the Fernão Dias Federal Highway, which contributed to an increase of areas of anthropic activities in the studied region. The results also indicate an increase in areas covered by native and planted forests, thus confirming a similar trend in other areas of the State of São Paulo.

Mutagenic effect of native species of the Brazilian Cerrado with anti-ulcerogenic activity

Neea theifera Oerted (Nyctaginaceae), Guapira noxia Linn. (Nyctaginaceae) and Hancornia speciosa Gomes (Apocynaceae) are plant species found in Brazilian Cerrado used popularly for the treatment of gastric ulcers. Here they are assessed for mutagenic activity by analysis of the reverse mutations induced in Salmonella typhimurium strains TA100, TA98, TA102 and TA97a, by extracts of the plants, with and without metabolic activation. Methanol and chloroform extracts of N. theifera and G. noxia and methanolic and aqueous extracts of H. speciosa were tested at five different concentrations. It was found that only the methanolic extract of H. speciosa exhibited a positive mutagenic effect, on strains TA98 and TA100 in the absence of metabolic activation. The phytochemical analysis of the species suggested that condensed tannins are the main compounds responsible for the observed effect.

Evaluation of soil management and use in an Ultisol in a guava orchard in comparison with a sugarcane field and native forest area

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Indicators of soil degradation in urban forests: Physical and chemical parameters

The fragmentation of forest habitats in urban areas has aroused increasing interest in recent years according to the growing environmental problems. The fragmentation of theses ecosystems is caused, in general, by the pressure of housing, agriculture and industry, causing losses in biodiversity and problems of soil degradation in the border areas of theses remnants. The establishment of indicators of soil degradation becomes essential for the implementation of conservation and reclamation. This study analyzes physical and chemical characteristics of soil under different forms of vegetation in the forest surrounding the Quilombo Forest, located in Campinas/SP - Brazil, and examines the possibility of using these indices as indicators of environmental degradation in urban remnants. The parameters analyzed were: specific weight natural (γn), specific weight of solids (γs) Ca, P, K, Mg, pH, organic matter, H + Al, Sum of Base (SB) Percent Base Saturation (V%), Cation Exchange Capacity (CEC). The study shows that in general the different forms of land used in the study area significantly changed (or according to) the physical aspects of soil The porosity and voids of the soil stood out as the best indicators of soil physical degradation in the layer 0-20 cm deep. In relation to chemical indices, the soil under the cultivation of cane sugar had a significantly higher pH, K, Ca, Mg and sum of bases. The areas of forest showed higher levels of phosphorus, organic matter and CEC, indicating the importance of maintaining vegetation and replacement for the cycling of organic matter.

Edible coatings from native and modified starches retain carotenoids in pumpkin during drying

The goal of this study was to evaluate the effect of edible coating pre-treatments on the retention of provitamin A during pumpkin drying. The coatings used were based on native and modified maize and cassava starch. To evaluate the effects of these coatings, slices of 'Dry Rajada' pumpkin were dried at 70 °C both with and without starch coatings applied at 30 and 80-90 °C. Carotenoid content was determined through HPLC using a C 30 column. Significant losses (12-15%) of trans-α-carotene and trans-β-carotene were observed when slices were dried without the coating. Significant improvement of carotenoid content was observed for dehydrated slices that were previously coated with a native maize starch solution at 90 °C, as well as with a modified maize starch solution at 30 °C and also with a modified cassava starch solution at 90 °C. The application of these starch solutions probably produced a more uniform film that adhered to the slices, minimizing carotenoid degradation during pumpkin drying and, as a consequence, resulting in a product that can be considered a good source of provitamin A. © 2012 Elsevier Ltd.