Coeffcients of herdability and relatedness in a forest fragment of Araucaria angustifolia (Bertol.) Kuntze using genetic markers

Methods based on genetic markers to estimate the coefficient of heritability in natural populations are important to understand the effects of natural selection on inheritance of quantitative traits. The objective of this study was to investigate the genetic control of the trait plant height in a fragmented population of Araucaria angustifolia. This study was conducted in a forest fragment of 5.4 ha of area, located in the State of Parana, Brazil. Estimates of heritability were performed using data from genotypes and height of regenerating individuals of the population. Four methods to estimate the relatedness between pairs of individuals (RITLAND, 1996; LYNCH; RITLAND, 1999; QUELLER; GOODNIGHT, 1989; WANG, 2002) for three distances (without criteria, 25 and 50 m) were used. The coefficient of heritability estimated using the estimator of relatedness of Ritland (1996), suggest that the genetic control of the trait height is low in the regeneration, thus the natural selection as well as the artificial selection have a low potential to change the mean of the population. The estimates based on the other methods to calculate the relatedness presented low precision, indication that these methods are not adequate for the data used.

DIFFERENTIATION OF ARBOREAL VEGETATION IN THREE SECTORS OF A FOREST FRAGMENT RELATED TO ITS HISTORICAL DISTURBANCES

Forest fragmentation is one of the main causes of biodiversity loss, directly affecting the ecological processes. This study aimed to evaluate tree diversity, structure, and composition parameters in three sectors of a forest fragment with distinct disturbance records. The arboreal vegetation was evaluated in twenty-four 10 × 10 m plots, sampling a total of 1,228 living individuals. We calculated Shanon’s diversity index, Pielou’s equability, and jackknife estimators of first and second orders. The sampled individuals were distributed in diameter classes and the importance value (VI) was calculated for each species. It was made a Detrended Correspondence Analysis (DCA) to verify whether there were significant distinctions between the sectors. It was noticed that the sector where there was clear cutting and vegetation burning in a recent past had higher abundance and richness but also the worst equability. That corresponds to the effects of perturbation as confirmed by the tree diameters and the presence of species of greater importance value. The sector that had no record of disturbance, situated in a location with greater variety of microenvironments, presented diversity, structure, and composition consistent with a no disturbance scenario. The other sector, which did not have clear cutting, was subjected to cattle trampling presented ecological parameters consistent with the absence of major disturbances. On the other hand, this third sector had the smallest environmental diversity, which puts this last sector in an intermediate situation.

Brazilian savanna forest : conservation, medicinal reservoir and bioprospecting

This study aimed to analyse the Brazilian savanna forest from a Legal Reserve (LR) area from a perspective of conservation, reservoir of organic carbon and medicinal biomass for a prospective use of native medicinal plants. An ethnobotanical and ethnopharmacological survey was carried out close to a community settled in the rural area in the south of Tocantins, being selected 9 of the most cited species (cajuí- Anacardium othonianum; inharé-Brosimum gaudichaudii; jatobá-Hymenaeae courbaril; jenipapo-Genipa americana, aroeira-Myracrodruon urundeuva; negramina-Siparuna guianensis; barbatimão- Stryphnodendron obovatum; assa peixe-Vernonia brasiliana, embaúba-Cecropia pachystachya). Crude foliar extracts were subjected to a preliminary phytochemical prospection and triage of secondary metabolites with antimicrobial activity of potential interest in health and familiar agriculture. Phenolic compounds, terpenes and flavonoids were detected in the extracts of most species, which suggests the presence of antimicrobial, antioxidant and anti-insect activities. It was evident the need to better know the LR as a reservoir of medicinal biomass in an area under ecological tension where 35% (610ha) of the property is LR and should be protected by law. Therefore, a forest inventory of live woody species was performed using the allometric or indirect method. This identified a rare remnant of Semidecidual Seasonal Forest amidst the largest world savannah, the Cerrado biome. An analysis of the forest average productivity per basal area (m².ha), aerial live biomass (ton.ha-1) and carbon stock was carried out. The forest fragment was considered relatively rich in species and diversity, although showing signs of disturbance and dominance by a few species. Its horizontal structure suggests biotic regeneration conditions. It is an important reservoir of medicinal plants. Of the families (57.5%) presenting medicinal species, 19 from a total of 33 are represented in the area and contain 44% (27) of the total species (61) and 63% (432) of the total individuals catalogued. Medicinal species have ecological importance for the equilibrium of the local flora and represent 80% of the 10 species with higher Importance Value Index (IVI): Tetragastris altissima, Chrysophyllum marginatum, Oenocarpus distichus, Sclerolobium paniculatum, Simarouba versicolor, Alibertia macrophylla, Siparuna guianensis, Maprounea guianensis, Licania parvifolia e Physocalymma scaberrimum. Medicinal productivity was high for this type of phytophysionomy: 183,2 ton. ha-1 of biomass and 91,51 ton. ha-1 of carbon representing 66% of the total biomass and carbon of this Cerrado forest. From this stage S. guianensis (Siparunaceae) was selected for performing bioassays in order to verify its biological activity against microorganisms of health and agricultural relevance. This is a native aromatic medicinal plant recommended as priority for conservation, with local popular medicinal validation and availability of medicinal feedstock (3300 Kg.ha-1), with the foliar fraction giving 38Kg/ha of crude extract and 5L/ha of essential oil. Foliar crude extracts and essential oil were obtained and tested in vitro using a disk diffusion bioassay. Different concentrations of these natural products were tested against gram-positive bacteria (Staphylococcus aureus ATCC 29213), gram-negative bacteria (Escherichia coli ATCC 25922 and ATCC 35218; Pseudomonas aeruginosa ATCC 10145) and fungi (Candida albicans ATCC 6258 e Fusarium oxysporum). The essential oil inhibited the growth of S. aureus in its crude concentration (380μg.mL-1), as well as diluted to half (190μg.mL-1) and a quarter strength (95μg.mL-1). It’s likely that such action is due to sesquiterpenes major components, such as bisabolol and bisabolene (10.35%), measured by gas chromatography (GC-MS, GC-FID). Extracts did not exhibit any antimicrobial activity against the microorganisms tested. The native medicinal plants prospective market is an alternative that favours the conservation of biodiversity while generating benefits for the development of sustainable family productive activities within local ecosystems instead of the current inappropriate uses. This strengthens conservation policies of Legal Reserve in rural settlements and is in agreement with public policy on global warming and climate changes.

Can Eucalyptus invade native forest fragments close to commercial stands?

Some Eucalyptus species are widely used as a plantation crop in tropical and subtropical regions. One reason for this is the diversity of end uses, but the main reason is the high level of wood production obtained from commercial plantings. With the advancement of biotechnology it will be possible to expand the geographical area in which eucalypts can be used as commercial plantation crops, especially in regions with current climatic restrictions. Despite the popularity of eucalypts and their increasing range, questions still exist, in both traditional planting areas and in the new regions: Can eucalypts invade areas of native vegetation, causing damage to natural ecosystems biodiversity?The objective of this study it was to assess whether eucalypts can invade native vegetation fragments in proximity to commercial stands, and what factors promote this invasive growth. Thus, three experiments were established in forest fragments located in three different regions of Brazil. Each experiment was composed of 40 plots (1 m(2) each one), 20 plots located at the border between the forest fragment and eucalypts plantation, and 20 plots in the interior of the forest fragments. In each experimental site, the plots were paired by two soil exposure conditions, 10 plots in natural conditions and 10 plots with soil exposure (no plant and no litter). During the rainy season, 2 g of eucalypts seeds were sown in each plot, including Eucalyptus grandis or a hybrid of E. urophylla x E. grandis, the most common commercial eucalypt species planted in the three region. At 15, 30, 45, 90, 180, 270 and 360 days after sowing, we assessed the number of seedlings of eucalypts and the number of seedlings of native species resulting from natural regeneration. Fifteen days after sowing, the greatest number of eucalypts seedlings (37 m(-2)) was observed in the plots with lower luminosity and exposed soil. Also, for native species, it was observed that exposed soil improved natural germination reaching the highest number of 163 seedlings per square meter. Site and soil exposure were the factors that have the greatest influence on seed germination of both eucalypt and native species. However, 270 days after sowing, eucalypt seedlings were not observed at any of the three experimental sites. The result shows the inability of eucalypts to adapt to condition outside of their natural range. However, native species demonstrated their strong capacity for natural regeneration in forest fragments under the same conditions where eucalypts were seeded. (C) 2011 Elsevier B.V. All rights reserved.

Feeding ecology of carnivores (Mammalia, Carnivora) in Atlantic Forest remnants, Southern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Spatial variation in post-dispersal seed removal in an Atlantic forest: Effects of habitat, location and guilds of seed predators

Studies of post-dispersal seed removal in the Neotropics have rarely examined the magnitude of seed removal by different types of granivores. The relative impact of invertebrates, small rodents, and birds on seed removal was investigated in a 2,178 ha Atlantic forest fragment in southeastern Brazil. We used popcorn kernels (Zea mays-Poaceae) to investigate seed removal in a series of selective exclosure treatments in a replicated, paired design experiment that included forest understory, gaps, and forest edge sites. We recorded the vegetation around the experimental seed stations in detail in order to evaluate the influence of microhabitat traits on seed removal. Vertebrate granivores (rodents and birds) were surveyed to determine whether granivore abundance was correlated with seed removal levels. Seed removal varied spatially and in unpredictable ways at the study site. Seed encounter and seed use varied with treatments, but not with habitat type. However, seed removal by invertebrates was negatively correlated with gap-related traits, which suggested an avoidance of large gaps by granivorous ants. The abundance of small mammals was remarkably low, but granivorous birds (tinamous and doves) were abundant at the study site. Birds were the main seed consumers in open treatments, but there was no correlation between local granivorous bird abundance and seed removal. These results emphasize the stochastic spatial pattern of seed removal, and, contrary to previous studies, highlight the importance of birds as seed predators in forest habitats. (c) 2007 Elsevier Masson SAS. All rights reserved.

Priority areas for the conservation of Atlantic forest large mammals

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anurans of a riparian forest in São Carlos, state of São Paulo, Brazil

No presente estudo foi realizado um inventário das espécies de anfíbios anuros que ocorrem em um fragmento de mata ciliar do Córrego do Espraiado, localizado na Universidade Federal de São Carlos (UFSCar), Município de São Carlos, estado de São Paulo, sudeste do Brasil. Durante os meses de março de 2009 a fevereiro de 2010 foram realizadas saídas de campo semanais nas quais foram registradas 13 espécies de anuros. A atividade reprodutiva das espécies de anuros componentes da comunidade estudada mostrou-se sazonal, sendo que houve correlação positiva e significativa entre o número de espécies em atividade reprodutiva e o fotoperíodo. Verificamos que a comunidade estudada mostrou-se mais semelhante a comunidades de anuros de florestas de transição entre Mata Atlântica e Cerrado do que a fragmentos de Cerrado próximos da região.

Atlantic forest fragmentation and genetic diversity of an isolated population of the Blue-manakin, Chiroxiphia caudata (Pipridae), assessed by microsatellite analyses

Habitat fragmentation is predicted to restrict gene flow, which can result in the loss of genetic variation and inbreeding depression. The Brazilian Atlantic forest has experienced extensive loss of habitats since European settlement five centuries ago, and many bird populations and species are vanishing. Genetic variability analysis in fragmented populations could be important in determining their long-term viability and for guiding management plans. Here we analyzed genetic diversity of a small understory bird, the Blue-manakins Chiroxiphia caudata (Pipridae), from an Atlantic forest fragment (112 ha) isolated 73 years ago, and from a 10,000 ha continuous forest tract (control), using orthologous microsatellite loci. Three of the nine loci tested were polymorphic. No statistically significant heterozygote loss was detected for the fragment population. Although genetic diversity, which was estimated by expected heterozygosity and allelic richness, has been lower in the fragment population in relation to the control, it was not statistically significant, suggesting that this 112 ha fragment can be sufficient to maintain a blue-manakin population large enough to avoid stochastic effects, such as inbreeding and/or genetic drift. Alternatively, it is possible that 73 years of isolation did not accumulate sufficient generations for these effects to be detected. However, some alleles have been likely lost, specially the rare ones, what is expected from genetic drift for such a small and isolated population. A high genetic differentiation was detected between populations by comparing both allelic and genotypic distributions. Only future studies in continuous areas are likely to answer if such a structure was caused by the isolation resulted from the forest fragmentation or by natural population structure.

Soil erodibility assessment in a pasture and forest remnant using the inderbitzen device

Brazil has the largest cattle herd in the world with approximately 200 million head. An important feature of the Brazilian cattle industry is that most of its herd is raised on pasture, which constitutes one of the most economical and practical ways to produce and provide food for cattle. However, this production model is mishandled and can lead to soil degradation. Maintaining soil quality is essential for the conservation of natural ecosystems and the areas of production, thus soil quality improves the conditions for biogeochemical cycles. In this context, the objective of this study was to develop a device for testing the Inderbitzen way of assessing soil erodibility in two situations of usage and occupation. Therefore, one area was used as a sample collection occupied by grazing and the other as a forest fragment; both located in the city of Sorocaba in Sao Paulo State, Brazil. Thus, we concluded that the proposed device - the Inderbitzen - proved capable of assessing soil erodibility of the pasture and remnant forest. Accordingly, there was a tendency for a smaller loss of forest soils in the remnant when compared to the degraded pasture. The greatest resistance of the soil erosion in the forest remnant may be associated with the amount of organic matter released by the forest litter in all its diversity, influencing the quality of the structure of aggregates. © 2013 WIT Press.

Euterpe edulis Seedlings in the Understory of Two Forest Fragments

The palm Euterpe edulis is one of the most exploited due the intense illegal extraction, which is very harmful because this species dies right after the cutting process. This study aimed to assess the palms' development as an enrichment plant in a forest fragment belonging to a Preservation Area and the Biosphere Reserve of the Green Belt of Sao Paulo State, in Embu das Artes city. The seeds were obtained from the Instituto Florestal, which follows all the regulations for seeds, in order to get seedlings with a high genetic variation. The seedlings were planted in two successional stages: secondary forest with low trees (SFLT) and secondary forest with medium trees (SFMT). The seedlings survival and growth were periodically assessed and the results were compared by the variance analysis. Both areas presented high rates of survival, which were superior comparing to other similar studies with Euterpe edulis. Despite the successional difference between the areas, the development of the seedlings did not show significant difference on the analysis of variance regarding leaf number, height growth, stem diameter and survival, except for plant height at 60 days after planting, when seedlings planted in SFLT reached higher height (21.38 cm) than when planted in SFMT (19.31 cm).

Soil erodibility assessment in a pasture and forest remnant using the Indrbitzen device

Brazil has the largest cattle herd in the world with approximately 200 million head. An important feature of the Brazilian cattle industry is that most of its herd is raised on pasture, which constitutes one of the most economical and practical ways to produce and provide food for cattle. However, this production model is mishandled and can lead to soil degradation. Maintaining soil quality is essential for the conservation of natural ecosystems and the areas of production, thus soil quality improves the conditions for biogeochemical cycles. In this context, the objective of this study was to develop a device for testing the Inderbitzen way of assessing soil erodibility in two situations of usage and occupation. Therefore, one area was used as a sample collection occupied by grazing and the other as a forest fragment; both located in the city of Sorocaba in Sao Paulo State, Brazil. Thus, we concluded that the proposed device – the Inderbitzen – proved capable of assessing soil erodibility of the pasture and remnant forest. Accordingly, there was a tendency for a smaller loss of forest soils in the remnant when compared to the degraded pasture. The greatest resistance of the soil erosion in the forest remnant may be associated with the amount of organic matter released by the forest litter in all its diversity, influencing the quality of the structure of aggregates. Keywords: erosion, forest remnant, degraded pasture, Inderbitzen test.

A 30-year quantitative comparison of the bird community of a semideciduous forest remnant in the state of Sao Paulo

A 30-year quantitative comparison of the bird community of a semideciduous forest remnant in the state of Sao Paulo. Few studies have evaluated long-term changes in avian abundance in forest remnants. To compare both species richness and abundance of the bird community in a forest fragment located in the municipality of Galia, state of Sao Paulo, southeastern Brazil, we surveyed forest birds using transect counts. We compared our results with a survey conducted 30 years earlier at the same locality and further classified bird species according to their food habits to eventually predict fluctuations of specific abundance. Although species with population declines predominated in the community, all trophic categories had species which increased their abundances. Most species prone to move around remnants decreased in abundance. We suggest that, regarding specific abundances, trophic categories may be equally affected as a result of fragmentation processes and that the forest regeneration of this remnant may have led to the loss of edge species. Species that suffered from abundance loss during this time period may become locally extinct in the near future.

Modeling the age of tropical moist forest fragments in heavily-cleared lowland landscapes of Colombia

Increasingly, large areas of native tropical forests are being transformed into a mosaic of human dominated land uses with scattered mature remnants and secondary forests. In general, at the end of the land clearing process, the landscape will have two forest components: a stable component of surviving mature forests, and a dynamic component of secondary forests of different ages. As the proportion of mature forests continues to decline, secondary forests play an increasing role in the conservation and restoration of biodiversity. This paper aims to predict and explain spatial and temporal patterns in the age of remnant mature and secondary forests in lowland Colombian landscapes. We analyse the age distributions of forest fragments, using detailed temporal land cover data derived from aerial photographs. Ordinal logistic regression analysis was applied to model the spatial dynamics of mature and secondary forest patches. In particular, the effect of soil fertility, accessibility and auto-correlated neighbourhood terms on forest age and time of isolation of remnant patches was assessed. In heavily transformed landscapes, forests account for approximately 8% of the total landscape area, of which three quarters are comprised of secondary forests. Secondary forest growth adjacent to mature forest patches increases mean patch size and core area, and therefore plays an important ecological role in maintaining landscape structure. The regression models show that forest age is positively associated with the amount of neighbouring forest, and negatively associated with the amount of neighbouring secondary vegetation, so the older the forest is the less secondary vegetation there is adjacent to it. Accessibility and soil fertility also have a negative but variable influence on the age of forest remnants. The probability of future clearing if current conditions hold is higher for regenerated than mature forests. The challenge of biodiversity conservation and restoration in dynamic and spatially heterogeneous landscape mosaics composed of mature and secondary forests is discussed. (c) 2004 Elsevier B.V. All rights reserved.