123 resultados para Tree Similarity
em Scielo Saúde Pública - SP
Resumo:
A large-scale inventory of trees > 10cm DBH was conducted in the upland "terra firme" rain forest of the Distrito Agropecuário da SUFRAMA (Manaus Free Zone Authority Agricultural District) approximately 65Km north of the city of Manaus (AM), Srasil. Thegeneral appearance and structure of the forest is described together with local topography and soil texture. Thepreliminary results of the Inventory provide a minimum estimate of 698 tree species in 53 families in the 40Km radius sampled, including 17 undescribed species. Themost numerically abundant families, Lecythidaceae, Leguminosae, 5apotaceae and Burseraceae as also among the most species rich families. One aspect of this diverse assemblage is the proliferation of species within certain genera, Including 26 genera In 17 families with 6 or more species or morphospecies. Most species have very low abundances of less than 1 tree per hectare. While more abundant species do exist at densities ranging up to a mean of 12 trees per ha, many have clumped distributions leading to great variation in local species abundance. The degree of similarity between hectare samples based int the Coefficient of Community similarity Index varies widely over different sample hectares for five ecologically different families. Soil texture apparently plays a significant role In determining species composition in the different one hectare plots examined while results for other variable were less consistent. Greater differences in similarity indices are found for comparisons with a one hectare sample within the same formation approximately 40Km to the south. It is concluded that homogeneity of tree community composition within this single large and diverse yet continuous upland forest formation can not be assumed.
Resumo:
The high tree diversity and vast extent of Amazonian forests challenge our understanding of how tree species abundance and composition varies across this region. Information about these parameters, usually obtained from tree inventories plots, is essential for revealing patterns of tree diversity. Numerous tree inventories plots have been established in Amazonia, yet, tree species composition and diversity of white-sand and terra-firme forests of the upper Rio Negro still remain poorly understood. Here, we present data from eight new one-hectare tree inventories plots established in the upper Rio Negro; four of which were located in white-sand forests and four in terra-firme forests. Overall, we registered 4703 trees > 10 cm of diameter at breast height. These trees belong to 49 families, 215 genera, and 603 species. We found that tree communities of terra-firme and white-sand forests in the upper Rio Negro significantly differ from each other in their species composition. Tree communities of white-sand forests show a higher floristic similarity and lower diversity than those of terra-firme forests. We argue that mechanisms driving differences between tree communities of white-sand and terra-firme forests are related to habitat size, which ultimately influences large-scale and long-term evolutionary processes.
Resumo:
Spondias mombin L. is a fruit tree from the American continent from the Anacardiaceae family. In Brazil it is common in different vegetation types but is more frequent in the Atlantic and Amazonian rainforests. It is economically important because of its fruits, which are widely consumed raw or processed as fruit jellies, juices and ice creams. The leaves have great importance in the pharmaceutical industry because of their antibacterial properties. In the state of Pernambuco, cajá tree is widely distributed in the Zona da Mata region and less frequently in the Agreste and Sertão areas. In this work diversity and genetic structure were studied in four populations of cajá tree from Pernambuco's Zona da Mata, Northeast Brazil, using isozymes polymorphism analyses from electrophoreses. The result showed 100% of polymorphism (P) for nine alleles and the average of alleles per locus s was 2.4. The expected heterozygosity
ranged from 0.530 to 0.574 and the observed heterozygosity
, from 0.572 to 0.735. It was not observed inbreeding and the average F IT was -0.175, whereas within population inbreeding (f) varied from -0.08 to- 0.37. The genetic divergence among the populations (F ST) ranged from 0.006 to 0.028 and the average was 0.026. The average of estimated gene flow (Nm) was high (5.27). The CG-IPA population, corresponding to the germplasm collection of IPA, showed more than 96% of genetic similarity with other populations; therefore, it is a good representative of the existent genetic diversity in the Zona da Mata region.
Resumo:
The horizontal and vertical tree community structure in a lowland Atlantic Rain Forest was investigated through a phytosociological survey in two 0.99 ha plots in the Intervales State Park, São Paulo State. All trees > 5 cm diameter at breast height were recorded. 3,078 individuals belonging to 172 species were identified and recorded. The Shannon diversity index was H' = 3.85 nat.ind.-1. The Myrtaceae family showed the greatest floristic richness (38 species) and the highest density (745 individuals) in the stand. Euterpe edulis Mart. had the highest importance value (33.98%) accounting for 21.8% of all individuals recorded. The quantitative similarity index was higher than the qualitative index, showing little structural variation between plots. However, the large number of uncommon species resulted in pronounced floristic differences. A detrended correspondence analysis (DCA) generated three arbitrary vertical strata. Stratum A (> 26 m), where Sloanea guianensis (Aubl.) Benth. and Virola bicuhyba (Schott. ex A.DC.) Warb. were predominant showed the lowest density. Stratum B (8 m < h < 26 m) had the greatest richness and diversity, and stratum C (< 8 m) showed the highest density. Euterpe edulis, Guapira opposita (Vell.) Reitz, Garcinia gardneriana (Planch. & Triana) Zappi, and Eugenia mosenii (Kausel) Sobral were abundant in strata B and C. The occurrence of strata in tropical forests is discussed and we recommend the use of DCA for others studies of the vertical distribution of tropical forest tree communities.
Resumo:
The aim of this study is to investigate the floristic composition of an Atlantic rain forest fragment located in Cananéia, São Paulo, Brazil, and to contribute to the knowledge on Atlantic forest through the comparative analysis of this and other floristic surveys both on the southern and southeastern Brazil, in different soil and relief types. We surveyed 215 species in 132 genera and 51 families. Classification and ordination analysis were applied to a binary matrix in order to analyze the similarity among 24 surveys, including the present one, of Atlantic forest from the south and southeast coast of Brazil. Higher floristic similarity was observed among this area and the ones where there was marine influence and more rugged relief. The surveys in areas with greater marine influence (sandy soil) were separated from those in other conditions, possibly indicating a species replacement gradient from the steep slopes towards the lowland and were probably related to different edaphic conditions. A latitudinal gradient was found among the surveys apparently confirming a continuous species replacement along the Atlantic forest, related to a restricted distribution of the species. This suggests that it is essential to preserve areas from the whole Atlantic coast. Atlantic forest distribution is quite complex and its composition cannot be adequately represented by small localized areas.
Resumo:
We describe the floristic composition of the tree-shrub vegetation in 10 areas of rocky outcrop cerrado in Goiás State, Brazil. Ten 20×50m plots (totaling 1ha) were established and all of the individuals with diameters at 30cm above soil level (DB30) ³5cm were included in the sampling. Comparative analyses of the flora were realized using similarity indices (Sørensen and Czekanowski), classification analysis (TWINSPAN), and the Mantel test. A total of 13,041 tree-shrub individuals were sampled, distributed among 219 species, 129 genera and 55 families. Fabaceae was the most well-represented family, followed by Myrtaceae, Melastomataceae, Vochysiaceae, Malphigiaceae, and Rubiaceae. Fully 42.3% of the comparisons evaluated by the Sørensen index were >0.50, while all the values were <0.50 for the Czekanowski index, with the exception of Jaraguá and Mara Rosa areas. The TWINSPAN classification generated four divisions and, in general, only the differences in the size of the population were responsible for the groupings. The Mantel test indicated that there was no relationship between floristic similarity and the distances between the areas (r=0.32, P=0.05). It therefore appears that the areas of rocky outcrop cerrado in Goiás State are relatively floristically homogeneous and that they are principally distinguished by the differences in the sizes of the populations of their dominant species, and the presence of exclusive species in certain areas.
Resumo:
Polyembryonic seeds are characterized by the development of over one embryo in the same seed, which can be zygotic and nucellar. The objective of this work was to identify the genetic origin, whether zygotic or nucellar, of seedlings of polyembryonic seeds of 'Ubá' mango tree using ISSR markers, and relating them with the vigor of the seedlings. Thus, mangos were harvested in Visconde do Rio Branco (accession 102) and Ubá (accessions 112, 138, 152 and 159), whose seeds were germinated in plastic trays filled with washed sand. Fifty days after sowing, seedlings from five seeds of each one of the accessions 102, 112, 138, 159 and from 10 seeds of the accession 152, were analyzed. These sseedlings were characterized and evaluated for plant height, stem circumference and mass of fresh aerial part and the most vigorous seedling was the one displaying at least two of these traits higher than the other seedlings from seed. Leaves were collected for genomic DNA extraction, which was amplified using seven ISSR primers previously selected based on the amplification profile and considering the number and resolution of fragments. Zygotic seedlings were found in 18 seeds, which were the most vigorous in six seeds. The results evidenced the existence of genetic variability in orchards using seedlings grown from seeds, because the farmer usually uses the most vigorous ones, assuming that this is of nucellar origin. These results also indicate that the most vigorous seedling are not always nucellar, inasmuch as of 20% of the total seeds evaluated, the zygotic seedling was the most vigorous.
Resumo:
Light and soil water availability may limit carbon uptake of trees in tropical rainforests. The objective of this work was to determine how photosynthetic traits of juvenile trees respond to variations in rainfall seasonality, leaf nutrient content, and opening of the forest canopy. The correlation between leaf nutrient content and annual growth rate of saplings was also assessed. In a terra firme rainforest of the central Amazon, leaf nutrient content and gas exchange parameters were measured in five sapling tree species in the dry and rainy season of 2008. Sapling growth was measured in 2008 and 2009. Rainfall seasonality led to variations in soil water content, but it did not affect leaf gas exchange parameters. Subtle changes in the canopy opening affected CO2 saturated photosynthesis (A pot, p = 0.04). Although A pot was affected by leaf nutrient content (as follows: P > Mg > Ca > N > K), the relative growth rate of saplings correlated solely with leaf P content (r = 0.52, p = 0.003). At present, reduction in soil water content during the dry season does not seem to be strong enough to cause any effect on photosynthesis of saplings in central Amazonia. This study shows that leaf P content is positively correlated with sapling growth in the central Amazon. Therefore, the positive effect of atmospheric CO2 fertilization on long-term tree growth will depend on the ability of trees to absorb additional amount of P
Resumo:
The C. cerifera palm tree (carnaúba) is widely distributed in the Northeastem Brazil, including the State of Piauí. This investigation revealed that R. nasutus is the ortly triatomine species captured on that palm tree, in five different localities. 78% of palm trees were infested with triatomines, and 4.0% were infected with flagellates morphologically and biologically indistinguishable from Trypanosoma cruzi. Birds, rodents and marsupials were found as major blood meai sources for R. nasutus.
Resumo:
The authors report a massive attack by Pseudomyrmex ants on a human who touched a Triplaria - novice tree (Triplaris spp). The ants naturally live in these trees and their stings cause intense pain and discrete to moderate local inflammation. The problem is common in some Brazilian regions and can be prevented by identifying the trees.
Resumo:
IntroductionDetermining the genetic similarities among Trypanosoma cruzi populations isolated from different hosts and vectors is very important to clarify the epidemiology of Chagas disease.MethodsAn epidemiological study was conducted in a Brazilian endemic area for Chagas disease, including 76 chronic chagasic individuals (96.1% with an indeterminate form; 46.1% with positive hemoculture).ResultsT. cruzi I (TcI) was isolated from one child and TcII was found in the remaining (97.1%) subjects. Low-stringency single-specific-primer-polymerase chain reaction (LSSP-PCR) showed high heterogeneity among TcII populations (46% of shared bands); however, high similarities (80-100%) among pairs of mothers/children, siblings, or cousins were detected.ConclusionsLSSP-PCR showed potential for identifying similar parasite populations among individuals with close kinship in epidemiological studies of Chagas disease.
Resumo:
Two canopies of a widely distributed Amazonian tree species, Goupia glabra Aubl. (Celastraceae, height 38 and 45m) were fogged several times with 1% natural pyrethrum during the rainy and dry seasons (1991-1994) in the Adolpho Ducke Forest Reserve near Manaus/Brazil. Between 50 and 158 ind./m2 of arthropods were obtained per tree and fogging event. Hymenoptera, mostly Formicidae, and Diptcra dominated. A total of 95 ant species occurred on a single tree. Most ants were permanently foraging in the canopy and their recolonization after fogging seems to follow stochastic pathways. Data indicated an interaction between - 1) predating Formicidae and gall building Cecidomyiidae and - 2) Cecidomyiidae and the parasitic Hymenoptera.
Resumo:
The aim of this study was to test the hypothesis that the monodominant non-pioneer Peltogyne gracilipes, typically does not suffer density-dependent herbivory (Janzen-Connell model). Two components of intraspecific variation in leaf herbivory were measured: 1) the variation between individuals in the population at the same time and 2) the temporal variation in rates of damage to each individual. The study was carried out on Maracá Island, Roraima, Brazil in three plots (50 m χ 50 m) in each of three forest types: Peltogyne-rich forest (PRF), Peltogyne-poor forest (PPF), and forest without Peltogyne (FWP). Two other non-pioneer species (Ecclinusa guianensis and Pradosia surinamensis) were chosen for comparison because they were fairly abundant and their seedlings could be readily identified. The values of leaf area removed by herbivores of trees and seedlings of the three study species were in the range reported for other tropical tree species (2-16%, standing damage). There were no differences within species between forests. However, there was a significant difference among species but this was not correlated with seedling density. Peltogyne seedlings showed no evidence of density-dependent herbivory as predicted by the Janzen-Connell model despite the fact that adult trees were observed to suffer a mass defoliation in April 1992. This result suggests that Peltogyne may be dominant partly due to escape from herbivory in the early stages of its life although it may suffer occasional mass defoliation as an adult.
Resumo:
This study investigates patterns of forest structure and tree species diversity in an anthropogenic palm grove and undisturbed areas at the seasonally-dry Pinkaití research station, in the Kayapó Indigenous Area. This site, managed by the Conservation International do Brasil, is the most southeastern site floristically surveyed in the Amazon until now. The secondary and a nearby undisturbed forest were sampled in a group of 52 floristic plots of 0.0625-ha (25x25-m) where all trees with DBH > 10 cm were measured and identified. The analyses were complemented with other two floristic plots of 1-ha (10x1000-m). The present study has shown that the Pinkaití, like other seasonally-dry forests, have great heterogeneity in forest structure and composition, associated with biotic characteristics of the most important tree species, natural disturbance and history of land-use. The palm grove, moderately dominated by the arborescent palm Attalea maripa (Aubl.) Mart., presented high tree species diversity and was floristically similar to undisturbed forests at the study site. It is discussed the importance of large arborescent palms for the seasonally-dry Amazon forests regeneration.
Resumo:
A multilocus mixed-mating model was used to evaluate the mating system of a population of Couratari multiflora, an emergent tree species found in low densities (1 individual/10 ha) in lowland forests of central Amazonia. We surveyed and observed phenologically 41 trees in an area of 400 ha. From these, only four mother trees were analyzed here because few of them set fruits, which also suffered high predation. No difference was observed between the population multilocus outcrossing rate (t mp = 0.953 ± 0.040) and the average single locus rate (t sp = 0.968 ± 0.132). The four mother trees were highly outcrossed (t m ~ 1). Two out of five loci showed departures from the Hardy-Weinberg Equilibrium (HWE) expectations, and the same results occurred with the mixed-mating model. Besides the low number of trees analyzed, the proportion of loci in HWE suggests random mating in the population. However, the pollen pool was heterogeneous among families, probably due to both the small sample number and the flowering of trees at different times of the flowering season. Reproductive phenology of the population and the results presented here suggest, at least for part of the population, a long-distance pollen movement, around 1,000 m.