989 resultados para Forest fragment


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Parque das Neblinas (PN) is a 2,800 ha nature reserve contiguous with an Atlantic Forest fragment known as Parque Estadual da Serra do Mar located in the municipality of Bertioga, in the state of São Paulo, Brazil. The area originally contained Eucalyptus trees grown for paper pulp production. The aims of the study were the following: (1) to characterize the diversity of the bird community in PN; (2) to compare bird species observed in PN to species found in the Atlantic Forest; and (3) to list the percentages of species endemic to the Atlantic Forest and present in PN. Quantitative surveys used the point count method. The number of avian species recorded in PN totaled 222, of which 150 (66.4%) were associated with forest environments, 66 (29.3%) with open areas, and 10 (4.3%) with aquatic environments. The quantitative survey recorded 141 species and 2,527 contacts in 120 samples for an average of 21.05 contacts per sample. The general diversity index was H´=3.82. The study identified 15 bird species that actively participated in mixed flocks and 25 species endemic to Atlantic Forest, two of which present some kind of concern relating to conservation. Areas with Eucalyptus trees and a dense understory displayed the greatest bird species diversity, as opposed to areas with less developed or non-existent understories.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Ciência Florestal - FCA

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Melipona scutellaris Latreille has great economic and ecological importance, especially because it is a pollinator of native plant species. Despite the importance of this species, there is little information about the conservation status of their populations. The objective of this study was to assess the diversity in populations of M. scutellaris coming from a Semideciduous Forest Fragment and an Atlantic Forest Fragment in the Northeast Brazil, through geometric morphometric analysis of wings in worker bees. In each area, worker bees were collected from 10 colonies, 10 workers per colony. To assess the diversity on the right wings of worker bees, 15 landmarks were plotted and the measures were used in analysis of variance and multivariate analysis, principal component analysis, discriminant analysis and clustering analysis. There were significant differences in the shape of the wing venation patterns between colonies of two sites (Wilk's lambda = 0.000006; p < 0.000001), which is probably due to the geographical distance between places of origin which impedes the gene flow between them. It indicates that inter and intrapopulation morphometric variability exists (p < 0.000001) in M. scutellaris coming from two different biomes, revealing the existence of diversity in these populations, which is necessary for the conservation of this bee species.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

We investigated the Amblyomma fuscum load on a pullulating wild rodent population and the environmental and biological factors influencing the tick load on the hosts. One hundred and three individuals of Thrichomys laurentius were caught in an Atlantic forest fragment in northeastern Brazil, as part of a longitudinal survey on ticks infesting non-volant small mammals. Ticks (n = 342) were found on 45 individuals and the overall mean intensity of infestation was 7.6 ticks per infested rodent. Ticks were highly aggregated in the host population and the negative binomial distribution model provides a statistically satisfactory fit. The aggregated distribution was influenced by sex and age of the host. The microhabitat preference by T. laurentius probably increases contact opportunities between hosts and aggregated infesting stages of the ticks and represents important clues about the habitat suitability for A. fuscum.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Background: Biological invasions are one of the major causes of biodiversity loss, yet remain rather understudied in tropical environments. The Australian palm tree Archontophoenix cunninghamiana was introduced into Brazil for ornamental purposes, but has become an invasive species in urban and suburban forest patches. The substitution of A. cunninghamiana by the native palm Euterpe edulis has been proposed as a management action. Aims: We aimed to evaluate the regeneration potential of these two palm species in an Atlantic forest remnant in south-eastern Brazil where both species occur. Methods: We compared seedling establishment and seed longevity of both species through seed sowing, and also measured the contribution of A. cunninghamiana to the local seed rain and seed bank. Results: Nearly half of the non-anemochoric diaspores collected from the seed rain belonged to A. cunninghamiana, which represented a high propagule pressure in the community. The distribution of the alien palm seeds in the seed rain correlated with the distribution of nearby young and adult individuals inside the forest. Neither A. cunninghamiana nor E. edulis appeared to have a persistent seed bank in a burial experiment; seedling survival experiments suggested a much better performance for A. cunninghamiana, which had a survival rate of ca. 30% compared with a rate of only 3.5% for E. edulis. Conclusions: The results suggest a higher regeneration capacity for the alien palm over the native species when co-occurring in a forest fragment. Management actions are thus proposed to reduce a potential biological invasion process.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

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 Gália, state of São 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.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

El análisis de los factores que determinan el establecimiento y supervivencia de orquídeas epífitas, incluyen: a) las condiciones microambientales de los bosques que las mantienen, b) preferencias por las características de los hospederos donde crecen, c) limitación en la dispersión de semillas, d) interacciones planta-planta, y e) asociaciones micorrízicas para la germinación y resultan esenciales para el desarrollo de estrategias para la conservación y manejo de este grupo de plantas. Este trabajo ha evaluado la importancia de estos factores en Epidendrum rhopalostele, orquídea epífita del bosque de niebla montano, a través de los análisis de los patrones espaciales de los árboles que la portan y de la propia orquídea, a escala de población, estudios de asociación y métodos moleculares. Estos últimos han consistido en el uso de marcadores AFLP para el análisis de la estructura genética de la orquídea y en la secuenciación-clonación de la región ITS para la identificación de los hongos micorrízicos asociados. El objetivo de esta tesis es, por tanto, una mejor comprensión de los factores que condicionan la presencia de orquídeas epífitas en los remanentes de bosque de niebla montano y una evaluación de las implicaciones para la conservación y mantenimiento de sus hábitats y la permanencia de sus poblaciones. El estudio fue realizado en un fragmento de bosque de niebla montano de sucesión secundaria situado al este de la Cordillera Real, en los Andes del sur de Ecuador, a 2250 m.s.n.m y caracterizado por una pendiente marcada, temperatura media anual de 20.8°C y precipitación anual de 2193 mm. En este fragmento se mapearon, identificaron y caracterizaron todos los árboles presentes con DBH > 1 cm y todos los individuos de Epidendrum rhopalostele. Así mismo se tomaron muestras de hoja para obtener ADN de todas las orquídeas registradas y muestras de raíces de individuos con flor de E. rhopalostele, uno por cada forófito, para el análisis filogenético de micorrizas. Análisis espaciales de patrones de puntos basados en la K de Ripley y la distancia al vecino más cercano fueron usados para los árboles, forófitos y la población de E. rhopalostele. Se observó que la distribución espacial de árboles y forófitos de E. rhopalostele no es aleatoria, ya que se ajusta a un proceso agregado de Poisson. De ahí se infiere una limitación en la dispersión de las semillas en el fragmento estudiado y en el establecimiento de la orquídea. El patrón de distribución de la población de E. rhopalostele en el fragmento muestra un agrupamiento a pequeña escala sugiriendo una preferencia por micro-sitios para el establecimiento de la orquídea con un kernel de dispersión de las semillas estimado de 0.4 m. Las características preferentes del micro-sitio como tipos de árboles (Clusia alata y árboles muertos), tolerancia a la sombra, corteza rugosa, distribución en los dos primeros metros sugieren una tendencia a distribuirse en el sotobosque. La existencia de una segregación espacial entre adultos y juveniles sugiere una competencia por recursos limitados condicionada por la preferencia de micro-sitio. La estructura genética de la población de E. rhopalostele analizada a través de Structure y PCoA evidencia la presencia de dos grupos genéticos coexistiendo en el fragmento y en los mismos forófitos, posiblemente por eventos de hibridización entre especies de Epidendrum simpátricas. Los resultados del análisis de autocorrelación espacial efectuados en GenAlex confirman una estructura genético-espacial a pequeña escala que es compatible con un mecanismo de dispersión de semillas a corta distancia ocasionada por gravedad o pequeñas escorrentías, frente a la dispersión a larga distancia promovida por el viento generalmente atribuida a las orquídeas. Para la identificación de los micobiontes se amplificó la región ITS1-5.8S-ITS2, y 47 secuencias fueron usadas para el análisis filogenético basado en neighborjoining, análisis bayesiano y máximum-likelihood que determinó que Epidendrum rhopalostele establece asociaciones micorrízicas con al menos dos especies diferentes de Tulasnella. Se registraron plantas que estaban asociadas con los dos clados de hongos encontrados, sugiriendo ausencia de limitación en la distribución del hongo. Con relación a las implicaciones para la conservación in situ resultado de este trabajo se recomienda la preservación de todo el fragmento de bosque así como de las interacciones existentes (polinizadores, micorrizas) a fin de conservar la diversidad genética de esta orquídea epífita. Si fuere necesaria una reintroducción se deben contemplar distancias entre los individuos en cada forófito dentro de un rango de 0.4 m. Para promover el reclutamiento y regeneración de E. rhopalostele, se recomienda que los forófitos correspondan preferentemente a árboles muertos o caídos y a especies, como Clusia alata, que posean además corteza rugosa, sean tolerantes a la sombra, y en el área del sotobosque con menor luminosidad. Además es conveniente que las orquídeas en su distribución vertical estén ubicadas en los primeros metros. En conclusión, la limitación en la dispersión, las características del micro-sitio, las interacciones intraespecíficas y con especies congenéricas simpátricas y las preferencias micorrízicas condicionan la presencia de esta orquídea epífita en este tipo de bosque. ABSTRACT The analysis of factors that determine the establishment and survival of epiphytic depends on factors such as a) microenvironmental conditions of forest, b) preference for host characteristics where orchids grow, c) seed dispersal limitation, d) plant-plant interaction, e) priority mycorrhizal associations for germination, are essential for the development of strategies for management and conservation. This work evaluated the importance of these factors in Epidendrum rhopalostele, an epiphytic orchid of montane cloud forest through the analysis of spatial patterns of host trees and the orchid, in a more specific scale, with association studies and molecular methods, including AFLPs for orchid population genetic structure and the sequencing of the ITS region for associated mycorrhizal fungi. The aim of this thesis is to understand the factors that condition the presence of epiphytic orchids in the remnants of montane cloud forest and to assess the implications for the conservation and preservation of their habitats and the persistence of the orchid populations. The study was carried out in a fragment of montane cloud forest of secondary succession on the eastern slope of Cordillera Real in the Andes of southern Ecuador, located at 2250 m a.s.l. characterized by a steep slope, mean annual temperature of 20.8°C and annual precipitation of 2193 mm. All trees with DBH > 1 cm were mapped, characterized and identified. All E. rhopalostele individuals present were counted, marked, characterized and mapped. Leaf samples of all orchid individuals were collected for DNA analysis. Root samples of flowering E. rhopalostele individuals were collected for phylogenetic analysis of mycorrhizae, one per phorophyte. Spatial point pattern analysis based on Ripley`s K function and nearest neighbor function was used for trees, phorophytes and orchid population. We observed that spatial distribution of trees and phorophytes is not random, as it adjusts to a Poisson cluster process. This suggests a limitation for seed dispersal in the study fragment that is affecting orchid establishment. Furthermore, the small-scale spatial pattern of E. rhopalostele evidences a clustering that suggests a microsite preference for orchid establishment with a dispersal kernel of 0.4 m. Microsite features such as types of trees (dead trees or Clusia alata), shade tolerance trees, rough bark, distribution in the first meters suggest a tendency to prefer the understory for their establishment. Regarding plant-plant interaction a spatial segregation between adults and juveniles was present suggesting competition for limited resources conditioned for a microsite preference. Analysis of genetic structure of E. rhopalostele population through Structure and PCoA shows two genetic groups coexisting in this fragment and in the same phorophyte, possibly as a result of hybridization between sympatric species of Epidendrum. Our results of spatial autocorrelation analysis develop in GenAlex confirm a small-scale spatial-genetic structure within the genetic groups that is compatible with a short-distance dispersal mechanism caused by gravity or water run-off, instead of the long-distance seed dispersal promoted by wind generally attributed to orchids. For mycobionts identification ITS1-5.8S-ITS2 rDNA region was amplified. Phylogenetic analysis was performed with neighborjoining, Bayesian likelihood and maximum-likelihood for 47 sequences yielded two Tulasnella clades. This orchid establishes mycorrhizal associations with at least two different Tulasnella species. In some cases both fungi clades were present in same root, suggesting no limitation in fungal distribution. Concerning the implications for in situ conservation resulting from this work, the preservation of all forest fragment and their interactions (pollinators, mycorrhiza) is recommended to conserve the genetic diversity of this species. If a reintroduction were necessary, distances between individuals in each phorophyte within a range of 0.4 m, are recommended. To promote recruitment and regeneration of E. rhopalostele it is recommended that phorophytes correspond to dead or fallen trees or species, such as Clusia alata. Trees that have rough bark and are shade tolerant are also recommended. Furthermore, regarding vertical distribution, it is also convenient that orchids are located in the first meter (in understory, area with less light). In conclusion, limitation on seed dispersal, microsite characteristics, plant-plant interactions or interaction with cogeneric sympatric species and mycorrhizal preferences conditioned the presence of this epiphytic orchid in this fragment forest.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

A Mata Atlântica é considerada um dos biomas mais importantes do mundo devido à sua alta biodiversidade e funções ecossistêmicas. Entretanto, encontra-se fragmentada em porções de pequenas dimensões esparsas em uma matriz predominantemente agrícola, composta principalmente por extensas pastagens e monoculturas. Desse modo, os sistemas agroflorestais por apresentarem uma estrutura diferenciada dos monocultivos e similar às condições naturais, podem ser utilizados como uma alternativa para o manejo e a conservação da biodiversidade nos remanescentes florestais. A fragmentação provoca modificações no ambiente que irão refletir na perda e no deslocamento da biodiversidade, estando os insetos entre os grupos mais afetados. Uma das formas de se avaliar o estado de conservação dos fragmentos e o impacto antrópico nos sistemas vegetacionais, é estudar a presença e distribuição de organismos bioindicadores. Dentre esses, os insetos ocupam posição de destaque. Os insetos da família Scarabaeidae e da subfamília Scolytinae são bons indicadores de distúrbios, pois são muito sensíveis ás mudanças ambientais. Neste trabalho hipotetisou-se que a presença desses insetos está relacionada com a estrutura da vegetação e as condições de vida proporcionadas pelas diferentes formas de uso-da-terra. O objetivo desta pesquisa foi avaliar a diversidade de espécies, o padrão de abundância e a similaridade entre as populações de coleópteros (Scarabaeidae e Scolytinae) em diferentes sistemas vegetacionais de diferentes estruturas: i) Fragmento de floresta estacional semidecidual dividido em três áreas: beira do rio, centro e borda; ii) Sistema Agroflorestal (SAF) (interface entre o fragmento e o pasto); iii) Pasto composto de Brachiaria decumbens (L.); iv) Monocultivo de café (Coffea arábica L.); v) Monocultivo de seringueira (Hevea brasiliensis Müell. Arg.); vi) SAF de café e seringueira - todos situados numa região de domínio anterior de floresta estacional semidecidual em Piracicaba-SP. Os sistemas foram caracterizados quanto à sua estrutura e condições micrometeorológicas. Os insetos foram coletados mensalmente entre agosto/2013 e julho/2014 utilizando-se dois tipos de armadilhas: Pitfall e etanol modelo ESALQ-84. Foram coletados 1.047 espécimes distribuídos em 21 espécies da família Scarabaeidae e 1.833 indivíduos de 38 espécies da subfamília Scolytinae. A maior quantidade de espécies de Scarabaeidae foi encontrada na borda do fragmento florestal, enquanto que a maior abundância ocorreu no fragmento florestal perto do rio. A subfamília Scolytinae apresentou a maior riqueza de espécies no sistema agroflorestal misto (borda) e a maior abundância no sistema agroflorestal café-seringueira. A abundância e riqueza de espécies da família Scarabaeidae foram correlacionadas positivamente com a temperatura do ar, temperatura e umidade do solo e a precipitação. Por outro lado, a abundância e a riqueza de espécies da subfamília Scolytinae apresentaram correlação negativa com a temperatura do ar e a temperatura e umidade do solo. Ambos os grupos de insetos apresentaram a maior abundância e riqueza de espécies nas áreas com estrutura vegetacional mais complexa, sendo influenciadas pelas condições microclimáticas dentro de cada local.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

After providing background on Dendrolagus species in Australia, two consecutive surveys of Brisbane's residents are used to assess public knowledge of tree-kangaroos and the stated degree of support for their conservation in Australia. The responses of participants in Survey I are based on their pre-survey knowledge of wildlife. The same set of participants completed Survey II after being provided with additional information on all the wildlife species mentioned in Survey I. Changes in the attitudes of respondents and their degree of support for the protection and conservation of Australia's tree-kangaroos are measured, including changes in their contingent valuations and stated willingness to provide financial support for such conservation. Reasons for wanting to protect tree-kangaroos are specified and analysed. Furthermore, changes that occur in the relative importance of these reasons with increased knowledge are also examined. Support for the conservation of tree-kangaroos is found to rise with the additional knowledge supplied about all species and is compared with variations in support for protection of other mammals. Support for the conservation of Australia's less well known tropical mammals is found to increase relative to better known mammals (icons) present in temperate areas, such as koalas and red kangaroos. Possible implications of the results for government conservation policies in Australia are examined.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

To design strategies for the conservation and use of genetic resources of tree species such as jaboticaba tree, it is essential to make the characterization. In southwestern Paraná region, there are several forest fragments containing native jaboticaba tree (Plinia cauliflora), whose materials have broad potential for commercial orchards or breeding programs. As is the potential genetic diversity of a population to produce different genotypes, it would be able to start in such a characterization one of these fragments. The aim was to characterize fruits of jaboticaba tree (P. caulifora) of forest fragment kept in Clevelândia - PR for the presence of phenotypic variability, seeking to identify those superiors named for future selection as farming or male parent, as well as estimate genetic divergence between them, as a complementary tool for this purpose. Also, verify the regeneration and spatial distribution of the species. For the study was defined portion of a hectare (10.000 m²), with all individuals identified, mapped, with local coordinate system, and measured height and diameter. Fruits were characterized by sensory and biochemical characteristics in two years, 70 genotypes at 2013 and 56 at 2014, and of these 33 genotypes in both years. As a pre-selection criteria was adopted the choice of 20% of the genotypes that showed the highest frequency of superiority in the evaluated characteristics of the fruit. Genetic divergence among 33 genotypes per year was analyzed. The distribution pattern and spatial association was evaluated by Ripley's K function. It was classified for the first time the following ontogenetic stages of jaboticaba tree, by plant height, seedling (from 0.01 to 0.99 m), juvenile (1.0 to 4.99 m), immature (> 5.0 m, non-reproductive), adult (reproductive). It was also have been describe for the first time the naturally occurring juxtaposed seedlings, indicating polyembryony. The number of regenerating identified in the population (seedlings: n = 2163; juveniles: n = 330; immature: n = 59) was much larger than the number of adults (n = 132). The species showed reverse J-shaped size structure standard, with high concentration of regenerating. The regeneration distribution occurs in aggregate pattern and there is seedling-adult dependence, due seed dispersal and seedling emergence closest to mothers. The jaboticaba tree regeneration is sufficient to maintain the species for long term in this population, which should serve as reference to regeneration success for other studies of this important fruiting species from Ombrofile Mixed Forests. Has been pre-selected the jaboticaba trees 7, 42, 43, 47, 54, 91, 97, 104, 105, 118, 134, 153, 154, 157, 163, 169, 177, 186, 212, J7-01 and J7- 02, and 16 and 194 the ones that can now be selected by the superior characteristics of both cycles. It was recommended to carry out hybridization between genotypes 79 and 119, and 96 to 148. The quality of fruit analyzed showed potential for use as a dual purpose serving both in natura market or processing.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Over time, humanity began to realize the negative impact that the modern world has caused to the environment. The Atlantic Forest is one of the richest biomes in biodiversity, covering more than 60% of all species on the planet. This biome covered about 15% of the Brazilian territory, leaving currently only 7% of its fully fragmented forest remnants. This was the biome that suffered most from modernization and strong anthropogenic pressures in Brazil. For the account of environmental degradation, in the second half of the nineteenth century there was a shift in thinking, giving greater emphasis on conservation of some natural landscapes, with the intention of removing the man still preserved nature. Based on American models of conservation there were created the Nature Conservation Units. This study aimed to analyze the environmental quality of the State Park Vitório Piassa, a Conservation Unit located in the city of Pato Branco - PR. The environmental quality was measured by use of bio-indicators and some environmental pressures that the Park has suffered over the years also were identified. Beetles of the familiy Scarabaeinae (Coleoptera: Scarabaeidae) were used as the bioindicators. To compare the most conserved areas and the most degraded areas of the Park, three specific sites were defined within the Atlantic Forest fragment, these insects were captured with pitfall traps and identified as to their species and genera. There were two collections in February and March 2015, which resulted in 945 individuals in 22 species and nine different genus. Then the population of beetles in each area were classified based on ecological measures such as species richness, abundance of individuals of each species through diversity index (Shannon and Simpson) to identify the differences between the sampled groups and equitability (Pielou) to measure the distribution of the total abundance of the species in each area. To meet the objective of identifying the environmental pressures that occur in PEVP, evidence were collected through photographs, watching the field, aerial images and conversations with the resident population in the park. Similarly, if made relevant to build on the project running by the municipality for the construction of infrastructure for public viewing. These data served as subsidies to confront the current situation of the park and the current Brazilian legislation for UC's of full protection, highlighting the existing socio-environmental conflicts in the park, involving political issues and the proximity of the Conservation Unit with the urban area of the city.