962 resultados para Fennoscandian forests
Resumo:
Social wasp diversity in Semideciduous Seasonal Forests of the northeast of Sao Paulo State is poorly known, causing a lack of information on the diversity of these wasps from these areas which have been degraded. The objective of this work was to evaluate the social wasp (Vespidae, Polistinae) diversity in a Semideciduous Seasonal Forest of the northeast of Sao Paulo State and to compare three different kinds of sampling methodology. Surveys were conducted from August 2005 to September 2006 in the interior, edge and matrix of a Semideciduous Seasonal Forest fragment in Patrocinio Paulista city, Sao Paulo State. Three methodologies were used: 1. Active collection in flowers, 2. Searching for nests, 3. Active collection with attractive liquid. Thirty species of social wasps were collected in the fragment, but the diversity was highest in the edge. Active collection with attractive liquid was the most efficient methodology. Despite the high levels of deforestation, forest fragments in Sao Paulo State have a high diversity of social wasps, reinforcing the importance of their preservation.
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The advance of agricultural frontier may cause the Cerrado (Brazilian savanna) to disappear before 2030. This work focuses on measuring the impact of pasture implantation on a cerrado`s termite fauna. Termites were sampled in a cerrado sensu stricto and a pasture, originally cerrado. All species were classified as their feeder group, accumulation curves were made and Shannon-Wiener indexes and beta diversity were calculated for both areas. Cerrado was richer than pasture and species composition differed considerably, leading beta diversity to a high value. The humivorous was the most representative species, followed by grass/litter feeders, xylophagous and, less representative, the intermediates. There were more xylophagous and intermediates species on cerrado than in pasture; the grass/litter feeders were more abundant in pasture, but didn`t differed in number or species; and humivorous didn`t differed neither in richness nor in abundance. This work shows that the simplification of the habitat is indeed causing the extinction of populations that depend on some specifics resource.
Resumo:
1. Chrysophtharta bimaculata is a native chrysomelid species that can cause chronic defoliation of plantation and regrowth Eucalyptus forests in Tasmania, Australia. Knowledge of the dispersion pattern of C. bimaculata was needed in order to assess the efficiency of an integrated pest management (IPM) programme currently used for its control. 2. Using data from yellow flight traps, local populations of C. bimaculata adults were monitored over a season at spatial scales relevant to commercial forestry: within a 50-ha operational management unit (a forestry 'coupe') and between coupes. In addition, oviposition was monitored over a season at a subset of the between-coupe sites. 3. Dispersion indices (Taylor's Power Law and Iwao's Mean Crowding regression method) demonstrated that C. bimaculata adults were spatially aggregated within and between coupes, although the number of egg-batches laid at the between-coupe scale was uniform. Spatial autocorrelation analysis showed that trap-catches at the within-coupe level were similar (positively autocorrelated) to a radius distance of approximately 110 m, and then dissimilar (negatively autocorrelated) at approximately 250 m. At the between-coupe scale, no repeatable spatial autocorrelation patterns were observed. 4. For any individual site, rapid changes in beetle density were observed to be associated with loosely aggregated flights of beetles into and out of that site. Peak adult catches (> the weekly mean plus standard deviation trap-catch) for a site occurred for a period of 2.0 +/- 0.22 weeks at a time (n = 37), with normally only one or two peaks per site per season. Peak oviposition events for a site occurred on average 1.4 +/- 0.11 times per season and lasted 1.5 +/- 0.12 weeks. 5. Analysis of an extensive data set (n = 417) demonstrated that adult abundance at a site was positively correlated with egg density, but negatively correlated with tree damage (caused by conspecifics) and the presence of conspecific larvae. There was no relationship between adult abundance and a visual estimate of the amount of young foliage on trees. 6. Adults of C. bimaculata are show n to occur in relatively small, mobile aggregations. This means that pest surveys must be both regular (less than 2 weeks apart) and intensive (with sampling points no more than 150 m apart) if beetle populations are to be monitored with confidence. Further refinement of the current IPM strategy must recognize the problems posed by this temporal and spatial patchiness, particularly with regard to the use of biological insecticides, such as Bacillus thuringiensis, for which only a very short operational window exists.
Resumo:
Alouatta guariba clamitans (brown howler monkey) is an endemic primate from the southeastern Brazil tropical forests, classified as near threatened by the IUCN Red List 2007. The genus Aloualta is one of the most difficult New World monkeys to breed and rear in captivity. In this study we examined the macroscopic and histological aspects of the female genital tract of wild brown howler monkeys to provide baseline information for future reproduction research. The anatomical relationship between the vagina, uterus, broad ligament, oviducts and ovaries are those of a typical primate reproductive tract. The fundic portion of the uterus is globoid, the cervix is well developed, which confers to the uterus an elongated shape, and the vagina is a long flattened channel. Histological analysis conducted in females in the follicular phase revealed large quantities of interstitial luteinized tissue in the ovaries, a stratified nonkeratinized vaginal epithelium, lack of glands in the vaginal mucosa and simple tubular endometrial glands. The observed anatomical features should be considered in the adaptation and application of assisted reproductive techniques aimed at improving captive reproduction for species conservation. Am. J. Primatol. 71:145-152, 2009. (C) 2008 Wiley-Liss, Inc.
Resumo:
Sloths (Bradypus sp.) are extremely sensitive animals that suffer with the destruction and fragmentation of forests. They present a low population growth rate and need to be further studied for the preservation of the specie. Thus, the aim of this study was to establish an efficient semen collection protocol as well as characterize sperm concentration, motility and morphology in order to contribute with information about the reproductive traits of this specie, which has never been described in the literature before. For that, nine Bradypus tridactylus males were captured during the wet season and six during the dry season, in Manaus (AM), located in the north region of Brazil, semen was collected by electroejaculation with shocks given in sequences of progressive intensities (minimum 20 mA and maximum 60 mA). All animals ejaculated small volumes of semen and in some of them, the volume ejaculated was not enough for a complete spermiogram. Physical characteristics observed on the collections of the wet season were different from those seen in the specimen collected in the dry season. Motility an vigor was very low and did not show forward progression, only oscillatory movement. After Spermac stain, spermatozoa presented a wide variety of defects; however, the differences in morphology were not significant between seasons. The morphology assessed by scanning electron microscopy shows that the head in both groups could be elongated, short or could have a base narrower than the apex and the midpiece narrowed abruptly, forming a nip in its transition to the tail. Although further studies are necessary to verify our preliminary findings concerning seasonal variation in sperm quality, these results demonstrate that semen can be safely collected from sloths by electroejaculation and provide the first reports of semen characteristics in this species. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
The collection of spatial information to quantify changes to the state and condition of the environment is a fundamental component of conservation or sustainable utilization of tropical and subtropical forests, Age is an important structural attribute of old-growth forests influencing biological diversity in Australia eucalypt forests. Aerial photograph interpretation has traditionally been used for mapping the age and structure of forest stands. However this method is subjective and is not able to accurately capture fine to landscape scale variation necessary for ecological studies. Identification and mapping of fine to landscape scale vegetative structural attributes will allow the compilation of information associated with Montreal Process indicators lb and ld, which seek to determine linkages between age structure and the diversity and abundance of forest fauna populations. This project integrated measurements of structural attributes derived from a canopy-height elevation model with results from a geometrical-optical/spectral mixture analysis model to map forest age structure at a landscape scale. The availability of multiple-scale data allows the transfer of high-resolution attributes to landscape scale monitoring. Multispectral image data were obtained from a DMSV (Digital Multi-Spectral Video) sensor over St Mary's State Forest in Southeast Queensland, Australia. Local scene variance levels for different forest tapes calculated from the DMSV data were used to optimize the tree density and canopy size output in a geometric-optical model applied to a Landsat Thematic Mapper (TU) data set. Airborne laser scanner data obtained over the project area were used to calibrate a digital filter to extract tree heights from a digital elevation model that was derived from scanned colour stereopairs. The modelled estimates of tree height, crown size, and tree density were used to produce a decision-tree classification of forest successional stage at a landscape scale. The results obtained (72% accuracy), were limited in validation, but demonstrate potential for using the multi-scale methodology to provide spatial information for forestry policy objectives (ie., monitoring forest age structure).
Resumo:
Understanding the pattern in which adult drosophilids of different species are distributed across and within different vegetation types is necessary for accurate interpretation of their local ecology and diversity. Such studies have been conducted mainly in temperate regions, and there is no basis for extrapolating their conclusions to tropical areas. This study describes the vertical distribution (0-20 m) of drosophilids attracted to banana baits in five different vegetation types in subtropical eastern Australia including open woodland, and rain-forest types. The distribution of most of the 15 common species could be characterized three-dimensionally by vegetation type and height above forest floor. Only one species, Scaptodrosophila lativittata, was common in all vegetation types and it was a canopy species in rain forests and a ground-level species in open woodland. Vertical distribution of some species clearly matched that of their larval hosts, but it did not in others. For example, the fungivore Leucophenga scutellata was mostly trapped well above the forest floor, yet it breeds at ground level, suggesting behavioural mode can influence vertical distributions. We conclude that the vertical dimension, although still poorly understood in relation to drosophilid habitats, needs to be taken into account when conducting and interpreting studies aimed at understanding drosophilid populations and communities in the subtropics.
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Fifty single oospore progeny were established from an in vitro mating of A1 and A2 mating type isolates of Phytophthora cinnamomi from South Africa. Forty-nine progeny were identified as F-1 hybrids using seven random amplified polymorphic DNA (RAPD) primers, and one was a selfed isolate of the A1 mating type parent. Among the hybrid progeny, 24 and 25 were A1 and A2 mating type, respectively. Aggressiveness of progeny and parental isolates was assessed on 1-year-old seedlings of Eucalyptus smithii. The mean aggressiveness of hybrid oosporic isolates, expressed as lesion length, was significantly (P = 0.0001) lower than that of the parental isolates. No significant difference in aggressiveness of A1 and A2 mating type F-1 hybrid isolates was observed. This is the first report demonstrating sexual recombination in vitro in P. cinnamomi.
Resumo:
We investigated the phylogeography of two closely related Australian frog species from open forest habitats, Limnodynastes tasmaniensis and L. peronii, using mitochondrial ND4 sequence data. Comparison of our results with previous work on Litoria fallax allowed us to test the generality of phylogeographic patterns among non-rainforest anurans along the east coast of Australia. In general, there was no strong evidence for congruence between overall patterns of genetic structure in the three species. However, phylogenetic breaks congruent with the position of the Burdekin Gap were detected at some level in all species. As previously noted for closed forest taxa, this area of dry habitat appears to have been an important influence on the evolution of several open forest taxa. There were broad geographic similarities in the phylogenetic structuring of southern populations of L. peronii and L. tasmaniensis. Contrarily, although the McPherson Range has previously been noted to coincide geographically with a major mtDNA phylogenetic break in Litoria fallax this pattern is not apparent in L. peronii or L. tasmaniensis. It appears that major phylogeographic splits within L. peronii and L. tasmaniensis may predate the Quaternary. We conclude that phylogeographies of open forest frogs are complex and more difficult to predict than for rainforest taxa, mainly due to an absence of palaeomodels for historical distributions of non-rainforest habitats. (C) 2001 The Linnean Society of London.
Resumo:
Loblolly pine ( Pinus taeda L.) seeds from sources with a mild climate under maritime influence (North Carolina) required shorter moist chilling to achieve maximum germination vigor than seeds from sources with a harsher continental climate (Oklahoma). Solid matrix priming (SMP) for 6 d achieved as much as 60 d of moist chilling to improve rapidity, synchrony and completeness of germination for three of the four families studied. SMP after moist chilling increased the rapidity, synchrony and completeness of germination. The benefit of SMP was greatest for non-stratified seeds and the benefit decreased with length of moist chilling. In general, delaying planting for one week after SMP had minor effects on germination when seeds were kept in the SMP matrix at 4 degreesC. Delayed planting after SMP can increase germination rapidity and synchrony of seeds that have received long moist chilling and reduce the benefit of SMP in non-moist-chilled seeds.
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Sympatric individuals of Rattus fuscipes and Rattus leucopus, two Australian native rats from the tropical wet forests of north Queensland, are difficult to distinguish morphologically and are often confused in the field. When we started a study on fine-scale movements of these species, using microsatellite markers, we found that the species as identified in the field did not form coherent genetic groups. In this study, we examined the potential of an iterative process of genetic assignment to separate specimens from distinct (e.g. species, populations) natural groups. Five loci with extensive overlap in allele distributions between species were used for the iterative process. Samples were randomly distributed into two starting groups of equal size and then subjected to the test. At each iteration, misassigned samples switched groups, and the output groups from a given round of assignment formed the input groups for the next round. All samples were assigned correctly on the 10th iteration, in which two genetic groups were clearly separated. Mitochondrial DNA sequences were obtained from samples from each genetic group identified by assignment, together with those of museum voucher specimens, to assess which species corresponded to which genetic group. The iterative procedure was also used to resolve groups within species, adequately separating the genetically identified R. leucopus from our two sampling sites. These results show that the iterative assignment process can correctly differentiate samples into their appropriate natural groups when diagnostic genetic markers are not available, which allowed us to resolve accurately the two R. leucopus and R. fuscipes species. Our approach provides an analytical tool that may be applicable to a broad variety of situations where genetic groups need to be resolved.
Resumo:
Forests, and particularly those where native and mixed species are gown, provide a variety of non-wood values, important among which are recreation and environmental services. Substantial progress has been made in recent years in estimating economic values on these services. A considerable amount of research on forest values has been carried out recently in tropical and sub-tropical eastern Australia, some of which is reported in the following papers. The need for estimates of non-wood forest benefits is apparent, and it is clear that further development of techniques and a greater understanding of the way these values can be integrated into public-sector decision making is required.