965 resultados para Conservation Strategies


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The increase in coastal storm frequency and intensity expected under most climate change scenarios is likely to substantially modify beach configuration and associated habitats. This study aimed to analyze the impact of coastal storms on a nesting population of the endangered Piping Plover (Charadrius melodus melodus) in southeastern New Brunswick, Canada. Previous studies have shown that numbers of nesting Piping Plovers may increase following storms that create new nesting habitat at individual beaches. However, to our knowledge, no test of this pattern has been conducted over a regional scale. We hypothesized that Piping Plover abundance would increase after large coastal storms occurring during the nonbreeding season. However, we expected a delay in the colonization of newly created habitat owing to low-density populations, combined with high site fidelity of adults and high variability in survival rate of subadults. We tested this hypothesis using a 27-year (1986-2012) data set of Piping Plover abundance and productivity (nesting pairs and fledged young) collected at five sites in eastern New Brunswick. We identified 11 major storms that could potentially have modified Piping Plover habitat over the study period. The number of fledged young increased three years after a major storm, but the relationship was much weaker for the number of nesting pairs. These findings are consistent with the hypothesized increase in suitable habitat after coastal storms. Including storm occurrence with other factors influencing habitat quality will enhance Piping Plover conservation strategies.

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Many populations have recovered from severe bottlenecks either naturally or through intensive conservation management. In the past, however, few conservation programs have monitored the genetic health of recovering populations. We conducted a conservation genetic assessment of a small, reintroduced population of Mauritius Kestrel (Falco punctatus) to determine whether genetic deterioration has occurred since its reintroduction. We used pedigree analysis that partially accounted for individuals of unknown origin to document that (1) inbreeding occurred frequently (2.6% increase per generation; N-el = 18.9), (2) 25% of breeding pairs were composed of either closely or moderately related individuals, (3) genetic diversity has been lost from the population (1,6% loss per generation; N-ev = 32.1) less rapidly than the corresponding increase in inbreeding, and (4) ignoring the contribution of unknown individuals to a pedigree will bias the metrics derived from that pedigree, ultimately obscuring the prevailing genetic dynamics. The rates of inbreeding and loss of genetic variation in the subpopulation of Mauritius Kestrel we examined were extreme and among the highest yet documented in a wild vertebrate population. Thus, genetic deterioration may affect this population's long-term viability. Remedial conservation strategies are needed to reduce the impact of inbreeding and loss of genetic variation in this species, We suggest that schemes to monitor genetic variation after reintroduction should be an integral component of endangered species recovery programs

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Impatiens noli-tangere is scarce in the UK and probably only native to the Lake District and Wales. It is the sole food plant for the endangered moth Eustroma reticulattum. Significant annual fluctuations in the size of I. noli-tangere populations endanger the continued presence of E. reticulatum in the UK. In this study, variation in population size was monitored across native populations of L noli-tangere in the English Lake District and Wales. In 1998, there was a crash in the population size of all metapopulations in the Lake District but not of those found in Wales. A molecular survey of the genetic affinities of samples in 1999 from both regions and a reference population from Switzerland was performed using AFLP and ISSR analyses. The consensus UPGMA dendrogram and a PCO scatter plot revealed clear differentiation between the populations of L noli-tangere in Wales and those in the Lake District. Most of the genetic variation in the UK (H-T= 0.064) was partitioned between (G(ST) = 0.455) rather than within (H-S = 0.034) regions, inferring little gene flow occurs between regions. There was similar bias towards differentiation between metapopulations in Wales, again consistent with low levels of interpopulation gene flow. This contrasts with far lower levels of differentiation in the Lake District which suggests modest rates of gene flow may occur between populations. It is concluded that in the event of local extinction of sites or populations, reintroductions should be restricted to samples collected from the same region. We then surveyed climatic variables to identify those most likely to cause local extinctions. Climatic correlates of population size were sought from two Lake District metapopulations situated close to a meteorological station. A combination of three climatic variables common to both sites explained 81-84% of the variation in plant number between 1990 and 2001. Projected trends for these climatic variables were used in a Monte Carlo simulation which suggested an increased risk of I. noli-tangere population crashes by 2050 at Coniston Water. but not at Derwentwater. Implications of these findings for practical conservation strategies are explored. (C) 2003 Elsevier Ltd. All rights reserved.

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1. Wild bees are one of the most important groups of pollinators in the temperate zone. Therefore, population declines have potentially negative impacts for both crop and wildflower pollination. Although heavy metal pollution is recognized to be a problem affecting large parts of the European Union, we currently lack insights into the effects of heavy metals on wild bees. 2. We investigated whether heavy metal pollution is a potential threat to wild bee communities by comparing (i) species number, (ii) diversity and (iii) abundance as well as (iv) natural mortality of emerging bees along two independent gradients of heavy metal pollution, one at Olkusz (OLK), Poland and the other at Avonmouth (AVO), UK. We used standardized nesting traps to measure species richness and abundance of wild bees, and we recorded the heavy metal concentration in pollen collected by the red mason bee Osmia rufa as a measure of pollution. 3. The concentration of cadmium, lead and zinc in pollen collected by bees ranged from a background level in unpolluted sites [OLK: 1·3, 43·4, 99·8 (mg kg−1); AVO: 0·8, 42·0, 56·0 (mg kg−1), respectively] to a high level on sites in the vicinity of the OLK and AVO smelters [OLK: 6·7, 277·0, 440·1 (mg kg−1); AVO: 9·3, 356·2, 592·4 (mg kg−1), respectively]. 4. We found that with increasing heavy metal concentration, there was a steady decrease in the number, diversity and abundance of solitary, wild bees. In the most polluted sites, traps were empty or contained single occupants, whereas in unpolluted sites, the nesting traps collected from 4 to 5 species represented by up to ten individuals. Moreover, the proportion of dead individuals of the solitary bee Megachile ligniseca increased along the heavy metal pollution gradient at OLK from 0·2 in uncontaminated sites to 0·5 in sites with a high concentration of pollution. 5. Synthesis and applications. Our findings highlight the negative relationship between heavy metal pollution and populations of wild bees and suggest that increasing wild bee richness in highly contaminated areas will require special conservation strategies. These may include creating suitable nesting sites and sowing a mixture of flowering plants as well as installing artificial nests with wild bee cocoons in polluted areas. Applying protection plans to wild pollinating bee communities in heavy metal-contaminated areas will contribute to integrated land rehabilitation to minimize the impact of pollution on the environment.

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Species distribution models (SDM) are increasingly used to understand the factors that regulate variation in biodiversity patterns and to help plan conservation strategies. However, these models are rarely validated with independently collected data and it is unclear whether SDM performance is maintained across distinct habitats and for species with different functional traits. Highly mobile species, such as bees, can be particularly challenging to model. Here, we use independent sets of occurrence data collected systematically in several agricultural habitats to test how the predictive performance of SDMs for wild bee species depends on species traits, habitat type, and sampling technique. We used a species distribution modeling approach parametrized for the Netherlands, with presence records from 1990 to 2010 for 193 Dutch wild bees. For each species, we built a Maxent model based on 13 climate and landscape variables. We tested the predictive performance of the SDMs with independent datasets collected from orchards and arable fields across the Netherlands from 2010 to 2013, using transect surveys or pan traps. Model predictive performance depended on species traits and habitat type. Occurrence of bee species specialized in habitat and diet was better predicted than generalist bees. Predictions of habitat suitability were also more precise for habitats that are temporally more stable (orchards) than for habitats that suffer regular alterations (arable), particularly for small, solitary bees. As a conservation tool, SDMs are best suited to modeling rarer, specialist species than more generalist and will work best in long-term stable habitats. The variability of complex, short-term habitats is difficult to capture in such models and historical land use generally has low thematic resolution. To improve SDMs’ usefulness, models require explanatory variables and collection data that include detailed landscape characteristics, for example, variability of crops and flower availability. Additionally, testing SDMs with field surveys should involve multiple collection techniques.

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1. Species’ distributions are likely to be affected by a combination of environmental drivers. We used a data set of 11 million species occurrence records over the period 1970–2010 to assess changes in the frequency of occurrence of 673 macro-moth species in Great Britain. Groups of species with different predicted sensitivities showed divergent trends, which we interpret in the context of land-use and climatic changes. 2. A diversity of responses was revealed: 260 moth species declined significantly, whereas 160 increased significantly. Overall, frequencies of occurrence declined, mirroring trends in less species-rich, yet more intensively studied taxa. 3. Geographically widespread species, which were predicted to be more sensitive to land use than to climate change, declined significantly in southern Britain, where the cover of urban and arable land has increased. 4. Moths associated with low nitrogen and open environments (based on their larval host plant characteristics) declined most strongly, which is also consistent with a land-use change explanation. 5. Some moths that reach their northern (leading edge) range limit in southern Britain increased, whereas species restricted to northern Britain (trailing edge) declined significantly, consistent with a climate change explanation. 6. Not all species of a given type behaved similarly, suggesting that complex interactions between species’ attributes and different combinations of environmental drivers determine frequency of occurrence changes. 7. Synthesis and applications. Our findings are consistent with large-scale responses to climatic and land-use changes, with some species increasing and others decreasing. We suggest that land-use change (e.g. habitat loss, nitrogen deposition) and climate change are both major drivers of moth biodiversity change, acting independently and in combination. Importantly, the diverse responses revealed in this species-rich taxon show that multifaceted conservation strategies are needed to minimize negative biodiversity impacts of multiple environmental changes. We suggest that habitat protection, management and ecological restoration can mitigate combined impacts of land-use change and climate change by providing environments that are suitable for existing populations and also enable species to shift their ranges.

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Paepalanthus subgenus Xeractis (Eriocaulaceae) comprises 28 recognized species endemic to the Espinhaco Range, in Minas Gerais state, Brazil. Most species of the subgenus are restricted to small localities and critically endangered, but still in need of systematic study. The monophyly of the subgenus has already been tested, but only with a few species. Our study presents the first phylogenetic hypothesis within the group, based on morphology. A maximum parsimony analysis was conducted on a matrix of 30 characters for 30 terminal taxa, including all species of the subgenus and two outgroups. The biogeographical hypotheses for the subgenus were inferred based on dispersal-vicariance analysis (DIVA). The analysis provided one most-parsimonious hypothesis that supports most of the latest published subdivisions (sections and series). However, some conflicts remain concerning the position of a few species and the relationships between sections. The distribution and origin(s) of microendemism are also discussed, providing the ground for conservation strategies to be developed in the region. (C) 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 167, 137-152.

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Roads and topography can determine patterns of land use and distribution of forest cover, particularly in tropical regions. We evaluated how road density, land use, and topography affected forest fragmentation, deforestation and forest regrowth in a Brazilian Atlantic Forest region near the city of Sao Paulo. We mapped roads and land use/land cover for three years (1962, 1981 and 2000) from historical aerial photographs, and summarized the distribution of roads, land use/land cover and topography within a grid of 94 non-overlapping 100 ha squares. We used generalized least squares regression models for data analysis. Our models showed that forest fragmentation and deforestation depended on topography, land use and road density, whereas forest regrowth depended primarily on land use. However, the relationships between these variables and forest dynamics changed in the two studied periods; land use and slope were the strongest predictors from 1962 to 1981, and past (1962) road density and land use were the strongest predictors for the following period (1981-2000). Roads had the strongest relationship with deforestation and forest fragmentation when the expansions of agriculture and buildings were limited to already deforested areas, and when there was a rapid expansion of development, under influence of Sao Paulo city. Furthermore, the past(1962)road network was more important than the recent road network (1981) when explaining forest dynamics between 1981 and 2000, suggesting a long-term effect of roads. Roads are permanent scars on the landscape and facilitate deforestation and forest fragmentation due to increased accessibility and land valorization, which control land-use and land-cover dynamics. Topography directly affected deforestation, agriculture and road expansion, mainly between 1962 and 1981. Forest are thus in peril where there are more roads, and long-term conservation strategies should consider ways to mitigate roads as permanent landscape features and drivers facilitators of deforestation and forest fragmentation. (C) 2009 Elsevier B.V. All rights reserved.

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Edge effects are suggested to have great impact on the persistence of species in fragmented landscapes. We tested edge avoidance by forest understory passerines in the Brazilian Atlantic Rainforest and also compared their mobility and movement patterns in contiguous and fragmented landscapes to assess whether movements would increase in the fragmented landscape. Between 2003 and 2005, 96 Chiroxiphia caudata, 38 Pyriglena leucoptera and 27 Sclerurus scansor were radio-tracked. The most strictly forest species C. caudata and S scansor avoided forest edges while P leucoptera showed affinities for the edge Both sensitive species showed larger mean step length and maximal observed daily distance in the fragmented forest versus the unfragmented forest. P. leucoptera did not show any significant difference. There were no significant differences in proportional daily home range use for any of the three species. Our results suggested that fragmentation and the consequent increase in edge areas do influence movement behavior of sensitive forest understory birds that avoided the use of edges and increased the speed and distance they covered daily. For the most restricted forest species, it would be advisable to protect larger patches of forest instead of many small or medium fragments connected by narrow corridors. However, by comparing our data with that obtained earlier, we concluded that movement behavior of resident birds differs from that of dispersing birds and might not allow to infer functional connectivity or landscape-scale sensitivity to fragmentation; a fact that should be taken into consideration when suggesting conservation strategies. (c) 2008 Elsevier Ltd. All rights reserved.

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Establishing effective networks of protected areas (PAS) is one of the major goals of conservation strategies worldwide. However, the success of PAS in promoting biodiversity conservation depends on their integration to local and regional contexts, reducing and mitigating human impacts originating from buffer zones. Community perceptions affect interactions between residents and PAS, and thereby conservation effectiveness. Research at Tocantins state (northern Brazilian Cerrado), aimed to analyse local community perceptions of four PAs, discussing how different factors may influence these. Perceptions were assessed through standardized interviews applied to PA employees and 275 local inhabitants. There was modest community participation in PA establishment and management. Residents were aware of the PAS` existence, but were unfamiliar with their goals. Length of residency and occupation of inhabitants influenced their PA perceptions, shaping different people-park relations in each of the four studied PAs. Involvement of local residents in PA planning and management represents a central strategy to strengthen local support for PAS over the long term. In those areas that still have settlements inside their boundaries, community relocation should follow a careful participatory process to avoid significant changes in local perceptions and attitudes towards these PAS, crucial for conserving Brazilian biodiversity.

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Gramastacus insolitus is a very small non-burrowing Australian freshwater crayfish with a restricted distribution, occurring almost exclusively in seasonal habitats throughout its range. It is listed as a threatened species but its strategy for surviving dry periods was unknown. Eight seasonal surveys of crayfish distribution showed that members of G. insolitus were never found at sites that were outside the distribution of two larger burrowing freshwater crayfish species, Geocharax falcata and Cherax destructor. Excavation of 80 burrows of members of G. falcata and C. destructor in three different seasonal habitats in the Grampians National Park, Victoria, Australia, revealed that individuals of G. insolitus found refuge from drying by estivating in cracks and shallow depressions at the side of the main burrow tunnels constructed by larger species. Members of G. insolitus were not found estivating at the surface, such as under fallen wood, nor was it usually found in crayfish burrows unoccupied by the host crayfish. This study indicates that members of G. insolitus are commensal upon larger crayfish species, using their burrows to survive the seasonal drying of their habitat. Conservation strategies for populations of G. insolitus will need to consider co-existing species of burrowing crayfish.

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Humla Province is a remote mountainous region of northwest Nepal. The climate is harsh and the local people are extremely poor. Most people endure a subsistence culture, living in traditional housing. Energy for cooking and heating comes from fuelwood, supplies of which are diminishing. In order to improve the indoor environment and reduce fuelwood use, smokeless stoves are being introduced to replace the open fire in Humli homes. There is some concern, however, that comfort levels may not be as acceptable with these stoves. The aim of this research was therefore to investigate ways in which the comfort levels in traditional Humli housing might be improved using simple and low cost strategies. Temperature data was recorded in four rooms of a traditional Humli home over a 12-day period and used with fuelwood data to validate a TRNSYS simulation model of the house. This model was then used to evaluate the impact on comfort levels in the house of various energy conservation strategies using PMV and PPD indicators. As a single strategy, it was found that reducing infiltration of outside air was likely to be more effective than increasing the insulation level in the ceilings. The most successful strategy, however, was the creation of sunspaces at the entrances to the living rooms. This strategy increased average internal temperatures by 1.7 and 2.3 °C. In combination with increased insulation levels, the sunspaces reduced comfort dissatisfaction levels by over 50%.

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Planning for resilience is the focus of many marine conservation programs and initiatives. These efforts aim to inform conservation strategies for marine regions to ensure they have inbuilt capacity to retain biological diversity and ecological function in the face of global environmental change – particularly changes in climate and resource exploitation. In the absence of direct biological and ecological information for many marine species, scientists are increasingly using spatially-explicit, predictive-modeling approaches. Through the improved access to multibeam sonar and underwater video technology these models provide spatial predictions of the most suitable regions for an organism at resolutions previously not possible. However, sensible-looking, well-performing models can provide very different predictions of distribution depending on which occurrence dataset is used. To examine this, we construct species distribution models for nine temperate marine sedentary fishes for a 25.7 km2 study region off the coast of southeastern Australia. We use generalized linear model (GLM), generalized additive model (GAM) and maximum entropy (MAXENT) to build models based on co-located occurrence datasets derived from two underwater video methods (i.e. baited and towed video) and fine-scale multibeam sonar based seafloor habitat variables. Overall, this study found that the choice of modeling approach did not considerably influence the prediction of distributions based on the same occurrence dataset. However, greater dissimilarity between model predictions was observed across the nine fish taxa when the two occurrence datasets were compared (relative to models based on the same dataset). Based on these results it is difficult to draw any general trends in regards to which video method provides more reliable occurrence datasets. Nonetheless, we suggest predictions reflecting the species apparent distribution (i.e. a combination of species distribution and the probability of detecting it). Consequently, we also encourage researchers and marine managers to carefully interpret model predictions.

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1. Comprehensive knowledge of the fundamental spatial ecology of marine species is critical to allow the identification of key habitats and the likely sources of anthropogenic threats, thus informing effective conservation strategies. 2. Research on migratory marine vertebrates has lagged behind many similar terrestrial animal groups, but studies using electronic tagging systems and molecular techniques offer great insights. 3. Marine turtles have complex life history patterns, spanning wide spatio-temporal scales. As a result of this multidimensional complexity, and despite extensive effort, there are no populations for which a truly holistic understanding of the spatial aspects of the life history has been attained. There is a particular lack of information regarding the distribution and habitats utilized during the first few years of life. 4. We used satellite tracking technology to track individual turtles following nesting at the green turtle Chelonia mydas nesting colony at Poilão Island, Guinea Bissau; the largest breeding aggregation in the eastern Atlantic. 5. We further contextualize these data with pan-Atlantic molecular data and oceanographic current modelling to gain insights into likely dispersal patterns of hatchlings and small pelagic juveniles. 6. All adult turtles remained in the waters of West Africa, with strong connectivity demonstrated with Banc D’Arguin, Mauritania. 7. Despite shortcomings in current molecular markers, we demonstrate evidence for profound sub-structuring of marine turtle stocks across the Atlantic; with a high likelihood based on oceanographic modelling that most turtles from Guinea-Bissau are found in the eastern Atlantic. 8. Synthesis and applications. There is an increased need for a better understanding of spatial distribution of marine vertebrates demonstrating life histories with spatio-temporal complexity. We propose the synergistic use of the technologies and modelling used here as a working framework for the future rapid elucidation of the range and likely key habitats used by the different life stages from such species.

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Long-distance migrations are among the wonders of the natural world, but this multi-taxon review shows that the characteristics of species that undertake such movements appear to make them particularly vulnerable to detrimental impacts of climate change. Migrants are key components of biological systems in high latitude regions, where the speed and magnitude of climate change impacts are greatest. They also rely on highly productive seasonal habitats, including wetlands and ocean upwellings that, with climate change, may become less food-rich and predictable in space and time. While migrants are adapted to adjust their behaviour with annual changes in the weather, the decoupling of climatic variables between geographically separate breeding and non-breeding grounds is beginning to result in mistimed migration. Furthermore, human land-use and activity patterns will constrain the ability of many species to modify their migratory routes and may increase the stress induced by climate change. Adapting conservation strategies for migrants in the light of climate change will require substantial shifts in site designation policies, flexibility of management strategies and the integration of forward planning for both people and wildlife. While adaptation to changes may be feasible for some terrestrial systems, wildlife in the marine ecosystem may be more dependent on the degree of climate change mitigation that is achievable.