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1.
In Mediterranean areas, river systems are key for maintaining regional biodiversity by providing a high diversity of habitats. We studied bird community recovery for 9 years (2001–2009) during landscape restoration and Guadiamar Green Corridor establishment in the area affected by the Aznalcóllar mine spill (SW Spain, 1998). One year following plant restoration (3 years after the spill), values for α‐ and β‐bird species diversity were high, sooner than reported for similar restoration processes elsewhere. Species richness, ecological diversity, and abundance increased only slightly in the following 8 years. Overlap between communities in sequential years, measured by similarity indexes, increased throughout the study period to about 70% during final survey years, and most breeding bird species present before the accident again inhabit the area. Only 5 years after the mine accident, bird communities in the restored site were similar in species richness, abundance, and diversity to an unaffected reference site; redundancy analysis demonstrated that bird communities were also similar between the reference river and the Guadiamar. Despite the severity of the mine accident, our results suggest a swift recovery of the bird community. We attribute this success to the rapid restoration of habitat availability and the resilience of the birds. This long‐term study contributes to our limited knowledge of bird species response to habitat restoration following toxic spills in Mediterranean habitats.  相似文献   

2.
Wildfires are recognized as natural disturbances that have shaped landscape structure and ecosystem composition in many regions of the world. As ectotherms, many Mediterranean reptiles are expected to benefit from the thermal quality of open areas created by fires. However, not all the reptile species respond positively to this pattern. We have explored the response to fire of a Mediterranean reptile community in a protected area of the northeastern Iberian Peninsula. We visually searched for reptiles at 102 sites, including unburnt, recently burnt (2003), and old burnt (1985–1986) localities. The number of reptiles and species richness was higher at burnt sites, and both were related to several variables of the habitat structure. Accordingly, between the two most common species in recently burnt sites, Podarcis hispanica declined in old fire habitats whereas Psammodromus algirus did not. Snakes did not differ between burnt and unburnt areas, although the ambush predator viper Vipera latastei was found more frequently in unburnt habitats. Our results imply that there are different succession trajectories for Mediterranean reptile species according to their habitat preferences, life history traits, and dietary specialization. The study area has been drastically human-altered in the last 100 years by agriculture, pine reforestation, agricultural abandonment, and wildfires. These land use changes drastically alter the vegetation cover, favoring some reptiles and damaging others, and finally can promote local extinctions of sensitive species to habitat shifts.  相似文献   

3.
The greatest threat to biodiversity is the alteration and destruction of habitats, and one of the causes is tree plantation, which normally are monospecific and unnatural high-density forest stands. In Spain these contain mainly Pinus species, and cover 25% of the forested area. Due to their dense canopy cover, these monocultures harbor poor communities in terms of species richness and abundance of other organisms, such as reptiles. In November 2014, wind storms affected a pine plantation in the western end of the Sierra Nevada Natural Park, totally or partially knocking down pines 65 years old. We have studied the response of the reptile community in the affected plots three and five years after the disturbance. Due to the low thermal quality of pine plantations for reptiles, we hypothesized that reptile community metrics (abundance and species richness) would be positively affected by this perturbation. We found greater richness and density of reptiles in the plots affected by maximum and intermediate disturbance than in the non-affected plots. We conclude that natural catastrophic events such as wind storms can diversify reptile communities in Mediterranean pine plantations thanks to a rapid response of generalist reptile species.  相似文献   

4.
Exploring elevational patterns in species richness and their underlying mechanisms is a major goal in biogeography and community ecology. Reptiles can be powerful model organisms to examine biogeographical patterns. In this study, we examine the elevational patterns of reptile species richness and test a series of hypotheses that may explain them. We sampled reptile communities along a tropical elevational gradient (100–1,500 m a.s.l.) in the Western Ghats of India using time‐constrained visual encounter surveys at each 100‐m elevation zone for 3 years. First, we investigated species richness patterns across elevation and the support of mid‐domain effect and Rapoport's rule. Second, we tested whether a series of bioclimatic (temperature and tree density) and spatial (mid‐domain effect and area) hypotheses explained species richness. We used linear regression and AICc to compare competing models for all reptiles, and each of the subgroups: snakes, lizards, and Western Ghats’ endemics. Overall reptile richness and lizard richness both displayed linear declines with elevation, which was best explained by temperature. Snake richness and endemic species richness did not systematically vary across elevation, and none of the potential hypotheses explained variation in them. This is the first standardized sampling of reptiles along an elevational gradient in the Western Ghats, and our results agree with the global view that temperature is the primary driver of ectotherm species richness. By establishing strong reptile diversity–temperature associations across elevation, our study also has implications for the impact of future climate change on range‐restricted species in the Western Ghats.  相似文献   

5.
Studies on environmental enrichment for reptiles are lacking in the scientific literature. Although the literature reflects a limited take on reptile enrichment in the zoological community, it may not be the case in reality as enrichment is generally considered an important aspect of the care of nonhuman animals in captivity. This project investigated the current state of reptile enrichment as it is being used in zoos. Although respondents were disproportionately accredited by the Association of Zoos and Aquariums, the results showed many forms of enrichment being used for reptiles in zoos and happening at much greater levels than what has been suggested in the scientific literature. There were significant differences between a) reptile groups for each form of enrichment, and b) enrichment forms within each reptile group, except with the use of natural enrichment devices and structural/habitat design, which did not differ across all reptile groups. Enrichment goals, assessment methods, and sources of information for reptile enrichment used by zoos suggest the need for more scientific publications for facilities to make evidence-based decisions to improve the welfare of reptiles in captivity.  相似文献   

6.
This research is part of the Guadiamar River Basin (S Iberian Peninsula) Recovery Monitoring Programme. The main aim of this Program is to establish whether the management of the area affected by the Aznalcóllar mining accident (1998) has indeed led to a regeneration process and to select applicable parameters for the future following program. The Carabidae Family was selected to analyse these questions since it is one of the most effective bio-indicator taxa belonging to the soil fauna. Previous research carried out in different areas from Europe suggested that the mean individual biomass (MIB) of ground beetles could be used as a suitable measure to assess the environment stage. This paper analyses the progress made by the ground beetles community 6 years after the disaster and aims to validate the usefulness of MIB as a means of assessing the recovery process of the Guadiamar Green Corridor. To evaluate changes in the research area over time, correlation and classification analysis have been performed. Indices commonly used in population dynamics were calculated in addition to the MIB. Results allow us to infer two conclusions: (I) The area as a whole is undergoing a significant recovery process. However, this process has not yet reached the expected levels of a non-affected basin in the southern Iberian Peninsula. (II) The application of the MIB index of Carabid beetles could be a useful tool to assess long-term environmental changes. However, this proposal requires further validation.  相似文献   

7.
Restoration can be important in slowing, or reducing, rates of biodiversity loss, but needs to consider the factors influencing fauna recolonization as part of the recovery process. Although many studies of factors influencing faunal recolonization have examined the influence of in situ site factors, fewer have examined the influence of neighborhood landscape factors, especially in landscapes with permeable matrices. To assess the relative influence of landscape and site factors on reptile recolonization in a production landscape with a permeable matrix, we surveyed reptiles at intact reference sites and post‐mining restoration sites (3–20 years post‐mining [YPM]) in a forest ecosystem in southwestern Australia. Reptile assemblages in restoration sites never converged on those in reference habitat. Reptile species composition and individual species abundances (>20 detections) in restoration sites were primarily influenced by site factors such as canopy height, litter cover, and coarse woody debris volume, and not by landscape factors. We suggest that the most common reptile species in our study area are primarily influenced by site factors, not landscape factors, and most reptiles detected in restoration sites were present by 3–4 YPM. Therefore, it is likely that habitat suitability is the main barrier to most species' recolonization of restoration sites in landscapes with permeable matrices. Management should continue to focus on restoring microhabitats and vegetation structure, which is similar to reference habitat to promote recolonization of restoration sites by reptiles.  相似文献   

8.
Refuges are crucial for most animal species as they offer essential protection against predators and provide buffered environmental conditions to their occupants. Our data show that northern populations of the threatened ocellated lizard (Timon lepidus) depend on the availability of the burrows excavated by the European rabbit (Oryctolagus cuniculus). In the last decade, a severe decline in rabbit populations has had a disastrous effect on lizard numbers. To compensate for the lack of refuges, artificial shelters were constructed in autumn 2005 and 2007 and were monitored the following years (2006–2009). Most of the artificial refuges were rapidly occupied by lizards, notably juveniles, suggesting that this technique was successful to improve lizard habitat. Because other factors such as food resources might be also crucial, further assessments are required to determine if artificial refuges are sufficient to stem population decline. These results nonetheless provide an encouraging option to maintain and/or to restore threatened populations, for instance through a buffering of rabbit burrow fluctuations. More generally, the availability of suitable refuges (e.g. natural or artificial) is likely to be a central component for the conservation of many reptile species. The combination of empirical and experimental data further demonstrates that great attention must be paid to the structure and distribution of the refuges and that simple practical actions can effectively improve habitat quality for threatened species.  相似文献   

9.
Artificial refuges (cover boards) are commonly used to survey and monitor herpetofauna in many parts of the world. Despite the extensive use of artificial refuges in mesic environments, their effectiveness for detecting amphibians in temperate zones has rarely been examined. We compared amphibian detection probabilities between two survey methods; active searches of natural habitat and artificial refuges of three different types (corrugated steel, roofing tiles and timber railway sleepers). Our study area included five bioregions encompassing a 1180‐km latitudinal gradient across a modified, temperate eucalypt woodland vegetation community in south‐eastern Australia. We deployed 14 778 artificial refuges in terrestrial environments, within patches of remnant vegetation, and collected presence and abundance data on herpetofauna between 1999 and 2017. We used Bayesian logistic regression to identify the most effective survey method for detecting frog species across all bioregions. We modelled frog detections by fitting survey method, time since refuge deployment and rainfall prior to each survey. We detected 3970 individuals from 18 frog species. Overall, we found active searches and timber substrates most effective for detecting a broad range of species, although detection rates were driven by the numerically abundant spotted marsh frog Limnodynastes tasmaniensis. Timber refuges were effective for detecting several burrowing species, whereas active searches were effective at detecting habitat generalists. Quadratic effects of rainfall prior to survey as opposed to linear effects of time since artificial refuge placement was important in explaining frog detection rates in some bioregions. Active searches, timber railway sleepers and sheets of corrugated steel provide complimentary survey methods for detecting amphibians, although detection rates are influenced by rainfall patterns. Artificial refuges provide a time‐effective and standardized method for studying amphibians in their non‐breeding terrestrial environment and should be incorporated into future surveys and biodiversity monitoring programmes.  相似文献   

10.
Fire has impact on reptile communities with marked shifts in community composition between burnt and unburnt areas. These shifts are often related to the preference of reptile species throughout early or late post-fire successional habitats. Areas located in transition zones between bioregions harbor complex reptile communities with a mixture of biogeographic affinities. In these biogeographic crossroads, since fire simplifies the habitat structure, we expected simpler (lower alpha diversity) and more similar (lower beta diversity) reptile communities within burnt than within unburnt localities. We have tested this hypothesis in a transition zone between the Atlantic and Mediterranean bioregions in northern Portugal. Reptiles were surveyed in five localities (8 times per locality) along fire edges in which each locality was composed of one burnt and one unburnt transect. In total, 588 reptiles from 10 species were recorded. Unburnt transects had higher alpha and beta diversity and higher relative abundance of non-Mediterranean individuals than did burnt transects. A redundancy analysis also showed contrasting responses of Mediterranean and non-Mediterranean species, the former increasing and the latter decreasing after fire. Our study demonstrates that fire reduced the complexity of the reptile community, with benefits towards Mediterranean species due to its environmental preferences and long evolutionary association to fire. In biogeographic crossroads such as the study area, the retention of long unburnt vegetation is expected to maintain more diverse reptile communities.  相似文献   

11.
From 1985 through 1990, the herpetofauna of a temporary pond in an uplands longleaf pine sandhills community in north-central Florida was monitored. A drift fence completely encircled the pond. Animals were captured in pitfall traps and marked as they entered and exited the pond basin. I captured 16 155 individuals of 42 species (16 amphibians, 26 reptiles). The species richness, diversity (using Margalef's Diversity Index) and dominance (using the Berger-Parker Index) varied among years. Between 62.5% and 87.5% of the amphibian species and 65% to 81% of the reptile species were captured in any one year. Daily amphibian capture was positively correlated with rainfall, whereas reptile capture was either not correlated or weakly negatively correlated with rainfall. Hydroperiod duration was not correlated with the numbers of either amphibians or reptiles captured. Neither the amphibian nor the reptile community showed any trends in diversity or dominance indices during the course of the study, although both communities were dominated by a few species. However, the species responsible for community dominance changed somewhat as the study progressed. Assessing the results of this study is hampered by the lack of comparable studies elsewhere, expected natural fluctuations of amphibian populations, and a prolonged drought, especially during the latter stages of the study. The herpetological community at Breezeway Pond does not appear to follow theoretical predictions of community response to stress. Temporary ponds are important centres of herpetofaunal biodiversity in uplands sandhills communities. Long-term studies are needed to monitor the composition, structure, and functional interactions of their resident species.  相似文献   

12.
Reptile populations are in decline globally, with total reptile abundance halving in the past half century, and approximately a fifth of species currently threatened with extinction. Research on reptile distributions, population trends, and trophic interactions can greatly improve the accuracy of conservation listings and planning for species recovery, but data deficiency is an impediment for many species. Environmental DNA (eDNA) can detect species and measure community diversity at diverse spatio‐temporal scales, and is especially useful for detection of elusive, cryptic, or rare species, making it potentially very valuable in herpetology. We aim to summarize the utility of eDNA as a tool for informing reptile conservation and management and discuss the benefits and limitations of this approach. A literature review was conducted to collect all studies that used eDNA and focus on reptile ecology, conservation, or management. Results of the literature search are summarized into key discussion points, and the review also draws on eDNA studies from other taxa to highlight methodological challenges and to identify future research directions. eDNA has had limited application to reptiles, relative to other vertebrate groups, and little use in regions with high species richness. eDNA techniques have been more successfully applied to aquatic reptiles than to terrestrial reptiles, and most (64%) of studies focused on aquatic habitats. Two of the four reptilian orders dominate the existing eDNA studies (56% Testudines, 49% Squamata, 5% Crocodilia, 0% Rhynchocephalia). Our review provides direction for the application of eDNA as an emerging tool in reptile ecology and conservation, especially when it can be paired with traditional monitoring approaches. Technologies associated with eDNA are rapidly advancing, and as techniques become more sensitive and accessible, we expect eDNA will be increasingly valuable for addressing key knowledge gaps for reptiles.  相似文献   

13.
Summary Species interactions, as revealed by historical introductions of predators and competitors, affect population densities and sometimes result in extinctions of island reptiles. Mongoose introductions to Pacific islands have diminished the abundance of diurnal lizards and in some cases have led to extinctions. Through these population level effects, biogeographic patterns are produced, such as the reciprocal co-occurrence pattern seen with the tuatara and its predator, the Polynesian rat, and with the tropical gecko competitorsHemidactylus frenatus andLepidodactylus lugubris in urban habitats in the Pacific. Although competition has led to changes in abundance and has caused habitat displacement and reduced colonization success, extinctions of established reptile populations usually occur only as a result of predation.These introductions, along with many manipulative experiments, demonstrate that present day competition and predation are potent forces shaping community structure and geographic distributions. The human introduction of species to islands can be viewed as an acceleration of the natural processes of range expansion and colonization. The immediate biotic consequences of these natural processes should be of the same intensity as those of the human introductions. Coevolution may subsequently act to ameliorate these interactions and reduce the dynamical response of one species to the other. The role played by coevolution in mediating interactions between competitors and predator and prey is highlighted by the susceptibility of predator-naive endemic species to introduced predators and the invalidity of species-poor communities.  相似文献   

14.
Artificial refuges are human-made structures that aim to create safe places for animals to breed, hibernate, or take shelter in lieu of natural refuges. Artificial refuges are used across the globe to mitigate the impacts of a variety of threats on wildlife, such as habitat loss and degradation. However, there is little understanding of the science underpinning artificial refuges, and what comprises best practice for artificial refuge design and implementation for wildlife conservation. We address this gap by undertaking a systematic review of the current state of artificial refuge research for the conservation of wildlife. We identified 224 studies of artificial refuges being implemented in the field to conserve wildlife species. The current literature on artificial refuges is dominated by studies of arboreal species, primarily birds and bats. Threatening processes addressed by artificial refuges were biological resource use (26%), invasive or problematic species (20%), and agriculture (15%), yet few studies examined artificial refuges specifically for threatened (Vulnerable, Endangered, or Critically Endangered) species (7%). Studies often reported the characteristics of artificial refuges (i.e. refuge size, construction materials; 87%) and surrounding vegetation (35%), but fewer studies measured the thermal properties of artificial refuges (18%), predator activity (17%), or food availability (3%). Almost all studies measured occupancy of the artificial refuges by target species (98%), and over half measured breeding activity (54%), whereas fewer included more detailed measures of fitness, such as breeding productivity (34%) or animal body condition (4%). Evaluating the benefits and impacts of artificial refuges requires sound experimental design, but only 39% of studies compared artificial refuges to experimental controls, and only 10% of studies used a before-after-control-impact (BACI) design. As a consequence, few studies of artificial refuges can determine their overall effect on individuals or populations. We outline a series of key steps in the design, implementation, and monitoring of artificial refuges that are required to avoid perverse outcomes and maximise the chances of achieving conservation objectives. This review highlights a clear need for increased rigour in studies of artificial refuges if they are to play an important role in wildlife conservation.  相似文献   

15.
Roads pose significant threats to reptiles, and understanding the varying perceptual biases of motorists to different taxa may help determine management strategies for urban roads around important refuges such as wetlands. We surveyed Western Australian motorists online, asking them to rank their degree of concern for animal welfare, vehicle damage, and personal safety when hypothetically involved in a vehicle collision with 10 different animal taxa, including reptiles. Respondents also ranked their rescue likelihood for these taxa. We then observed motorist responses to snakes and lizards in the field, where we placed rubber models and controls on the shoulder of an urban road bordering a wetland in Perth, Western Australia. We also estimated the probability of a reptile being struck while crossing the study road at two different road vehicle densities. The online survey respondents claimed high mean concern for the welfare of animals on roads (M = 8.02 ± 2.73 SD out of 10) and low concern for vehicle damage (M = 2.87 ± 2.75) and personal safety (M = 2.91 ± 2.88). Respondents also claimed high mean rescue likelihood (M = 7.06 ± 3.40). In contrast, motorists observed in the field generally ignored objects, including reptiles, on the roadside (79% of n = 1,500). There were no observed intentional strikes on reptiles, one motorist made a rescue attempt (bobtail lizard), and all other responses were to slow down or move away from the treatment. Estimates of strike probability for a reptile crossing the study road at a low traffic volume (2.23 vehicles·min-1) was > 75% for slow-moving (1 m·min-1) reptiles, but reduced to ≤ 16% if they were moving quickly (60 m·min-1). Although motorists did not intentionally strike model reptiles, surveyed attitudes did not directly translate to behavioral action, and crossing a road is risky for an urban reptile.  相似文献   

16.
The rapid loss and degradation of tropical forests threatens the maintenance of biodiversity across different spatial scales. Nevertheless, the extirpation and population decline of some disturbance-sensitive species may be compensated for by colonization and proliferation of disturbance-adapted species, thus allowing distributions of community-level attributes (e.g., abundance and diversity) to be preserved in human-modified tropical landscapes. To test this poorly assessed hypothesis we evaluated species- and community-level responses of amphibians and reptiles to differences in forest patch (patch size, shape, and distance to water bodies) and landscape metrics (old-growth forest cover, degree of fragmentation, and matrix composition) in the fragmented Lacandona rainforest, Mexico. We found that the abundance of several amphibian and reptile species was strongly associated with forest patch and landscape attributes, being particularly higher in larger patches surrounded by a greater forest cover. Such changes at the species level generated notable changes in reptile communities. In particular, the abundance, diversity, and evenness of reptile communities were strongly related to patch size, patch shape, and matrix composition. Yet, because of compensatory dynamics in amphibians, this group showed weak responses at the community level. Despite such compensatory dynamics, our results indicate that forest loss at the patch and landscape levels represents the main threat to both amphibians and reptiles, thus indicating that to preserve herpetological communities in this biodiversity hotspot, conservation initiatives should be focused on preventing further deforestation.  相似文献   

17.
安徽岭南自然保护区两栖爬行动物多样性及保护   总被引:5,自引:2,他引:5  
1998年7月至2000年10月,对岭南自然保护区进行了两栖爬行动物调查,发现有两栖动物19种(隶属7科9属),爬行动物32种(隶属9科23属),占安徽省两栖爬行动物种数的48.6%,而面积仅为全省的0.021%,被列入中国濒危动物红皮书的有16种之多。区系特点:东洋界成分占76%,东洋界古北界广布种占24%,无古北界成分(未定种一种不算在内)。非法捕捉已使这里的两栖爬行动物生存面临极大的威胁,建议在加大保护的宣传力度和严厉打击不法分子的同时,积极开展资源可持续利用的研究。  相似文献   

18.
Effects of perturbations to wildlife often are measured by changes in rates of encounter with animals during standardised surveys, such as along roads. Previous work has predicted that the invasion of toxic cane toads (Rhinella marina) through the Australian tropics will cause massive mortality of anuran-eating snakes, and influence abundances of other native species. We surveyed three adjacent road transects for nocturnal snakes and lizards, beginning shortly before toads arrived at this site near Darwin, in the Northern Territory. In the wet-seasons of four successive years, we conducted surveys on 591 nights; on 302 of these nights, all three transects were surveyed. We recorded 8,880 live cane toads and 3,365 live reptiles. Toad numbers increased over time on all three transects but encounters with 13 species of native reptiles varied inconsistently. Eight of the 13 species of native reptile showed no significant change in encounter rates following the arrival of toads. Of the five species that did change in encounter rates, only one taxon (the bluetongue skink, Tiliqua scincoides intermedia) declined across all three transects. Encounter rates of the other four species often increased on at least one transect but decreased on at least one other. Thus, either the impact of cane toads on counts of reptiles differed between nearby sites, or (more likely) other factors had more influence on reptile numbers. A consistent decrease in reptile numbers on the busiest road over the study period suggests that local snake populations were affected more by road-kill than by invasive toads. Without spatial replication, this decrease could have been interpreted as an impact of toad invasion.  相似文献   

19.
Finima Nature Park, situated in Bonny Island (Niger Delta, Nigeria), is a protected forested area placed within one of the most industrially developed (and environmentally polluted) regions of the whole African continent. Amphibian and reptile community composition in relation to season and microhabitat characteristics was studied, by a combination of field techniques, during the wet and dry seasons of 2007 and 2008. Overall, a total of 21 species of reptiles from nine families (with 668 individuals caught) and eight amphibian species from five families (492 individuals caught) were recorded. Nearly 94% of the amphibian individuals and most of the species were recorded, especially during the wet season, whereas most of the reptiles were found with no inter‐seasonal differences. However, Agama agama and Mabuya affinis were found especially during the dry season. As for microhabitat use, the reptile species showed a clear, aggregated preference for two microhabitat types (dry leaves and under logs), which are probably crucial when these animals need to lose body temperature to avoid overheating. Concerning amphibians, the various species used the available microhabitats in a way expectable from their main ecological traits, with toads differing from aquatic frogs, and these differing from arboreal frogs.  相似文献   

20.
Understanding the factors that regulate geographical variation in species richness has been one of the fundamental questions in ecology for decades, but our knowledge of the cause of geographical variation in species richness remains poor. This is particularly true for herpetofaunas (including amphibians and reptiles). Here, using correlation and regression analyses, we examine the relationship of herpetofaunal species richness in 245 localities across China with 30 environmental factors, which include nearly all major environmental factors that are considered to explain broad-scale species richness gradients in such theories as ambient energy, water–energy dynamics, productivity, habitat heterogeneity, and climatic stability. We found that the species richness of amphibians and reptiles is moderately to strongly correlated with most of the environmental variables examined, and that the best fit models, which include explanatory variables of temperature, precipitation, net primary productivity, minimum elevation, and range in elevation, explain ca 70% the variance in species richness for both amphibians and reptiles after accounting for sample area. Although water and temperature are important explanatory variables to both amphibians and reptiles, water variables explain more variance in amphibian species richness than in reptile species richness whereas temperature variables explain more variance in reptile species richness than in amphibian species richness, which is consistent with different physiological requirements of the two groups of organisms.  相似文献   

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