首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The aim of this study is to determine the conservation status of Scrophularia valdesii Ortega-Olivencia & Devesa, a threatened narrow endemism of the Duero Basin (central-western Spain and north-eastern Portugal, Lusitan Duriensean biogeographical sector), by using the IUCN (2001) IUCN Red List Categories and Criteria: version 3.1. IUCN Species Survival Commision. IUCN, Gland, Switzerland and Cambridge, UK. The species is listed as threatened in several Spanish compilatory works on threatened flora, such as `The Spanish Red List of Vascular Flora' and the `Atlas and Red Book of Threatened Vascular Flora of Spain', although it does not figure as such in any Portuguese document. Here we report detailed studies of its distribution, and assess its current conservation status with respect to this, the sizes of its populations, and the threats it faces. Our estimation of the size of the Iberian populations was based on our own census data from those sites at which we found the species. All censuses were performed by direct counting of all potentially reproductive individuals. Fourteen populations were found, and the total members thought to exist are 161, with a highly fragmented distribution on the Spanish–Portuguese border along the valley of the River Duero. Exhaustive bibliographical and field surveys were carried out and herbarium specimens housed in several herbaria were revised in order to determine the Extent of Occurrence and the Area of Occupancy. Based on our data, the species is classifiable as Critically Endangered and Endangered in Portugal and Spain, respectively. The risk of local population extinction is high due to its typically small local population sizes and suitable conservation strategies should be developed in order to preserve the species.  相似文献   

2.
Ferula loscosii (Lange) Willk (Apiaceae) is a threatened endemic species native to the Iberian Peninsula. The plant has a narrow and disjunct distribution in three regions, NE, C and SE Spain. Genetic variability within and among 11 populations from its natural distribution was assessed using allozymes. Intermediate levels of genetic diversity were detected in F. loscosii (P(99%) = 36.83; H(E) = 0.125; H(T) = 0.152). However, the highest genetic diversity (58%) corresponded to the threatened populations from SE and C Spain (H(T) = 0.169) rather than the more abundant and larger populations from NE Spain (Ebro valley) (H(T) = 0.122). Low to moderate levels of genetic structure were found among regional ranges (G(ST) = 0.134), and several statistical spatial correlation analyses corroborated substantial genetic differentiation among the three main regional ranges. However, no significant genetic differentiation was found among the NE Spain populations, except for a northernmost population that is geographically isolated. Outcrossing mating and other biological traits of the species could account for the maintenance of the present values of genetic diversity within populations. The existence of an ancestral late Tertiary wider distribution of the species in SE and C Spain, followed by the maintenance of different Quaternary refugia in these warmer areas, together with a more recent and rapid post-glacial expansion towards NE Spain, are arguments that could explain the low genetic variability and structure found in the Ebro valley and the higher levels of diversity in the southern Iberian populations.  相似文献   

3.
The toxic dinoflagellate Gymnodinium catenatum Graham has formed recurrent toxic blooms in southeastern Tasmanian waters since its discovery in the area in 1986. Current evidence suggests that this species might have been introduced to Tasmania prior to 1973, possibly in cargo vessel ballast water carried from populations in Japan or Spain, followed by recent dispersal to mainland Australia. To examine this hypothesis, cultured strains from G. catenatum populations in Australia, Spain, Portugal, and Japan were examined using allozymes and randomly amplified polymorphic DNA (RAPD). Allozyme screening detected very limited polymorphism and was not useful for population comparisons; however, Australian, Spanish, Portuguese, and Japanese strains showed considerable RAPD diversity, and all strains examined represented unique genotypes. Multidimensional scaling analysis (MDS) of RAPD genetic distances between strains showed clear separation of strains into three nonoverlapping regional clusters: Australia, Japan, and Spain/Portugal. Analysis of genetic distances between strains from the three regional populations indicated that Australian strains were almost equally related to both the Spanish/Portuguese population and the Japanese population. Analysis of molecular variance (AMOVA) found that genetic variation was partitioned mainly within populations (87%) compared to the variation between the regions (8%) and between populations within regions (5%). The potential source population for Tasmania’s introduced G. catenatum remains equivocal; however, strains from the recently discovered mainland Australian population (Port Lincoln, South Australia, 1996) clustered with Tasmanian strains, supporting the notion of a secondary relocation of Tasmanian G. catenatum populations to the mainland via a shipping vector. Geographic and temporal clustering of strains was evident among the Tasmanian strains, indicating that genetic exchange between neighboring estuaries is limited and that Tasmanian G. catenatum blooms are composed of localized, estuary-bound subpopulations.  相似文献   

4.
ABSTRACT

Capsule A combination of several biometric measures enables the reliable sexing of the European Bee-eater Merops apiaster, a species with subtle sex differences in plumage and morphometry.

Aims To explore variation in biometrics and their suitability to discriminate sex in adult European Bee-eaters Merops apiaster.

Methods We sampled populations of a long-distance migratory species with low sexual size dimorphism, the European Bee-eater Merops apiaster, from colonies in western Iberia (Portugal) and Central Europe (Germany) to investigate body size variation and derive population-specific and general sex discriminant functions.

Results Overall, male Bee-eaters were larger than females while Bee-eaters from Germany and Portugal did not differ in size, except for primary length and tail length. The best single measurement to discriminate sex was wing length for Portuguese birds and tail tip length for German birds, as in the combined dataset. Multivariate discriminant functions of head-bill, wing and tail tip lengths provided the highest discriminant accuracy, discriminating sex for 91% of the birds from Portugal, 96% from Germany and 94% when using the combined dataset. Nonetheless, the discriminant accuracy remained high in the functions using only two variables for Portugal (head-bill and tail tip 91%, head-bill and wing 88%, wing and tail tip 88%), Germany (head-bill and tail tip 95%, wing and tail tip 97%) and in the combined dataset (head-bill and tail tip 92%, wing and tail tip 93%).

Conclusions Population specific discriminant functions allow sexing of European Bee-eaters by morphometry with high degree of accuracy at least for Iberia and Central European populations. Such discriminant functions can be used to assign the sex of adult Bee-eaters reliably and swiftly while the bird is still in the hand, highlighting the potential of these functions for rapidly sexing species with low degrees of sexual size and plumage dimorphism.  相似文献   

5.
The present study assessed the existence of variation in the shell shape of the pod razor shell (Ensis siliqua) throughout its distributional range in the north-eastern Atlantic. Shells of E. siliqua caught at seven collecting sites (three in Portugal, three in Spain and one in Ireland) were studied by geometric morphometric methods, using both landmark- and contour-based methods. Both approaches (landmarks inside the valves and shell outline) discriminated the shells from Aveiro (centre of Portugal) and Strangford Lough (Ireland) from those caught in the nearby localities (remaining Portuguese and Spanish sites, maximum distance of 550 km by sea). Landmark analysis revealed that shells from Aveiro were more similar to shells from Ireland (~1,500 km far away). Contour analysis revealed that shells from Aveiro had a shape with a comparatively larger height-to-width ratio, whereas shells from Ireland showed a slightly more curved outline than in the remaining sites. Landmark- and contour-based methods provided coherent complementary information, confirming the usefulness of geometric morphometric analyses for discerning differences in shell shape among populations of E. siliqua. A brief review of previous applications of geometric morphometric methods to modern bivalve species is also provided.  相似文献   

6.
The ruddy duck (Oxyura jamaicensis), a stifftail native to the Americas, was introduced to the UK in the 1950s and has since been recorded in 22 western Palearctic countries. By 2000, the UK population peaked at nearly 6,000 individuals. In 1991, hybridisation with the native and globally threatened (IUCN Endangered) white-headed duck (Oxyura leucocephala), a stifftail restricted to the Mediterranean and Asia, was recorded in Spain and culling of hybrids and ruddy ducks began. Here we report on a series of genetic studies that have enabled and supported management decisions to the benefit of the white-headed duck. First, genetic data confirmed that these are two distinct species, each of which is more closely related to other stifftail species. Second, molecular studies indicated that ruddy ducks in Spain, Iceland and elsewhere in Europe were of captive origin and not descendants from vagrants from their native North America. Third, genetic methods were used to distinguish among different hybrid generations in Spain and detected no ruddy duck introgression in birds identified morphologically as white-headed ducks. Collectively, these results supported management decisions to eradicate ruddy ducks from Europe. Subsequently, a control programme reduced the UK population by over 95 % by 2010, and the arrival of ruddy ducks to Spain decreased from 21 birds in 2003 to two sightings in 2010–2011. However, increased efforts to control small ruddy duck populations elsewhere in Europe and Morocco are still required to ensure conservation of the white-headed duck. This case of invasion by hybridization demonstrates that successful control is feasible given early detection followed by a rapid response plan; it also shows the contribution of research to management and that to guarantee the conservation of an endangered native species action may be required in countries outside its distribution range.  相似文献   

7.
Critically endangered species representing ancient, evolutionarily isolated lineages must be given priority when allocating resources for conservation projects. Sound phylogenetic analyses and divergence time estimations are required to detect them, and studies on their population genetics, ecological requirements and breeding system are needed to understand their evolutionary history and to design efficient conservation strategies. Here we present the paradigmatic case of Avellara, a critically endangered monotypic genus of Compositae inhabiting a few swamps in the west–southwest Iberian coastal plains. Our phylogenetic and dating analyses based on nuclear (ITS) and plastid (matK) DNA sequences support a Miocene (>8.6 Ma) divergence between Avellara and closely related genera, resulting in marked morphological and ecological differentiation. We found alarmingly low levels of genetic diversity, based on AFLPs and plastid DNA sequences, and confirmed the prevalence of clonal reproduction. Species distribution modelling suggested a large macroclimatically suitable area for Avellara in the western Iberian Peninsula, but its apparently narrow microecological requirements restrict its distribution to peatlands with low‐mineralised waters. Although five populations have been recorded from Spain and Portugal in the past, its current distribution may be reduced to only one population, recurrently found in the last decade but threatened by herbivory and habitat degradation. All this confirms the consideration of Avellara as a threatened species with high phylogenetic singularity, and makes it a flagship species for plant conservation in both Spain and Portugal that should be given priority in the design of in situ and ex situ conservation programmes.  相似文献   

8.
Tourism and recreation are large industries employing millions of people and contribute over US$2.01 trillion to the global economy. Unfortunately they also have diverse and sometimes severe environmental impacts affecting many species, including those that are rare and threatened. To assess the extent to which these industries threaten vascular plants, we reviewed data in the IUCN Red List for 462 Critically Endangered, Endangered and Vulnerable European species. Tourism and recreation were listed as threatening 42 % (194 species) of these species from across 50 families, mostly herbs (70 %). They were listed as threatening plants in 9 of the 10 bioregions in Europe and in 25 of the 40 countries assessed. Popular tourism destinations such as the Canary Islands (41 species) and mainland Spain (40 species) had the greatest diversity of species listed as threatened by tourism and recreation. The most common of these threats were trampling (61 species), plant collection (59), the maintenance/construction of tourist infrastructure (43) and habitat degradation due to the urbanisation of tourist sites (13). Additional species assessments and more research on the impacts of tourism and recreation may add to these values. It is clear that these industries pose an important threatening process on plants in Europe based on the IUCN Red List data and hence deserve greater recognition in terms of research, conservation and management.  相似文献   

9.
Abstract

A Red List of all 108 Pezizomycotina (Ascomycota) species recorded in Umbria Region (central Italy) is provided. According to the IUCN categories and criteria, 60.18% of the assessed species are classified as threatened, whereas 12.96% are Near Threatened (NT), 1.86% are Least Concerned (LC) and a noteworthy amount of 25% are Data Deficient (DD). As a consequence of the downlisting applied to the majority of the assessed taxa, according to the guidelines for application of IUCN red list criteria at Regional level, only 1.54% of the threatened species is Critically Endangered (CR), while 46.15% are Endangered (EN) and 52.31% are Vulnerable (VU). Given that the present work represents the first complete regional red list of Pezizomycotina in Italy, and that a national, as well as a European red list do not exist to date, it could be considered as a case study for other Italian Regions as well as for other European countries, aiming at the compilation of a national and European red list of this fungal group mostly overlooked in conservation strategies.  相似文献   

10.
To date, the endangered terrestrial orchid Codonorchis canisioi was only known from two collections at its type locality. This plant has not been collected since 1935 and is currently considered as Critically Endangered in the Brazilian list of threatened flora. We recently found two small populations about 174 km from the type locality. We thus seized the opportunity to make a complete record of morphological traits, aiming to fill the gaps of the short and non-illustrated protologue. Plant, flower (including details of column and pollinarium) and fruit features are here illustrated and discussed in detail. Overall, plant and flower features are similar to those of the widespread Patagonian C. lessonii. Yet, both species can be separated by a number of vegetative and floral features. Female Augochlorine Halictidae bees were recorded as pollinators. Fruits mature quickly (15–19 days after pollination). Plants wither by middle October, resting underground as very small (3–5 mm diameter) roundish tubers. The two newly found populations are in privately owned areas and prone to both fire and cattle grazing. Due to the small size of each population (estimated in less than 200 individuals), it is likely that this species would still be considered as CR (Critically Endangered) when formally and properly surveyed under the IUCN criteria. Since plants are small and strongly seasonal, more field surveys are necessary to locate other potentially overlooked populations.  相似文献   

11.
We evaluated reproductive isolation of Chinook salmon (Oncorhynchus tshawytscha) life history types that have been reintroduced to northern Idaho, USA. Analysis of 1003 samples at six microsatellite loci revealed strong reproductive isolation between ocean- and stream-type Chinook salmon (fall and summer spawn timing, respectively) within the Clearwater River sub-basin (F ST = 0.148, P < 0.00001). Very little evidence for gene flow among the two life history types was observed as assignment tests correctly assigned 99.6% of individuals in reference collections to either ocean- and steam-type Chinook salmon. Assignment of naturally reared juveniles indicated that both life history types were present with 24.1% stream-type and 75.9% ocean-type. Previous studies suggest high levels of divergence among the two life history types in natural populations, and our study verifies the persistence of reproductive isolation among types following colonization of habitat. Successful colonization of new habitat by (re)introduced species is likely influenced by diversity in life history types and this strategy has lead to naturally spawning populations in a variety of available habitats in the Clearwater River. As many populations of O. tshawytscha are listed as threatened or endangered under the U.S. Endangered Species Act, hope for recovery lies not only in effective management and habitat improvement, but adaptability of this species.  相似文献   

12.
Abstract

Assessing the conservation status of endemic species by monitoring population trends is one of the main aims of plant conservation studies. This article reports a detailed study of the distribution of Antirrhinum rothmaleri, a species endemic to the serpentine systems of Trás-os-Montes in NE Portugal (Lusitan-Duriensean biogeographical sector). The species' current distribution status, the size of its populations, and the threats it faces, measured according to International Union for Conservation of Nature (IUCN) 2008 Guidelines, were all assessed. The size estimates provided for the four confirmed populations were based on census data taken at the different sites. All censuses were performed by direct counting of all potentially reproductive individuals. Based on the present data, A. rothmaleri should be assigned a conservation status of “Critically Endangered” (CR). Its conservation status, according to the IUCN criteria, is mainly based on the narrow distribution, and on the area of occupancy (AOO) and extent of occurrence (EOO). The risk of extinction faced by the local populations is high due to their typically very small size. Suitable conservation strategies should be developed in order to preserve the species. The present study allowed us to characterize its distribution and population size, to collect and store ex situ the germplasm in the UIRGEMP/Banco Português de Germoplasma Vegetal, and to investigate its ecology. The conservation status of the species requires continued monitoring of the demography of its populations. Studies on the biology of the species are also needed in order to improve its management. The present results illustrate the need to protect serpentine landscapes, which contain a range of microhabitats inhabited byendemic plants.  相似文献   

13.
The present study aimed at estimating the age and growth in three populations of Dosinia exoleta from the Portuguese coast (Aveiro in the north, Setúbal in the southwest and Faro in the south). Two techniques were compared to ascertain the most suitable method for ageing D. exoleta. Growth marks on the shell surface and acetate peel replicas of sectioned shells were the techniques applied. Two hypotheses were tested: growth parameters present latitudinal variation along the Portuguese coast; growth parameters are influenced by the fishing exploitation. Shell surface rings proved inappropriate for ageing this species, whereas acetate peels provided realistic estimates of the von Bertalanffy growth parameters (K, L and t 0). A latitudinal gradient in growth rate was detected, with a clear southward increase in the growth coefficient (K) of D. exoleta (Faro > Setúbal and Aveiro) indicating that warmer waters in southern Portugal provide optimal conditions for the growth of this species. Fishing exploitation in northern Portugal targets larger individuals and leaves behind a younger population of smaller individuals, decreasing the asymptotic shell length (L ) of D. exoleta from Aveiro. The overall growth performance was compared among populations of D. exoleta and with other venerid species worldwide.  相似文献   

14.
Insular carnivores represent some of the most critically threatened species, but also the least known. To evaluate the conservation status of these species, thorough abundance estimates are urgently required. To better understand the population biology and conservation status of the endemic and threatened pygmy raccoon (Procyon pygmaeus) and dwarf coati (Nasua nelsoni) on Cozumel Island, Mexico, we worked island-wide to identify the presence of these species, and for the pygmy raccoon we studied several populations in depth during 2001–2003. On Cozumel, trapping was conducted for >6,600 trap nights in 19 locations of varying habitat types. A total of 96 pygmy raccoons (47 males and 49 females) and a single adult, male dwarf coati (N. nelsoni) were captured. Estimated total annual pygmy raccoon population size ± SE was 80 ± 26.1, resulting in an average density of 22 ± 5.1 raccoons/km2 for the three small sites where the animals persist. Based in part on the findings of this study that indicate these species have a restricted range and small population numbers, the IUCN recently changed the listing of the pygmy raccoon to Critically Endangered from Endangered. In contrast, the status of the dwarf coati (Endangered) has not been changed, although the taxon is in eminent danger of extinction and in need of immediate conservation action.  相似文献   

15.
Aim Aglaope infausta is a thermophilous Zygaenid of Atlanto-Mediterranean origin, distributed in Portugal, Spain, France and north-western Italy reaching its north-eastern distribution limit in western Germany. The local, regional and inter-regional genetic structure of this species is studied in this analysis. Location and methods The allozymes of 456 individuals from 12 populations (11 from western Germany and one from southern Portugal) were studied by electrophoresis. Results Six of the 19 loci analysed were monomorphic. Genetic differentiation between populations was high (FST: 0.404), while the mean genetic diversity was low (He: 3.4%). Most (96.5%) of the genetic variance between populations was between the Portuguese and the German samples, but also the differentiation within Germany was considerable (FSR: 0.101). In Germany, A. infausta occurs in two major regions (middle Rhine and Nahe) that are geographically separated, and 55.5% of the genetic variance was found between these two regions. The populations of both areas do not differ in their genetic diversity, but those of the middle Rhine have significantly higher genetic distances among them than the Nahe populations (0.020 and 0.015, respectively). FST was also higher in the middle Rhine region than in the Nahe region (0.089 and 0.045, respectively). Main conclusions Aglaope infausta shows a very low level of genetic heterogeneity for a lepidopteran species. However, this genetic poverty is not affecting the species’ viability. During the ice ages, differentiation into two genetic lineages occurred, most probably in a south-western and a south-eastern differentiation centre in Iberia. The gap in the distribution range in Germany is clearly reflected in the genetic structure. This differentiation must have developed relatively quickly because western Germany most probably was colonized during the climatic optimum 6000 years ago.  相似文献   

16.
Human-mediated hybridization poses a serious threat to the genetic integrity of threatened inter-fertile species or subspecies, such as the bontebok (Damaliscus pygargus pygargus) and blesbok (Damaliscus pygargus phillipsi) in South Africa. The identification of pure and admixed populations is key to sound biodiversity conservation management and practices. Where identification based on morphometric measurements are complex, molecular analysis can provide a tool to identify hybrids or introgression in populations. This study provides the first molecular analyses on pure bontebok and blesbok as well as putative hybrid populations and samples of unknown purity. Analysis of a panel of 13 microsatellite markers by applying a Bayesian model-based clustering programme provided evidence of clear partitioning between the two subspecies. Hybridization was detected in 33 % (40 of 121) of the samples with unknown purity. Currently, bontebok is listed as protected under the Convention on International Trade in Endangered Species of Wild Fauna and Flora and is listed as endangered under the United States of America’s Endangered Species Act. Our research found that the microsatellite markers used in this study could accurately identify pure and hybrid animals and can be used as a tool to conserve the genetic integrity of both subspecies.  相似文献   

17.
Endangered species with small and isolated populations has been a key topic of conservation biology studies in the last decade. Lamyropsis microcephala is among the most significant narrow endemic plants in the Mediterranean region, lying on the Gennargentu massif of the Sardinia island (Italy). Due to heavy threat factors, this species has rapidly become threatened with extinction. The inter-simple sequence repeat technique was used to assess the genetic variation and structure of the individuals growing in the four remnant localities known to date, with the aim to implement further conservation strategies. Results indicated a degree of differentiation among the four subpopulations, in particular for the Fonni one. The estimates of Nei's genetic diversity (H) ranged from 0.0563 (Fonni) and 0.1104 (Bau ‘e Laccos). Analysis of molecular variance values showed that 53% of the total variation may be attributed to the individuals within subpopulations, while 47% is due to differences among subpopulations (P < 0.001). Results also highlighted a scarce gene flow (Nm = 0.503).  相似文献   

18.
ABSTRACT

The Portuguese and the European Flora refer to the presence of two or three Azolla species in Portugal: A. filiculoides Lam., A. caroliniana Willd. and/or Azolla mexicana Presl., the latter included in the last edition of Flora Europaea. In the present work, the taxonomy of Azolla species is reviewed using the two most important characters that can distinguish between these two/three species: papillae in the dorsal leaf lobe and perine architecture of the megaspore apparatus. Other characteristics, such as the hyaline border cells of the dorsal leaf lobes and the number of glochidia septa in microsporangium massulae, are also used. All the Azolla specimens, collected from several locations in Portugal, were identified as Azolla filiculoides Lam. This identification disagrees with previous published reports on Azolla taxonomy in Portugal as well as with herbarium identification.  相似文献   

19.
Aim Recent colonization of northern Portuguese shores by Patella rustica Linnaeus, 1758, led to the bridging of a historical gap in the distribution known since the 1900s. Long‐term oceanographic data collected over the last half‐century were examined in order to detect possible mechanisms for the observed change in its distribution. Location This study was carried out along the entire Portuguese coastline, from 41°50′ to 37°06′ N. Time‐series of hydrographical variables (sea surface temperature and salinity) were derived for the Atlantic coast of the Iberian Peninsula. Methods Abundance and size‐frequency distributions of the newly observed limpet populations were compared with those from well‐established populations in southern Portugal. Anomalies were computed for sea surface temperature (1950–2000) and sea surface salinity (1958–2001) data, covering the whole Atlantic coast of the Iberian Peninsula. An upwelling index (1967–2005) was derived for a single location within the distributional gap of P. rustica. Split moving window analysis was performed to detect significant discontinuities in hydrographical data sets. Results Patella rustica has gradually been expanding in northern Iberia, and in the late 1990s the historical gap in distribution in northern Portugal was bridged. Size‐frequency distribution differed between historical and recent populations, the latter lacking small‐sized individuals. At the same time, several anomalous oceanographic events occurred off the Portuguese coast and were probably related to this expansion. Main conclusions Although sea surface temperature might be a major determinant of the reproductive success of P. rustica and hence its dispersal potential, it is more likely that a coincidence of several factors occurring in the late 1990s provided exceptional conditions that allowed the geographical expansion of this species.  相似文献   

20.
ABSTRACT

The present study compared Portuguese and Spanish children in the 6th year of primary school in terms of their knowledge and live experience of animals from the Iberian Peninsula (IP) and the African savannah. A questionnaire was administered to 420 children from state schools, 215 from Portugal and 205 from Spain. The questionnaire included photos of eleven mammals from each region. The pupils had to identify them, to say if they had observed them live and where, and if they are native in the IP. The results showed a greater knowledge of both groups of the savannah species, also the ones most had seen live. However, the Spanish children had a better performance in the identification of the native mammals and which animals are native on IP, probably because these children are from a less urban zone, with more direct contact with some of the species presented. The school does not seem to play, in either group, an important role in the learning about native species. Boys from both countries performed better than girls on the issues under study. A high percentage of children from both countries think that several of the savannah species occur wild on the IP.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号