共查询到20条相似文献,搜索用时 15 毫秒
1.
Hansson 《Ecology letters》1998,1(3):142-145
Nestedness was examined for vascular plants and birds in the centres and edges of 26 sites of ancient oak-hazel woodland in Sweden. Both taxa exhibited significant nestedness in site centres and for whole sites, but not at the edges for birds. Woodland ranks of nestedness differed between plants and birds. Rank of nestedness of birds, but not of plants, depended on area. Horizontal habitat structure affected nestedness of both plants and birds. Mobility appears decisive for creating rank differences between sites for various taxa. High mobility may also explain a greater edge effect in birds from allochtonous, more or less transient individuals. Nestedness in relation to mobility, particularly at edges, should be of theoretical interest. The possible use of nestedness patterns in conservation makes further analyses urgent for less mobile taxa. 相似文献
2.
Wind farms have shown a spectacular growth during the last 10 years. As far as we know, this study is the first where the
relationship between wind power and birds and small mammals have been considered. Before–after control impact (BACI) study
design to birds and Impact Gradient (IG) study design to small mammals to test the null hypothesis of no impact of a wind
farm were used. In the BACI model Windfarm Area and a Reference Area were considered. Distance from turbines was considered
in the IG model. Windfarm installations did not clearly affect bird and small mammal populations. Flight height of nesting
and no nesting birds did not show a clear tendency. Small mammals populations suffered high variations in numbers through
times by intrinsic population factors. There are many practical problems of detection of human influence on abundances of
populations so sampling in the long run can be suggested. 相似文献
3.
We evaluated how the abundance and richness of frugivorous and nectarivorous bat species differs among three types of common agroecosystems (diversified coffee plantations, simple coffee plantations and pastures) in Veracruz, Mexico, that represent a gradient of structural and floristic complexity. Using mixed effects models we demonstrated that both the richness and the total abundance of bats was higher in the diversified coffee plantations. We detected similar patterns on comparing the abundance of the four most abundant bat species. Neither season nor the season-agroecosystem interaction had any effect on the comparisons made. Using multiple regressions we found that the richness of plants that are useful to both people and bats had the most explanatory power for the richness and total abundance of frugivorous and nectarivorous bats, as well as for the abundance of Carollia sowelli, Glossophaga soricina and Sturnira spp. Our results indicate that agroecosystems value for conservation of fruit and nectar-eating bats increases as the fruit-bearing trees increases. For the effective conservation of these guilds of bats in tropical agroecosystems, a strategy of diversification with fruit-bearing species is highly recommended; such a strategy would benefit both agricultural producers and wildlife. 相似文献
4.
Alien plants from psammophilous ecosystems have been studied in southern Spain. Sixteen sites, which are included in the Andalusian Network of Protected Spaces, have been chosen along 1100 km of Andalusian coasts in order to verify the degree of abundance and influence of these species on different communities. Out of the 26 localized species, the increase of some invasive plants, such as Arctotheca calendula, Agave americana, A. sisalana, Cortaderia selloana, Lantana camara and Opuntia dillenii, affects the conservation of some natural coastal ecosystems. 相似文献
5.
ADRIAN G. MARSHALL 《Zoological Journal of the Linnean Society》1985,83(4):351-369
The Megachiroptera, with a single family, 43 genera and 174 species, are confined to the Old World tropics and subtropics where they are exclusively phytophagous, feeding upon floral resources (largely nectar and pollen but also petals and bracts), fruit, leaves and water. A literature survey revealed information on the food sources for only 21 genera of bats, these feeding upon 75 genera of flowers, 145 genera of fruit and 10 genera of leaves in a total of 34 orders, 66 families and 198 genera. The bats are likely to pollinate flowers of at least 31 genera and presumably may disperse the seeds of the majority of fruits consumed. Despite our ignorance about the relationship between Megachiroptera and plants, it appears that most bats are catholic in their choice of food, and most plants are visited by a diversity of bats. 相似文献
6.
Deborah Faria Mateus Luís Barradas Paciencia Marianna Dixo Rudi Ricardo Laps Julio Baumgarten 《Biodiversity and Conservation》2007,16(8):2335-2357
The traditional shade cacao plantations (cabrucas) of southern Bahia, Brazil, are biologically rich habitats, encompassing
many forest-dwelling species. However, a critical question for the conservation management of this specific region, and the
highly fragmented Atlantic forest in general, is to what extent the conservation value of cabrucas relies on the presence
of primary forest habitat in the landscape. We investigated the relative importance of cabrucas and forests for the conservation
of five diverse biological groups (ferns, frogs, lizards, birds and bats) in two contrasting landscapes in southern Bahia,
one dominated by forest with some interspersed cabrucas, and one dominated by cabrucas with interspersed forest fragments.
The community structure (richness, abundance and diversity) of all biological groups differed between cabrucas and forests,
although these differences varied among groups. A high number of forest species was found in the cabrucas. However, there
were pronounced differences between the two landscapes with regard to the ability of cabrucas to maintain species richness.
Irrespective of the biological group considered, cabrucas located in the landscape with few and small forest fragments supported
impoverished assemblages compared to cabrucas located in the landscape with high forest cover. This suggests that a greater
extent of native forest in the landscape positively influences the species richness of cabrucas. In the landscape with few
small forest fragments interspersed into extensive areas of shade cacao plantations, the beta diversity of birds was higher
than in the more forested landscape, suggesting that forest specialist species that rarely ventured into cabrucas were randomly
lost from the fragments. These results stress both the importance and the vulnerability of the small forest patches remaining
in landscapes dominated by shade plantations. They also point to the need to preserve sufficient areas of primary habitat
even in landscapes where land use practices are generally favorable to the conservation of biodiversity. 相似文献
7.
Pleguezuelos JM Santos X Brito JC Parellada X Llorente GA Fahd S 《Zoology (Jena, Germany)》2007,110(1):9-19
Eurosiberian vipers have been considered model organisms, and studies on their reproductive ecology have afforded much of the current knowledge concerning viviparity in snakes. However, such studies are biased towards northern species and there is little information on Mediterranean species and/or populations. The reproductive ecology of Vipera latastei in the Iberian Peninsula was studied by analysing a large sample of specimens from collections, to better understand the conservation status of this Mediterranean viper. Males and females matured at small and similar body sizes (240 and 265 mm snout-vent length, respectively) and reproductive cycles in both sexes were seasonal. Spermatogenesis peaked in August, vitellogenesis developed in spring and the timing of the mating period was puzzling, with populations mating in autumn, spring, or in both seasons. The most striking finding was that adult females reproduced triennially on average. Lataste's viper is currently in continuous decline in the IP, and most of its populations are isolated in Mediterranean mountains. We hypothesize that prey scarcity and the brevity of the activity period in mountain habitats diminishes the ability of vipers to recover over the short term the energy expended in reproduction. The species needs 2 years for the acquisition and storage of energy ("capital breeder"), and a third year for the expenditure of this energy (in vitellogenesis and embryogenesis), a year during which females feed consistently ("income breeder"). Thus, this viper combines both strategies to supply the reproductive energy cost. Current decline in population and distribution, together with a poor capacity to renew populations, renders Lataste's viper vulnerable to environmental stochasticity. 相似文献
8.
《Journal for Nature Conservation》2014,22(2):166-175
Semiarid Mediterranean areas patchily forested with Pinus halepensis Mill. are often affected by urbanisation plans, which influence the conservation of biodiversity in the remaining fragments. We assessed forest biodiversity in eleven Pinus halepensis patches of the municipality of Murcia (SE Spain), on the basis of the abundance, richness and conservation value of birds and woody flora. Under the hypothesis that biodiversity is conditioned by pine density, modulated by other patch features (age, physical substrate, surrounding land uses), mixed regression models were used to relate biodiversity indicators with environmental gradients, detected through principal component analyses (PCAs) performed on three sets of variables: landscape (L); habitat structure (H); and, stand development (S). PCA-L related patch size and connectivity to the abundance of typical woodland birds and to floral and bird species richness. PCA-H related shrub cover associated with Sylvia melanocephala Gmelin., to rock and dry grassland cover, a feature of moderately disturbed areas preferred by Lanius senator L. PCA-S associated taller trees and better physical conditions with canopy dwelling and soil probing bird species, respectively. The bird or plant conservation value of patches did not generally match their protection status, which was confirmed by the analysis of a larger sample of 36 natural patches. A negative relationship between floristic value and pine density suggests that reducing the density of reforestations can lead to more diverse and self-sustaining wooded formations. In contrast, conservation value for birds did not decrease with reforestation, stressing the need to use ornithological and floristic indexes as complementary assessment tools. The results seem useful for building a municipal network of reserves connecting higher status protected areas. 相似文献
9.
Documenting the basic patterns of biodiversity and accurately determining the priority areas are the first steps for conservation studies. Threatened species and IUCN (International Union for Conservation of Nature) Red Lists are among the widely used tools to identify protected areas. Turkey is one of the most important biodiversity centres in the world. The plant diversity of Turkey with over 30% endemic species of approximately 12000 natural vascular plant taxa is well documented through use of a Grid System. However, Turkey has suffered heavy anthropogenic effects having been a settlement for many civilisations throughout the history of humankind. Therefore, Turkey needs a quantitative evaluation of the importance of different grid squares for conserving plant diversity. This paper offers a quantitative approach for aiding the identification of priority areas for biodiversity conservation by analysing the threatened plants in each grid square in terms of endemism, risk categories and distribution characteristics. The grid squares (nearly 220 x 170 km2) were then classified within four different groups in terms of their conservation importance. This national-level information can be used for further research and decision-making processes for conservation planning. 相似文献
10.
Identifying the most noxious invasive plants in China: role of geographical origin, life form and means of introduction 总被引:1,自引:0,他引:1
Qiao Q. Huang Jian M. Wu Yan Y. Bai L. Zhou Gen X. Wang 《Biodiversity and Conservation》2009,18(2):305-316
In a heterogenous world, invasive plants often differ in noxiousness and nature of impacts, and there is a difference between
strong and weak invaders. That knowing which invaders are most noxious and their nature of impacts is of great value to invasive
ecology and management. Here we show that in China the most notorious invasive plants are with a perennial life cycle, clonal
growth ability and from the American continent. They often form monocultural populations in land and water, replacing almost
all other plants, and are mainly distributed in Central and South China. Following are some accidentally introduced annuals.
Annuals from the American continent are often common, dominant or in monocultural populations in ruderal and agricultural
habitats whereas those from Eurasia are highly noxious only in agricultural habitats. Annuals are not restricted in distribution
and could spread fast to all of the country. There are also two perennial grasses from Europe and Mediterranean area and four
intentionally introduced annuals from South America that were identified in this study. Factors that may account for these
patterns include relatedness between invasives and natives, vegetative propagation, and plant strategies. The invasive plants
identified in this study have caused significant negative impacts to native biodiversity, environment, economics and agriculture,
with different groups being different in their extent and nature of impacts. 相似文献
11.
The role of alien plants in the natural coastal vegetation in central-northern Spain 总被引:2,自引:0,他引:2
Juan Antonio Campos Mercedes Herrera Idoia Biurrun Javier Loidi 《Biodiversity and Conservation》2004,13(12):2275-2293
Alien plants in coastal habitats and their influence on natural vegetation are studied. After 5 years working on this subject in the Basque Country and surrounding areas, a number of results from the coastal ecosystems are presented. These ecosystems are one of the most threatened and affected by the invasion of alien plants, especially shore dunes, saltmarshes and cliffs. These kinds of habitats, especially the dunes, experience significant pressure from human activities which favours the expansion of some of these species: Arctotheca calendula, Sporobolus indicus and Oenothera spp. The presence and abundance of these invasive plants and others such as Baccharis halimifolia, Cortaderia selloana, Spartina patens and Carpobrotus edulis in the plant communities in an area between the French border and the western part of the region of Cantabria have been studied. The degree of invasion of each plant in each syntaxonomic unit has been analysed. 相似文献
12.
Jorge Cassinello Emmanuel Serrano Gustau Calabuig Jesús M. Pérez 《Biodiversity and Conservation》2004,13(5):851-866
Evidence of aoudad Ammotragus lervia expansion in the southeastern quarter of the Iberian Peninsula is provided based on recent field surveys. Aoudad has become common in a limited region of the southeast of Spain since its introduction as a game species in Sierra Espuña Natural Park in 1970. Its adaptability enabled it to colonise nearby areas in a short period. Apart from this source of expansion, the increasing number of aoudads in Spanish private game reserves provided other centres of dispersion. In addition, aoudads were introduced on La Palma Island (Canary Islands), becoming a serious threat to endemic flora. Of great conservation concern is the species' potential as a competitor against native ungulates inhabiting the peninsula. Surveys conducted in southern Spain documented rapid colonization of new areas and established viable populations, consisting of adult males and females and the unequivocal presence of nursery groups, in the provinces of Alicante, Almería, Granada and Murcia. Also, aoudads have spread throughout the north and centre of La Palma. There are two main conservational concerns: the necessity of conducting detailed and reliable surveys in all potential regions where the species might expand, and the urgent need of changing current game policies in order to establish reliable controls on big game reserves to prevent animals from escaping. 相似文献
13.
The interaction between birds and wind turbines is an important factor to consider when a wind farm is constructed. A wind farm and two control areas were studied in Tarifa (Andalusia Province, southern Spain, 30STF590000–30STE610950). Variables were studied along linear transects in each area and observations of flight were also recorded from fixed points in the wind farm. The main purpose of our research was to determine the impact and the degree of flight behavioural change in birds flights resulting from a wind farm. Soaring birds can detect the presence of the turbines because they change their flight direction when they fly near the turbines and their abundance did not seem to be affected. This is also supported by the low amount of dead birds we found in the whole study period in the wind farm area. More studies will be necessary after and before the construction of wind farms to assess changes in passerine populations. Windfarms do not appear to be more detrimental to birds than other man-made structures. 相似文献
14.
Destruction and fragmentation of tropical rain forest result in a loss of species and of generating capacity of the ecosystem via animal vectors such as seed dispersal agents. To gather quantitative data regarding this ecological problem, birds and mammals were censused in 30 forest fragments, 15 agricultural islands representing five types of vegetation (coffee, cacao, citrus, pepper and mixed-crops) and in three pastures in Los Tuxtlas, southern Veracruz, Mexico. More than 6000 animals of 257 species were detected thus suggesting the existence of a rich species pool in the fragmented landscape. Frugivores accounted for 60% of species, for 72% of individuals censured and for 85% of the total animal biomass recorded. Clusters of small forest fragments (<100 ha) were richer in species and individuals than clusters of large area (>100 ha) forest islands. Pastures were especially poor in forest birds and mammals. While the agricultural islands studied contributed to only 1% of the total area of vegetation sampled, they contained 58% of all species detected and 34% of all individual birds and mammals censured. Recaptures indicated inter-island movements of forest birds and mammals. Forty percent of the species were detected in forest habitats only, the rest were detected in forest and in agricultural habitats. Seeds of forest interior plants dispersed by birds and bats were detected in the agricultural habitats. The value of agricultural islands as landscape features providing some degree of biotic connectivity among fragmented animal populations is discussed. 相似文献
15.
Characteristics and conservation priority of threatened plants in the Yangtze valley 总被引:1,自引:0,他引:1
Z. Xie 《Biodiversity and Conservation》2003,12(1):65-72
One hundred and twenty-seven threatened species listed in the ChinaPlant Red Data Book were found in the Yangtze valley. One-third of them belongedto four families with high economic value, including Pinaceae, Magnoliaceae,Lauraceae and Ranuculaceae. Of all the plants, 66.9% grew in forests and 71.7%were threatened with damage to habitats. The threatened plants in the studiedregion formed a geographical pattern with two large and six small distributioncenters. The two large centers were in the high mountains in western Sichuan andnorthern Yunnan or around the Sichuan Basin. The six small centers were situatedin fragmented montane forests in the eastern part of the Yangtze valley. Todetermine a plant's threat category, the number of populations 10 wasused as the basic criterion as accorded with the China Plant Red Data Book. Thethreatened plants in the valley could be divided into five ranks of priority forconservation. The plants in the first rank comprised eight species endemic tothe valley, with only one population, which should be first preserved. It wasconcluded that human activity was the main factor threatening the survival ofplants, and protecting forests had been the most effective approach in savingthe threatened plants in the valley. 相似文献
16.
星斗山国家级自然保护区国家重点保护野生植物优先保护定量研究 总被引:7,自引:0,他引:7
在野外调查的基础上,运用濒危系数、遗传价值系数和物种价值系数对星斗山自然保护区33种国家保护植物的优先保护顺序进行定量分析。结果表明属一级保护的有银杏、水杉、伯乐树、珙桐、光叶珙桐、台湾杉和水青树共7种,占21%;属二级保护的有红豆杉、南方红豆杉、蓖子三尖杉、大果青杄、金钱松、黄杉、榧树、连香树、闽楠、楠木、花榈木、鹅掌楸、峨眉含笑、红椿、毛红椿和川黄檗共16种,占49%;属三级保护的有莼菜、金毛狗、红豆树、厚朴、凹叶厚朴、香果树和榉树7种,占21%;属四级保护的有樟树、野大豆和金荞麦共3种,占9%。并提出了加强重点保护野生植物的保护措施。 相似文献
17.
Pleistocene human remains and conservation treatments: the case of a mandible from Atapuerca (Spain)
López-Polín L Ollé A Cáceres I Carbonell E Bermúdez de Castro JM 《Journal of human evolution》2008,54(5):539-545
Research on human evolution depends in many cases on the study of fossil remains that have been treated by conservators. Conservation is a discipline with its own principles and methods. Its goal is not only long-term preservation, but also information recovery and the facilitation of research. Therefore, specialists in conservation propose and carry out the interventions, while research requirements must act as a guide in many steps of the process. In this article, we present an example of a strict conservation methodology applied to a human mandible from the Pleistocene site of Gran Dolina (Sierra de Atapuerca, Spain). An extensive diagnostic examination before the intervention included a computer tomography (CT) scan and stereoscopic light microscopy. This paper describes both the intervention and the mechanical preparation in detail. Finally, the intervention is discussed, as well as general conservation techniques. The compiled details show how this interdisciplinary work allowed retention of both the integrity of the specimen and its information. In conclusion, the development of a suitable method of conservation requires collaboration among all the specialists involved in the study of fossil remains. 相似文献
18.
In order to understand the particular challenges that medicinal plant conservation and management raise at the global level, it is necessary to address issues pertaining their distribution and the environments where they grow. When reviewing medicinal plant studies from eight countries in four regions we found that a high proportion of the reported medicinal plants had wide distributions across countries and continents. Most plants are found wild (40.5%) or naturalized (33.9%), while only 3.3% are cultivated. Since many species are distributed in wild conditions, cultivated and naturalized in several continents, conservation and management interventions would be best served through collaboration between host countries. 相似文献
19.
Diversity, abundance or rare species as a target for the conservation of mammalian carnivores: a case study in Southern Spain 总被引:4,自引:2,他引:4
Alejandro Travaini Miguel Delibes Pablo Ferreras Francisco Palomares 《Biodiversity and Conservation》1997,6(4):529-535
Management goals in protected areas and/or communities usually include diversity as one of the most valuable and confident criteria. Nevertheless, the use of diversity and related indices as a means of evaluating successful management practices could produce conflicting results. Here we report a case study in one of the most important European protected areas. After 6 years of intensive conservation management of the Don~ana National Park, the general abundance and numbers of the target single-species conservation plan (the Iberian lynx) increased, although carnivore community diversity and evenness decreased. This was a result of a disproportionate increase of an oportunistic native species, the red fox. We propose the combined use of diversity, richness and evenness indices when monitoring management practices such as those reported here. 相似文献
20.
Currently 177 vascular plant species are known or presumed to be obligately associated with water in Peru. Their composition and diversity were surveyed in relationship to their distributions among the natural regions of Peru. Despite considerable aridity, the coastal plains of Peru have important aquatic ecosystems, including marshes in river deltas and mangroves in the far north, near the border with Ecuador; 70 species of aquatic plants are found in this coastal region. The Andean highlands include a great variety of wetlands, plus lakes and rivers; 62 species are found, including eight species of Isoetes, some of which are potentially threatened by extinction. The Amazon region of Peru includes both steep montane rivers in the headwaters and wide floodplains formed by meandering rivers in the lowlands; 102 species are found distributed among these ecosystems, although many additional species are semi-aquatic. Research and conservation strategies for Peru's aquatic plants need to take into account these important regional differences. 相似文献