共查询到20条相似文献,搜索用时 15 毫秒
1.
Mexican cloud forest vegetation has been recorded in temperate humidconditions at rather different elevations ranging from 600 to 3000m. They are characterised by high biodiversity under continuousfoggy situations. Some authors state that many genera are quantitativelyimportant to depict cloud forest conditions. Detailed quantitative studiescomprising most of the localities of Mexican cloud forests to depict altidudinaldistribution ranges on basis of preferential genera have not been previouslyconducted. The aim of this study is (1) to recognise characteristic preferentialgenera of Mexican cloud forest conditions, and (2) to determine quantitativelythe current altitudinal distribution pattern of this vegetation type. From adatabase composed by 995 genera inhabiting in the Mexican cloud forests, sixgenera were chosen preliminary as preferential characteristics. These wereClethra, Magnolia, Meliosma, Styrax, Symplocos, andTernstroemia. These genera include 70 species that occur atover 70% of the current Mexican cloud forest fragments. The mean elevation ofthese genera records were 1853 m (±600 at 95% confidenceinterval). The results showed that Mexican cloud forests occur optimally between1250 and 2450 m. Additionally, Mexican cloud forest is the bestdistributed within some provinces of the Región Mesoamericana deMontaña, chiefly at Serranías Meridionales,Sierra Madre Oriental, and SerraníasTransístmicas. The results are discussed in light of theimportance of these regions as diversification centres. 相似文献
2.
Geographic distribution patterns and status assessment of threatened plants in China 总被引:1,自引:0,他引:1
Large scale heterogeneous distribution of biodiversity has become a hot topic for ecologists and conservationists. A threat
status assessment combined with geographic distribution patterns of threatened plants in China has been conducted at a national
scale in this study based upon a distribution database that refers to both specimen records and published references. Currently,
302 threatened plant species are cataloged in the “National Protected Key Wild Plants” in China belonging to 92 families and
194 genera. Results of the assessment according to the Categories and Criteria system of The World Conservation Union (IUCN)
Red List indicate that three species have been assessed as Extinct in Wild (EW) while a further 79, 99 and 112 species have
been assessed as Critically Endangered (CR), Endangered (EN), and Vulnerable (VU), respectively. Distribution patterns of
threatened plants were analyzed with GIS to identify areas of high species diversity. It was found that threatened plant species
occur unevenly within counties and are concentrated in the following eight hotspots: the central and southern Hengduanshan
mountain area; the southeast regions of Yunnan as well as Xishuangbanna and southwestern Guangxi; the southern Hainan island;
the border mountainous regions of Guizhou, Hunan and Guangxi provinces; the mountainous regions of southwestern Hubei and
northern Hunan; southwestern Zhejiang and western Fujian; central Sichuan and southern Gansu; and the western mountains of
Guangdong. Moreover, the 12 counties with the greatest number of threatened plant species represent cumulatively more than
50% of the total listed species and, therefore, are the regions in China that should be prioritized for conservation efforts.
By overlapping the map of threatened plant species with the distribution of national nature reserves, a gap was identified
in protected areas. This research will ultimately provide insights for prioritizing biodiversity conservation as well as processing
the mechanisms of distribution patterns. 相似文献
3.
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
4.
An analysis of the distribution patterns of 124 Mexican gymnosperm species was undertaken, in order to detect the Mexican
areas with high species richness and endemism, and with this information to propose areas for conservation. Our study includes
an analysis of species richness, endemism and distributional patterns of Mexican species of gymnosperms based on three different
area units (states, biogeographic provinces and grid-cells of 1° × 1° latitude/longitude). The richest areas in species and
endemism do not coincide; in this way, the Sierra Madre Oriental province, the state of Veracruz and a grid-cell located in
the state of Oaxaca were the areas with the highest number of species, whereas the Golfo de México province, the state of
Chiapas and a grid-cell located in this state were the richest areas in endemic species. A weighted endemism and corrected
weighted endemism indices were calculated, and those grid-cells with high values in both indices and with high species richness
were considered as hotspots; these grid-cells are mainly located in Southern and Central Mexico. 相似文献
5.
Nepenthes lavicola Wistuba & Rischer (Nepenthaceae) is a pitcher plant endemic to the northern tip of Sumatra Island, Indonesia. Due to its narrow geographic distribution and threats from a volcanic eruption and illegal harvesting by pitcher plant hunters, N. lavicola was assessed as Critically Endangered (CR) under criteria B1 + 2c of the IUCN Red List in 2000. Here, we report two new additional locations of N. lavicola in Aceh Tengah Regency, along with the population data and habitat characteristics of the species in each location. Based on our findings, we propose Endangered (EN) B1ab(iii) + 2ab(iii),C2a(i) as the new conservation status of N. lavicola. The new proposed status has a lower category of threat than the current status of the species. Nevertheless, under the new category, N. lavicola is still considered to be facing a very high risk of extinction in the wild. Comprehensive and immediate conservation actions are required to halt the species from extinction. 相似文献
6.
Raquel Alonso-Redondo Elena De Paz Eduardo Alonso-Herrero Marta-Eva García-González Estrella Alfaro-Saiz 《Journal for Nature Conservation》2013,21(6):414-422
This paper reports on a proposed method for evaluating threat categories for regional flora, based mainly on phytogeographical data. The method involves the creation of current distribution maps, analysis of threat factors and use of the RAMAS Red List software to facilitate rapid and objective classification of taxa in accordance with 2001 IUCN criteria. In order to ensure a more objective approach by the assessor and reduce the range of uncertainty, an index was created for calculating Risk Tolerance (RT) that enabled adjustment of the results obtained and thus supplemented the software used. For trial purposes, the proposed model was applied to Spanish gypsophilous flora currently protected under Spanish regional legislation. When classified using the new model, the taxa in question were placed in very different categories, ranging from least concern (LC) to endangered (EN), indicating the need to redefine both their current legal status and recommended management measures. Use of this method will enable scientists to optimise available information on the geographical distribution of endangered taxa, and help governments both to optimise their financial investment in conservation and to define their priorities. The authors endorse the use of IUCN categories in legal protection texts, and advocate as essential a greater degree of coordination between scientists and governments. 相似文献
7.
Abstract. In order to stress successes in restoration and conservation of species, regionally, nationally or globally, a new instrument has been developed, the ‘Blue Lists’, ‘registers of those Red List species that show a durable overall stabilization or increase of abundance in the region (nation, world) considered’. ‘Blue Data Books’ include additional information on the ecology, conservation, and promotion of the species. For describing the overall change of abundance of every individual species six categories are defined. Furthermore, the effects of nature conservation techniques (NCT) on a species are evaluated using six additional categories. In a test area of 3 431 km2 in northern Switzerland, information was compiled on the change in abundance of the 708 Red List species of higher plants (spermatophyta) over the last 10-15 yr. Overall, 33% of these species showed a stabilization or even increase in abundance; these are Blue List species; ca.20% showed a decline and for almost 50% the change in abundance is not known. NCTs have been successfully applied to more than 50 % of all the species, at least locally. For about a further 30%, the required NCTs are known but have not yet been tried out. If these techniques were applied on a large scale, the decline of very many species in the test area could be stopped. 相似文献
8.
9.
The distribution, habitat and conservation requirements of an endangered stag beetle, Lissotes latidens (Coleoptera: Lucanidae), in south-east Tasmania were investigated. This study trebled the known range of the species to 280 km2, of which 15% constituted potential habitat. The beetle was found to inhabit a range of wet forest types including damp eucalypt forest, wet eucalypt forest, rainforest and riparian areas amongst drier forest types. Relative to other Tasmanian lucanids, L. latidens was found to occur at quite low population densities. The species had a preference for forest with a well-developed overstorey and greater than 10% ground cover of coarse woody debris (CWD). Although L. latidens is soil-dwelling throughout its life-cycle, it has a close association with CWD, occurring under logs at the interface of soil and CWD. Suitable forest habitat for L. latidens is poorly reserved, with 48% managed under clearfell, burn and sow forestry regimes; a practice that is likely to lead to the depletion of CWD over successive harvesting rotations. Recommendations are made for the conservation management of habitat utilised by L. latidens in off-reserve areas. The need for conservation strategies to incorporate the temporal dynamics of habitat important to forest-dependent threatened species is discussed. 相似文献
10.
Patricia Delgado Luís Enrique Eguiarte Francisco Molina-Freaner Elena R. Alvarez-Buylla Daniel Piñero 《Biodiversity and Conservation》2008,17(1):121-137
Phylogenetic, genetic and demographic information are key issues for establishing priorities for conservation. In this study
we explored the Vane-Wrigth measure of phylogenetic diversity for establishing criteria for conservation, when intra as well
as interpopulation level demographic (population size) and genetic (heterozygosity, inbreeding and genetic distances among
populations) parameters are taken into consideration. The data were standardized and analyzed independently and integratively
enabling the calculation of indices or criteria for conservation priorities. We illustrate the application of this approach
in populations of four Mexican pine species that have been considered rare and endangered, Pinus rzedowzkii, P. pinceana, P. lagunae and P. muricata. The application of several independent diversity indices did not allow us to resolve prioritization. However, the integration
of all indices generated different values of importance to conservation, and suggested that the populations with the highest
priorities for conservation are: two for Pinus rzedowskii, P. pinceana, and P. lagunae, and one for P. muricata. These populations have intermediate sizes, are the most divergent in the phylogeny and contain genetic variation that is
representative of the gene pool of each species. Finally, we demonstrated the functionality of some genetic and demographic
parameters; the genetic structure, recruitment rate, geographic distribution and demographic stochasticity, as complementary
indicators for evaluating the conservation priority among populations and species. 相似文献
11.
Isolda Luna Vega Othn Alcntara Ayala JuaN. J. Morrone David Espinosa Organista 《Diversity & distributions》2000,6(3):137-143
Abstract . A track analysis based on the distributional patterns of 967 species of vascular plant taxa (gymnosperms, angiosperms and pteridophytes) was performed to assess conservation priorities for cloud forests in the state of Hidalgo, Mexico, ranged in the municipalities of Chapulhuacán, Eloxochitlán, Molocotlán, Pisaflores, Tenango de Doria, Tlahuelompa and Tlanchinol, as well as five floristically equivalent areas in the states of Veracruz (Teocelo and Helechales), Tamaulipas (Gómez Farías), Morelos‐México (Ocuilan) and Oaxaca (Huautla de Jiménez). In order to detect generalized tracks we employed a new parsimony method, where clades (considered equivalent to generalized tracks) are defined forbidding homoplasy and acting like a compatibility algorithm. Several generalized tracks were found connecting these areas. Cloud forests of Chapulhuacán were connected according to three different generalized tracks and thus have a higher value, qualifying as a priority area for the conservation of cloud forests in the state of Hidalgo. 相似文献
12.
Jean-Philippe Puyravaud Priya Davidar Jean-Pierre Pascal B.R. Ramesh 《Biodiversity and Conservation》2003,12(10):2091-2106
The Red Data Book of Indian Plants (RDB) is a reference manual that lists threatened angiosperms, gymnosperms and pterydophytes. Because it is widely used as an analytical tool and is a major reference for impact assessments on vegetation, it is important that the RDB be as comprehensive and up to date as possible. This study is an attempt to cross-check the listings in the RDB using vegetation inventories and another reference manual, the Atlas of Endemics of the Western Ghats, India []. Field inventories across the Western Ghats gave an estimate of the species relative abundances and the Atlas provided quantitative information on the number of records for the endemic species in herbaria, literature, and during field surveys. The results of this analysis indicate that the RDB and the Atlas agree statistically regarding the conservation status of endemic trees. However, the proportion of threatened species per Atlas record category behaves erratically, indicating that some threatened endemic trees are not listed in the RDB. Our results suggest that the status of threatened plant species should be reexamined on a priority basis using quantitative methodology. An updating of the RDB is urgently needed, particularly for the endemic plants of the Western Ghats. We provide a list of species that are likely to be threatened, yet are not listed. 相似文献
13.
Isolda Luna Vega Othón Alcántara Ayala David Espinosa Organista Juan J. Morrone 《Journal of Biogeography》1999,26(6):1299-1305
Mexican cloud forests, situated between 600 and 3000 m of elevation, exhibit a remarkable high biotic diversity. They follow a fragmented pattern, similar to that of an archipelago, that makes them suitable to vicariance modelling. A Parsimony Analysis of Endemicity (PAE) was applied to the presence/absence of 1267 species of vascular plants (gymnosperms, angiosperms, and pteridophytes) from twenty-four patches of Mexican cloud forests, in order to postulate a preliminary hypothesis of relationships. The single cladogram obtained grouped the twenty-four cloud forests into five clades. These results indicate that the Sierra Madre Oriental, Sierra Madre del Sur, and Serranías Meridionales floristic provinces do not represent natural units. A preliminary vicariance model is presented to explain the sequence of fragmentation of the Mexican cloud forests. 相似文献
14.
The flora of the Pitcairn Islands consists of 81 species, of which 10 are endemic. IUCN Red List threat categories show that over 60% of the indigenous flora is threatened within the island, and over 20% is threatened globally. To provide a more objective regional assessment that could prioritise conservation management, a system of threat scores was applied to each taxon based on potential threat due to habitat damage or exploitation. The main threats affecting the flora and vegetation are posed by habitat clearance, spread of invasive species, small population sizes or restricted distributions, erosion, lack of a frugivorous bird and exploitation. Addressing these threats by means of a system of nature reserves, species-specific recovery plans and control of invasive species, erosion and exploitation, will start to combat these problems. However, any conservation activities must be implemented in conjunction with the interests of the local community, and in consultation with them, in order to ensure success. 相似文献
15.
IUCN濒危物种红色名录与国家濒危物种红色名录都是物种灭绝风险的测度, 前者是全球性评估, 后者则是国别研究。IUCN濒危物种红色名录预警了全球物种的濒危状况, 为全球生物多样性研究提供了大数据; 国别红色名录确定了各国物种受威胁状况, 填补了前者的知识空缺, 两份名录互为补充。目前对国家濒危物种红色名录重视不够。基于如下原因, 应当重视国别濒危物种红色名录的意义: (1)国家是濒危物种保护的行为主体, 物种在一个国家的生存状况是确定其保护级别、开展濒危物种保育的依据; (2)对于仅分布于一个国家的特有物种来说, 其国别濒危物种红色名录等级即是其全球濒危等级; (3)对于跨国境分布的物种来说, 国别濒危物种红色名录等级则确定了该物种在本国的生存状况; (4)结合IUCN濒危物种红色名录, 国别濒危物种红色名录为建立跨国保护地、保护迁徙物种的栖息地与跨国迁徙洄游通道提供依据; (5)国别濒危物种红色名录所特有的“区域灭绝”等级, 反映了一个物种边缘种群在该国的区域灭绝, 恢复“区域灭绝”物种是该物种原分布国重引入保育工作的重点; (6)国别濒危物种红色名录提供了该国物种编目、分类、分布和生存状况的最新信息。然而, 国别濒危物种红色名录的重要性在许多情况下被忽视了。目前正值全球新冠肺炎大流行, 人们正在重新审视人与野生动物的关系。我国将修订有关野生动物保护与防疫法法律以及《国家重点保护野生动物名录》, 防控新的人与野生动物共患疾病再次暴发。对于确定国家重点保护野生动物物种名录来言, 物种受威胁程度是物种列为国家重点保护物种的特征之一。重视国别红色名录有特别的意义。 相似文献
16.
We related pteridophytes versus tree species composition to identify surrogate measures of diversity, and complementarity of seven cloud forest fragments. Forest structure, and fern and tree composition were determined in 70 (2 × 50 m) transects. Fern density (10,150–25,080 individuals/ha) differed among sites. We recorded 83 fern species in the transects. Nonparametric richness estimators indicated that more sampling effort was needed to complete fern inventories (14 more species). However, ferns recorded outside of the transects increased richness to 103 species (six more species than predicted). Twenty-eight species were unique and rare due to special habitat requirements (Diplazium expansum, Hymenophyllum hirsutum, Melpomene leptostoma, Terpsichore asplenifolia), or were at a geographical distribution edge (Diplazium plantaginifolium, Lycopodium thyoides, Pecluma consimilis, Polypodium puberulum). Correlations between fern richness and tree richness and density were not significant, but were significant between fern richness and fern density, between epiphytic fern density and tree richness and density. Tree richness is not a good surrogate for fern diversity. Only three species were recorded in all fragments (Polypodium lepidotrichum, P. longepinnulatum, P. plebeium); thus fragments pteridophytes compositions are highly complementary, but more similar for ferns than for trees. A regional conservation approach which includes many small reserves needs to focus supplementarity on patterns of tree and fern species richness. 相似文献
17.
The Global Strategy for Plant Conservation calls for a preliminary assessment of the conservation status of all known plant
species by the year 2010. To date insufficient progress has been made on meeting this target. New efforts to develop a preliminary
list beyond using the full IUCN criteria in plant assessments are needed. Here we present an algorithm that provides a preliminary
assessment of the conservation status of plant species using data from herbarium specimens. We use Hawaiian specimen data
from the United States National Herbarium to calibrate the parameters of the algorithm and then use specimen data from the
Arecaceae, Commelinaceae, Gesneriaceae and Heliconiaceae as examples of the application of the algorithm. The algorithm was
calibrated to insure 95% accuracy in placing the Hawaiian plant species into previously and independently determined threatened
categories. Our results indicate that 28% of the Hawaiian taxa, 27% of the species of Arecaceae, 45% of the species of Commelinaceae,
32% of the species of Gesneriaceae, and 35% of the species of Heliconiaceae are Not
Threatened and will not need any further evaluation for the preliminary assessment. Species identified here as Potentially Extinct and Potentially Threatened can be further assessed by additional herbarium material and/or conservation specialists for final evaluation using other
assessment strategies (e.g., regional and national lists, taxonomic expert assessment, etc.). 相似文献
18.
GO¨RAN Thor 《Biodiversity and Conservation》1997,7(1):59-72
The three major threats to lichens in Sweden; forestry, air pollution, and structural changes in the agricultural landscape, are outlined. Forestry is the most serious. The majority of the red-listed lichens in forests are found in productive forests with a continuity in tree growth, but nearly 70% of the protected area in Sweden consists of alpine landscapes. Examples of important habitats with red-listed lichens are described, e.g. Alnus glutinosa marshes, alvar-vegetation, broad-leaved deciduous forests and different Picea abies forests. The use of selected indicator species of lichens and macrofungi (mainly red-listed species) in boreal coniferous forests provides information on continuity in tree growth of an area, and on earlier influences of forestry. Examples of indicator species for different types of forest are presented and discussed. In spite of the Swedish right of common accesso, collecting of lichens is forbidden without permission from the land-owner. Collecting in protected areas is allowed only with a permit obtained from the authorities. 相似文献
19.
Background
One of the main obstacles for the mainstreaming of religious traditions as tools for the conservation of nature is the limited applicability of research results in this field. We documented two different restrictions implemented by local people (taboos and sacrifices) related to the use of ritual plants in Benin (West Africa) and Gabon (Central Africa).Methods
To see whether these restrictions reflected plant scarcity from an etic perspective (official threat status) and an emic viewpoint (perceived scarcity by local people), we conducted 102 interviews with traditional healers and adepts of traditional faiths.Results
We documented a total of 618 ritual plants, from which 52 species were used in both countries. In Benin, the use of 63 of the 414 ritual plant species was restricted; while in Gabon 23 of the 256 ritual plants were associated with taboos and sacrifices. In Benin, restricted plants were significantly more often officially threatened, perceived as scarce, and actively protected than non-restricted plants. In the more forested and less densely populated Gabon, plants that were perceived as scarce were more often associated to local restrictions than officially threatened species.Conclusions
These results prove the presence of a form of adaptive management where restrictions are related to resource scarcity and protection of ritual plant species. By providing baseline data on possibly endangered species, we demonstrate how plant use in the context of religious traditions can yield important information for conservation planning.Electronic supplementary material
The online version of this article (doi:10.1186/1746-4269-11-5) contains supplementary material, which is available to authorized users. 相似文献20.
Habitat use,density, and conservation status of the white-browed guan (Penelope jacucaca Spix, 1825)
The white-browed guan (Cracidae: Penelope jacucaca) is an endemic bird species to the Caatinga, the largest centre of dry forest in South America. This taxon was considered Vulnerable by the International Union for Conservation of Nature (IUCN) due to continued habitat loss within its distribution and intense hunting pressure that contributed to population declines. However, information on population aspects and habitat use by P. jacucaca, which is fundamental for monitoring its conservation status, is not available. We studied habitat use (analysed in a Generalized Linear Model) and population density (estimated by distance sampling) in a specific area in Northeast Brazil. Using species distribution modelling (SDM), forest cover loss data (performed in the MaxEnt program) and quantitative information about hunting, more rigorous estimates of the distribution limits, available habitat, and population declines of P. jacucaca were generated. Based on the IUCN criteria, we applied analysed data to reassess the conservation status of the white-browed guan. Local density was estimated at 13.1 individuals/km2 and the estimated number of individuals removed per year due to hunting was 121.7 in the forest cover area (110.46 km2) of the Serra de Santa Catarina. Consequently, the annual removal rate of hunted individuals in the study area corresponds to approximately 11% of the population. The habitat use analysis pointed to a strong positive association with seasonally dry deciduous forest (SDDF) vegetation and with arboreal vegetation. The SDM indicated a potential distribution (climatically favourable) area of 675,823 km2, and forest cover and loss calculations indicated a total of 81,307 km2 of available suitable habitat in 2013. Therefore, comparing these results to the IUCN criteria, we recommend that P. jacucaca remain in the Vulnerable category. 相似文献