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Because the conservation of biodiversity occurs under time and resource constraints, it is necessary to prioritize species most deserving of attention. Natural history collections have been identified as a valuable source of information in applied conservation practice, particularly for species-rich taxa like plants. Here, online herbarium information was combined with a novel, straightforward priority setting approach to screen a large list of rare vascular plant species (n = 418) in Saskatchewan, Canada. Data was quantified to develop priority scores (for a given species) using three key criteria: (1) provincial responsibility in species survival, (2) species local population characteristics, and (3) the anthropogenic threats causing species to be rare. The use of a hierarchy of the three criteria, wherein provincial responsibility was assigned the most weight, resulted in the highest ranking for 13 species that exist only in Saskatchewan and no other Canadian province or territory. The list is a first step in identifying species deserving of conservation attention and/or further study, while the method itself was deemed to be highly relevant to conservation managers and decision makers due to its scale adaptability and fairly minimal resource requirements. 相似文献
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Effects of locally rare taxa on the precision and sensitivity of RIVPACS bioassessment of freshwaters 总被引:4,自引:0,他引:4
1. An overall aim in freshwater bioassessment is to use biological methods, metrics and forms of indices which are precise, in that they give repeatable results between replicate samples, but which are also sensitive to changes in environmental impacts and stresses. Here we studied the effects of excluding taxa with site‐specific River Invertebrate Prediction and Classification System (RIVPACS)‐type model expected probabilities less than (or equal to) a threshold Pt (0.0, 0.1, 0.2,…,0.9) on the value, precision and power to detect biological effects of environmental stress using the observed to expected ratios (O/E) of biotic indices used to assess the ecological status of U.K. river sites. 2. Amongst the 614 high quality GB RIVPACS reference sites, excluding taxa with low expected probabilities of occurrence gave less total variation (i.e. lower SD) in the estimates O/E for number of taxa (O/ETAXA) and the average score per taxon (O/EASPT). 3. A separate analysis of a replicated sampling study of sites from a wide range of physical types and qualities revealed that sampling variances in O/E for reference condition sites decreased as more locally rare taxa were excluded (but only up to Pt = 0.5 for O/EASPT). However, for moderately impacted and poor quality sites, estimates of both O/ETAXA and O/EASPT based on all (Pt = 0.0) or most taxa (i.e. Pt ≤ 0.3) had lower sampling variances and were more precise. 4. Within a very large independent set of test sites with a wide range of perceived levels of environmental stress, increasing the threshold Pt led to systematic compression of the realised O/E scale towards unity. Specifically, with increasing threshold, O/E values >1 are on average reduced, while O/E values <1 have a tendency to be higher and closer to unity (with the exception of O/EASPT for the most severely stressed sites). 5. Accuracy and statistical power to detect environmental stress (measured by the percentage of stressed sites with O/E below the lower 10‐percentile value for reference sites) was very similar using O/ETAXA for Pt up to 0.7. Using O/EASPT, power to detect overall general stress decreased slowly as Pt was increased; the rate of fall in power was slightly faster when restricted to sites subject to moderate or severe stress from organic inputs. 6. Taxa which are more sensitive to (organic) stresses [i.e. have high Biological Monitoring Working Party (BMWP) scores] tend to be naturally less widespread (i.e. amongst reference sites) and thus were found to have considerably lower average site‐specific expected probabilities; this may explain why the use of higher thresholds Pt can exclude more such sensitive taxa and lead to underestimation of the extent of impacts. 7. The standard U.K. RIVPACS sampling and sample processing procedures aim to identify all taxa within a sample. This may lead to a longer distribution tail of rarer (low probability) taxa than sampling methods based on a fixed count subsample and influence the practical effects of excluding rare taxa with low expected probabilities from bioassessments. 相似文献
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Effective conservation that preservesevolutionary entities and processes requiresconservation action that is targeted atappropriate taxonomic units. Molecularphylogenetics can contribute to the resolutionof taxonomic uncertainties by defining therelationships between populations and species,and allowing the recognition of taxonomicentities that reflect evolutionary history.Some uncertainty surrounds the status of taxain the Eucalyptus angustissima complex,which includes threatened taxa with restricteddistributions. The phylogenetic relationshipsbetween populations and taxa in the E.angustissima complex were investigated usingnuclear and chloroplast RFLP analysis.Phylogenetic relationships confirmed thegenetic differentiation of two taxa, identifiedspecies level divergence between two taxacurrently recognised at subspecies level, andestablished the identity of a previouslyundetermined population. Phylogeneticrelationships between the taxa were notcongruent with presumed relationships based onmorphological characters alone. 相似文献
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Katarina Andreasen 《Conservation Genetics》2005,6(3):399-412
Systematic research provides essential evidence for setting conservation priorities for rare and endangered taxa. Phylogenetic analyses can identify cryptic, genetically distinct lineages as well as actively interbreeding, and hence, non-distinctive lineages earlier perceived as separate taxa. A major aim of this study was to identify genetically distinct, rare lineages within two Malvaceae sister-genera, Sidalcea and Eremalche. The focus was two taxon-pairs each consisting of one rare and one more common taxon. The results demonstrate that even within two closely related genera, with a large number of rare taxa, molecular phylogenetic analyses can reveal contrasting degrees of evolutionary divergence and thus contrasting conservation implications for threatened taxa. Contrary to expectations, the substitution rate in the nuclear ribosomal transcribed spacers for annual Eremalche did not correspond to the faster evolutionary rate of annuals – compared to perennials – detected earlier within Sidalcea. Branch lengths in the (annual) Eremalche clade were shorter than those of annual members of Sidalcea. The phylogenetic analyses showed that the rare and endangered S. keckii and E. kernensis each are most closely related to a common species that has been regarded as insufficiently distinct to warrant separate taxonomic status. An additional aim of the study was to test the utility of the Phylogenetic Diversity (PD) measure to formalize the procedure of prioritizing conservation efforts. The measure demonstrated S. keckii (but not E. kernensis) to be genetically distinct from its closest relative and a good candidate for conservation. The PD measure was earlier used for assessing conservation priorities for areas, but proved useful to more objectively suggest conservation priorities among threatened taxa. Because this measure is calculated directly from the data, it retains more character information and gives a better representation of genetic diversity than other measures relying on tree topologies. 相似文献
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Field research on grassland fungi in Slovakia resulted in collection of several rare fungi, including also geoglossaceous
taxa, such as Microglossum viride (5 sites), Trichoglossum hirsutum (13 sites), Trichoglossum walteri (5 sites), Trichoglossum variabile (1 site), Microglossum olivaceum (2 sites), Thuemenidium atropurpureum (1 site). Last three species are new for Slovakia. 相似文献
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重庆市有 14种珍稀蝶类 ,主要分布在东北部、南部和东南部的 17个区 (市 )县 ,其中以江津、万盛、巫山、巫溪、城口、南川、彭水等 7个区 (市 )县最为重要。重庆市珍稀蝶类的保护对策是 ,加强法规制订和宣传 ,对濒危保护蝶类生物特性、生态学和行为学等方面进行专题研究 ,加强蝶类生栖地的保护和恢复 ,贯彻护·养·猎并举、以养蝶为主持续利用方针。 相似文献
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Anne-Marie Boulay Christian Bouchard Cecile Bulle Louise Deschênes Manuele Margni 《The International Journal of Life Cycle Assessment》2011,16(7):639-651
Purpose
As impact assessment methods for water use in LCA evolve, so must inventory methods. Water categories that consider water quality must be defined within life cycle inventory. The method presented here aims to establish water categories by source, quality parameter and user. 相似文献10.
The purpose of this study is to determine the conservation status of six vascular plant species with a restricted distribution or endemic to the mountainous areas in the province of Córdoba, central Argentina, by using the IUCN 1994 Red List Categories. The population number was estimated using a statistical method based on field data. The predicted decrease in the population number on a 10 yr projection was estimated taking into account the area to be used for future afforestation programs. To determine the area of occupancy and the extent of occurrence, an exhaustive bibliographical survey was carried out and herbarium specimens deposited in several institutions were revised. Aa achalensis, Adesmia cordobensis, Buddleja cordobensis, Croton argentinus and Oenothera cordobensis were considered as Vulnerable, whereas Solanum restrictum was assigned to the Endangered category. The categories assigned to Aa achalensis and Solanum restrictum are considered at the global level, whereas those assigned to Croton argentinus, Oenothera cordobensis, Adesmia cordobensis and Buddleja cordobensis should be considered at the local level. In all six cases the risk of extinction is high and suitable conservation strategies should be developed for each species. The most important threat factor is the planned afforestation in the area using exotic timber species; under these conditions the creation of a reserve in the studied area would be desirable in order to conserve five of the plants studied and, considering that 95% of its species are indigenous, the local flora as a whole. 相似文献
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Steffen Boch Daniel Prati Jörg Müller Stephanie Socher Henryk Baumbach François Buscot Sonja Gockel Andreas Hemp Dominik Hessenmöller Elisabeth K.V. Kalko K. Eduard Linsenmair Simone Pfeiffer Ulf Pommer Ingo Schöning Ernst-Detlef Schulze Claudia Seilwinder Wolfgang W. Weisser Konstans Wells Markus Fischer 《Basic and Applied Ecology》2013,14(6):496-505
There is a wealth of smaller-scale studies on the effects of forest management on plant diversity. However, studies comparing plant species diversity in forests with different management types and intensity, extending over different regions and forest stages, and including detailed information on site conditions are missing. We studied vascular plants on 1500 20 m × 20 m forest plots in three regions of Germany (Schwäbische Alb, Hainich-Dün, Schorfheide-Chorin). In all regions, our study plots comprised different management types (unmanaged, selection cutting, deciduous and coniferous age-class forests, which resulted from clear cutting or shelterwood logging), various stand ages, site conditions, and levels of management-related disturbances. We analyzed how overall richness and richness of different plant functional groups (trees, shrubs, herbs, herbaceous species typically growing in forests and herbaceous light-demanding species) responded to the different management types. On average, plant species richness was 13% higher in age-class than in unmanaged forests, and did not differ between deciduous age-class and selection forests. In age-class forests of the Schwäbische Alb and Hainich-Dün, coniferous stands had higher species richness than deciduous stands. Among age-class forests, older stands with large quantities of standing biomass were slightly poorer in shrub and light-demanding herb species than younger stands. Among deciduous forests, the richness of herbaceous forest species was generally lower in unmanaged than in managed forests, and it was even 20% lower in unmanaged than in selection forests in Hainich-Dün. Overall, these findings show that disturbances by management generally increase plant species richness. This suggests that total plant species richness is not suited as an indicator for the conservation status of forests, but rather indicates disturbances. 相似文献
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滇西北地区优先保护的植物群落类型 总被引:1,自引:0,他引:1
确定优先保护的地区和群落类型对生物多样性保护尤为重要.为评价滇西北地区优先保护的植物群落类型,针对植物群落在维持栖息地稳定及生物多样性保护方面的功能,依据科学性、层次性及可操作性等原则,构建了由3个层次6个指标构成的评价指标体系.6个与群落相关的指标分别是:物种多样性、珍稀濒危植物物种种数、保护植物级别、群落稀有性、特有植物物种种数和群落特有性.通过对滇西北地区现有资料的收集整理,共选出有样地数据的群落61个,归入13个植被亚型.根据数据的分布特征,利用等级赋值的方法制定了各个指标的评分标准.运用层次分析法与专家咨询法相结合确定权重,采用综合指数法对各群落及植被亚型进行评价,再进行重分类,划分出一级、二级、三级和一般保护类型.利用ArcGIS9.3软件制作不同保护级别的植被亚型的分布图,划分出优先保护的区域.综合评价划分出一级保护群落4类,二级31类,三级23类,一般3类;一级保护植被亚型1类,二级6类,三级6类.这些优先保护类型中,一级保护类型少量,分布在贡山县西南部和泸水县西南部的高黎贡山;二级保护类型较为集中地分布在研究区西北部高海拔地区各大山系及东南部高山地区;三级保护类型主要分布在研究区东南部海拔较低的区域以及独龙江、怒江、澜沧江和金沙江流域的河谷地段. 相似文献
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Julie Reveillaud Lo?s Maignien Murat A Eren Julie A Huber Amy Apprill Mitchell L Sogin Ann Vanreusel 《The ISME journal》2014,8(6):1198-1209
Microbial communities have a key role in the physiology of the sponge host, and it is therefore essential to understand the stability and specificity of sponge–symbiont associations. Host-specific bacterial associations spanning large geographic distance are widely acknowledged in sponges. However, the full spectrum of specificity remains unclear. In particular, it is not known whether closely related sponges host similar or very different microbiota over wide bathymetric and geographic gradients, and whether specific associations extend to the rare members of the sponge microbiome. Using the ultra-deep Illumina sequencing technology, we conducted a comparison of sponge bacterial communities in seven closely related Hexadella species with a well-resolved host phylogeny, as well as of a distantly related sponge Mycale. These samples spanned unprecedentedly large bathymetric (15–960 m) gradients and varying European locations. In addition, this study included a bacterial community analysis of the local background seawater for both Mycale and the widespread deep-sea taxa Hexadella cf. dedritifera. We observed a striking diversity of microbes associated with the sponges, spanning 47 bacterial phyla. The data did not reveal any Hexadella microbiota co-speciation pattern, but confirmed sponge-specific and species-specific host–bacteria associations, even within extremely low abundant taxa. Oligotyping analysis also revealed differential enrichment preferences of closely related Nitrospira members in closely related sponges species. Overall, these results demonstrate highly diverse, remarkably specific and stable sponge–bacteria associations that extend to members of the rare biosphere at a very fine phylogenetic scale, over significant geographic and bathymetric gradients. 相似文献
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S. Muller 《Biodiversity and Conservation》2002,11(7):1173-1184
The Lorraine region, in northeast France, harbours 77 protected plantspecies whose main localities are in grasslands. About 80% of them are very rareor rare (less than 15 localities) in that territory and are threatened by changes inagriculture. These species occur in a large range of grassland habitats,reflecting variability of climatic, hydrological and edaphic parameters, butalso of agricultural practices. A more precise analysis of managementrequirements was carried out for seven of these species, Euphorbiapalustris, Aster amellus, Pulsatillaalba, Carex hordeistichos, Thalictrumminus ssp. majus, Botrychiummatricariifolium and Ophioglossum vulgatum, whichwere represented on a triangle whose corners correspond to grazing, cutting andno or very low exploitation. It confirmed the large diversity of managementpractices required to ensure conservation of rare and threatened grassland plantspecies, even at a local level. These appropriate conservation measures havetherefore to be carried out or, at least, monitored by specialized natureconservation organizations. 相似文献
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Tracy D Ainsworth Lutz Krause Thomas Bridge Gergely Torda Jean-Baptise Raina Martha Zakrzewski Ruth D Gates Jacqueline L Padilla-Gami?o Heather L Spalding Celia Smith Erika S Woolsey David G Bourne Pim Bongaerts Ove Hoegh-Guldberg William Leggat 《The ISME journal》2015,9(10):2261-2274
Despite being one of the simplest metazoans, corals harbor some of the most highly diverse and abundant microbial communities. Differentiating core, symbiotic bacteria from this diverse host-associated consortium is essential for characterizing the functional contributions of bacteria but has not been possible yet. Here we characterize the coral core microbiome and demonstrate clear phylogenetic and functional divisions between the micro-scale, niche habitats within the coral host. In doing so, we discover seven distinct bacterial phylotypes that are universal to the core microbiome of coral species, separated by thousands of kilometres of oceans. The two most abundant phylotypes are co-localized specifically with the corals'' endosymbiotic algae and symbiont-containing host cells. These bacterial symbioses likely facilitate the success of the dinoflagellate endosymbiosis with corals in diverse environmental regimes. 相似文献
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Fire is a key natural and anthropogenic disturbance factor across many ecosystems, and also an important conservation management
tool. However, little is known about arthropod responses to fire, particularly in Mediterranean-type ecosystems, including
the biodiverse Cape Floristic Region (CFR). We investigate here the relative variety of responses by different arthropod taxa
to fire, and ask whether single-taxon or multi-taxa approaches better suit post-fire biomonitoring for conservation management.
Sampling involved multiple techniques and was conducted before fire, 1 year after fire, and 3 years after fire, with unburned
areas as controls. Before-and-after statistics were used to identify changes in arthropod populations and assemblages as a
result of fire, and between treatment and control sites. However, this was against a background of the annual effects having
a major influence on the arthropods, irrespective of fire. Abundance was so variable, even in control plots, that we found
it an unreliable indicator of the impact of fire. Overall, arthropods were remarkably resilient to fire, with most taxa recovering
in species richness and assemblage composition within 3 years of the fire. Although all taxa showed resilience to fire, there
was nevertheless little congruence in temporal recovery of the various taxa. Our results highlight the shortcomings of monitoring
fire impacts using only a single-taxon without prior testing for complementarity or sensitivity to fire, while emphasizing
the importance of sampling a wide range of taxa to represent overall responses of compositional biodiversity. From this, we
recommend, at least for the CFR, that a cross-section of taxa, such as butterflies, ants, and scarab beetles, be used for
monitoring arthropods in recovery/fire management conservation programmes. We also recommend that such monitoring be considered
against the background of large annual variation seen in unburned areas. 相似文献
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In vitro techniques are very useful for conserving plant biodiversity, including (a) genetic resources of recalcitrant seed and vegetatively
propagated species, (b) rare and endangered plant species and (c) biotechnology products such as elite genotypes and genetically
engineered material. Explants from recalcitrant seed and vegetatively propagated species can be efficiently collected under
field conditions using in vitro techniques. In vitro culture techniques ensure the production and rapid multiplication of disease-free material. Medium-term conservation is achieved
by reducing growth of plant material, thus increasing intervals between subcultures. For long-term conservation, cryopreservation
(liquid nitrogen, −196°C) allows storing plant material without modification or alteration for extended periods, protected
from contaminations and with limited maintenance. Slow growth storage protocols are routinely employed for a large number
of species, including numerous endangered plants, from temperate and tropical origin. Cryopreservation is well advanced for
vegetatively propagated species, and techniques are ready for large-scale experimentation in an increasing number of cases.
Research is much less advanced for recalcitrant species due to their seed characteristics, viz., very high sensitivity to
desiccation, structural complexity and heterogeneity in terms of developmental stage and water content at maturity. However,
various technical approaches should be explored to develop cryopreservation techniques for a larger number of recalcitrant
seed species. A range of analytical techniques are available, which allow understanding physical and biological processes
taking place in explants during cryopreservation. These techniques are extremely useful to assist in the development of cryopreservation
protocols. In comparison with crop species, only limited research has been performed on cryopreservation of rare and endangered
species. Even though routine use of cryopreservation is still limited, an increasing number of examples where cryopreservation
is used on a large scale can be found both in genebanks for crops and in botanical gardens for endangered species. 相似文献
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