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.
Capsule Skylarks breeding in Ireland prefer extensive grassland habitats and almost completely avoid tillage habitats.

Aims To describe the distribution and habitat use of breeding Skylarks in Ireland, particularly in lowland agricultural habitats, and to use this information to inform conservation measures for this species.

Methods Countryside Bird Survey (CBS) and Farmland Bird Project (FBP) data were examined to determine large-scale (national) distribution and habitat selection, in addition to smaller-scale (farm- and field-level) habitat use. The CBS is a national breeding bird monitoring scheme involving 397 1-km squares. The FBP collected detailed bird and habitat data from 122 farms.

Results CBS and FBP data both showed significant regional differences in breeding Skylark densities, with the highest relative abundances in the northwest and west. Dry grassland/grass moor habitats supported the highest densities of breeding Skylarks in the CBS, which were significantly higher than in improved grassland or tillage. At the farm-level, Skylark numbers were positively related to wetland habitats but negatively associated with trees in field boundaries, dense ground vegetation and overall density of farm boundaries. At the field-scale, larger fields and unimproved grasslands were preferred.

Conclusion Agri-environment measures tailored to region-specific requirements and to the relatively local habitat preferences of target species are required if population declines of species of conservation concern, including Skylarks, are to be reversed.  相似文献   

2.
Summary

In recent years, fungal conservation in Scotland has made substantial progress, particularly as a result of field surveys undertaken in support of the Biodiversity Action Plans developed for selected species. Results are presented from four recent surveys: (i) fungal diversity in conifer plantations, (ii) hydnoid (‘tooth’) fungi in coniferous forests, (iii) grassland fungi, (iv) fungal survey of the Mar Lodge Estate. These surveys have substantially improved knowledge of the conservation status of a number of threatened taxa, and have also provided insights into patterns of fungal diversity at a range of scales. The results indicate that some of the fungal communities of Scotland, such as those associated with unimproved grasslands, are of international conservation importance. The implications of the survey results for conservation management are discussed, and suggestions are made regarding priorities for future work. In particular, there is a need to provide conservation managers with guidance on how fungal conservation can be achieved in practice.  相似文献   

3.
Grassland is a land cover in the area of conflict between agriculture and conservation, where intensification of land use is a major threat to grassland biodiversity. Grassland use intensity is a key factor for the conservation value of grassland, and detailed spatial data on grassland use intensity is needed to improve strategies for biodiversity conservation. A new remote sensing-based approach using multi-temporal high resolution RapidEye satellite data was developed in the present study that makes a large-scale assessment of grassland use intensity possible. RapidEye is a constellation of five satellites with 6.5 m spatial resolution, which allows frequent and timely image acquisition targeted at specific growing seasons. Semi-natural grassland, extensively used grassland, intensively used grassland and tilled grassland could be reliably differentiated at the management plot level in a study area in southern Germany. Various combinations of images from different observation dates have been tested as classification input and their overall classification accuracies were validated by field data. Best results were achieved using a combination of five multi-temporal scenes with an overall accuracy of 85.7%. A three-scene combination resulted in an overall accuracy of 82.2%. The analysis showed that seasonal aspects are very important when selecting adequate observation dates. Grassland use intensity was also assessed on peatlands using a peat soil map, since land use intensity significantly affects greenhouse gas emissions from peatlands. The results demonstrate the potential of targeted multi-spectral, high spatial resolution remote sensing for the large-scale monitoring of dynamic habitats, which is of vital importance to support various environmental conservation schemes through improved monitoring and reporting capabilities.  相似文献   

4.
Summary

National Vegetation Classification (NVC) data from surveys of Scottish unimproved lowland grasslands were reviewed. The surveys dated from 1980 to 2000. The mapped area of each lowland grassland NVC type was measured or, where vegetation maps were not of sufficient quality, estimated. These measurements and estimates were summed to give the total recorded area of each lowland grassland NVC type. An estimate of the total area likely to occur throughout Scotland was made for the more thoroughly recorded lowland grassland NVC types.

The data from this review has been used to create Scottish Natural Heritage's Lowland Grassland Database, containing details of all lowland grassland sites recorded by the grassland surveys, their grid reference, conservation status, site area, surveyor, date of survey, NVC lowland grassland types present and their areas. Council Area, old local authority District and SNH Area are also included.

A total of 8700 ha of unimproved lowland grassland NVC types (excluding coastal grasslands) has been recorded in Scotland. This habitat is semi-natural and of high conservation value.

The total area of unimproved lowland grassland in Scotland is estimated to be in the order of 30,000 ha.  相似文献   

5.
6.
【目的】环境真菌是导致博物馆藏品微生物病害的主要原因之一。博物馆库房环境中由于藏品材质、来源和保存环境的差异,其环境真菌具有较高的多样性;在博物馆空调系统的影响下,藏品库房之间还存在真菌扩散的现象。研究不同材质藏品库房空气中真菌组成差异及其种类随季节变化情况,是开展博物馆环境微生物风险预警和防范的基础。【方法】选择某博物馆的铁器库房和丝织品库房,在一年时间内采用撞击法每两个月采样一次,通过ITS rDNA序列对真菌的种类和组成进行分析。【结果】通过扩增子测序,共获得5门20纲184科的真菌信息,其中超过半数存在显著的季节波动。研究结果显示,一方面,铁器库房与丝织品库房存在特异性的、较为稳定的基础真菌菌群,这些真菌受季节波动的影响较小;另一方面,在相对湿度较高的夏季,多种具有蛋白类、纤维素类基质藏品损伤能力的真菌在两类库房出现了显著的富集,对藏品具有潜在威胁。此外,部分真菌在生长过程中会分泌酸类物质,不利于藏品保护。【结论】本研究为博物馆环境有害真菌的防治工作提供了一定科学依据,对博物馆藏品的预防性保护具有重要意义。  相似文献   

7.
Making up for air pollution related mortality and accounting for the number of deaths has become an important environmental indicator in its own right, but differences across the Atlantic over how to account for these are making it difficult to find common ground in climate policy appraisals, where co-benefits from reducing air pollution of fossil fuels is to be factored in. This article revisits established quantification methodologies for air pollution related mortality applied by government agencies in USA and EU. Demographic lifetables are applied to explore uncertainties over latency periods and the number of affected victims. These lifetable simulations are based on WHO consensus estimates for the mortality risk ratio related to long-term exposures and suggest an average loss of life expectancy of 9–11 years for an annual air pollution exposure increase of 10 ugPM2.5/m3. With a common OECD base value approach the air pollution costs related to fossil fuels are found to be about 3 times lower with EU versus US methodology.  相似文献   

8.
《Journal of bryology》2013,35(4):255-265
Abstract

The military training area on Salisbury Plain contains the largest area of chalk grassland in western Europe. The grassland swards, though relatively tall, are often rich in flowering plant species. The bryophyte flora of areas disturbed in five different ways (prehistoric earthworks, twentieth century rifle ranges, ant-hills, vehicle tracks and shell-holes) was compared to that of adjacent, relatively undisturbed grassland. There was no significant difference in bryophyte cover between quadrats on disturbed ground and the controls, but the disturbed sites supported more bryophyte species per quadrat. Of the 55 taxa recorded, 38 species were at least three times more frequent in the disturbed than the undisturbed sites, compared to four which were at least three times more frequent in the control sites. The species favouring disturbed conditions included several bryophytes characteristically associated with chalk soils in southern England, including some that fruit freely (e.g. Microbryum curvicollum, Tortula lanceola) and others that fruit very rarely (e.g. Abietinella abietina, Entodon concinnus). These results are discussed in relation to the conservation of bryophytes and other disturbance-tolerant and disturbance-dependent species on Salisbury Plain and in the wider context of the protection of the bryophytes of chalkland habitats.  相似文献   

9.
Capsule Regrowth rate of tail feathers is more strongly affected compared to feather length and symmetry.

Aims To assess the value of avian feathers as bioindicators.

Methods The origin and persistence of fluctuating asymmetry (FA) in homologous pairs of regrowing feathers was studied in captive birds under different levels of environmental stress, respresented by exposure to lead (Pb). Homologous feathers of individually housed birds were plucked synchronously or with a delay of seven days. We measured growth rate, regeneration time, final size and FA of regrown feathers and related them to Pb stress.

Results Asymmetry decreased as feathers reached their final length. This was not due to compensatory growth but rather a consequence of the programmed growth trajectory of single feathers. Tail feathers grown under higher Pb pollution showed increased regeneration times, decreased growth rates and shorter lengths, but no changes in development times nor in FA. For differences between both (i) original and induced feathers and (ii) control and Pb treatment, effect sizes of parameters related to feather development (growth bar width, growth rate, regeneration and development time) were consistently larger than those related to the resulting phenotype (feather length and FA).

Conclusions Growth bar widths in particular provide an applicable, sensitive and reliable indicator of adverse conditions such as Pb pollution and experimental conditions. In general, phenotypic characteristics that retrospectively allow estimation of growth rates may be more suitable for monitoring environmental stress than sizes or asymmetries of full-grown traits.  相似文献   

10.
Summary

Members of the genus Hygrocybe are ubiquitous and colourful components of many undisturbed and nutrient-poor grasslands in the UK. Through a number of detailed surveys of the distribution of Hygrocybe spp. and of genera showing similar patterns of occurrence (e.g. Clavaria spp., Entoloma spp., Geoglossum spp.) a picture is gradually emerging of the more important ‘waxcap grassland’ sites, and of those species in greatest need of protection. Waxcap fungi are far from ideal experimental organisms which explains why so little has been published about their biology and ecology. They cannot be cultured on laboratory media and the correct conditions for inducing spores of most species to germinate have yet to be established. Nevertheless approaches such as isotope ratio mass spectrometry and the use of molecular biology techniques are beginning to provide an insight into the role played by these organisms in grassland ecosystems, and why they are so adversely affected by many agricultural practices. Current field experiments at various sites including Sourhope near Kelso will also permit investigations into waxcap ecology to be correlated with parallel studies of other members of the soil biota.  相似文献   

11.
This investigation determined the response of soil microbial communities to enhanced UV‐B radiation and disturbance in upland grassland. A factorial field experiment encompassing two levels of UV‐B supplementation (simulating ambient and a 30% increase in stratospheric ozone) and two levels of disturbance (disturbed and undisturbed) was established at Buxton Climate Change Impacts Laboratory, Derbyshire, UK, and maintained for 7 years prior to sampling. Enhanced UV‐B increased microbial utilization of carbohydrates, carboxylic acids, polymers and aromatic compounds present in Biolog® GN plates when inoculated with soils taken from disturbed plots, but did not affect carbon utilization of soil microbial communities associated with undisturbed plots (UV‐B×Disturbance interaction, P<0.05 for each substrate type). UV‐B treatment did not affect numbers of bacteria or fungi. Direct microscopic counts showed fewer bacteria in soil originating from disturbed plots than from undisturbed plots (Disturbance, P<0.001), although a greater number of culturable bacteria and fungi were isolated from disturbed than from undisturbed soils (Disturbance, P<0.001). No UV‐B‐ or disturbance‐related differences in protein, starch or urea hydrolysis were exhibited by bacterial isolates. UV‐B treatment did not affect total plant biomass within undisturbed plots or the biomass of individual groupings of grasses, forbs and mosses. Per cent root length colonized by arbuscular mycorrhizal fungi (AMF) was not affected by enhanced UV‐B radiation in the undisturbed plots. Neither AMF nor plant biomass was measured in disturbed plots. The key findings of this study show that UV‐B‐mediated alterations in carbon utilization occurred in soil microbial communities subjected to disturbance, but such changes were not observed in communities sampled from undisturbed grassland. Differences in the catabolic potential of microbial communities from disturbed grassland subjected to enhanced UV‐B are probably related to plant‐mediated changes in resource availability or quality.  相似文献   

12.
Abstract

Plants can be used naturally to mitigate environmental pollution, such as air pollution; however, it is important to evaluate plant susceptibility to air pollution when considering green space creation in urban areas. In this study, we investigated the biochemical and physiological parameters, including pH, and ascorbic acid, relative water, total chlorophyl, proline, soluble sugar, protein, and free amino acid contents of two gymnosperm tree species, Cupressus arizonica Greene and Juniperus excelsa Bieb. Using these data, we computed the Air Pollution Tolerance Index (APTI) and Anticipated Performance Index (API) of the trees at five sites in Isfahan, Iran, to determine their applicability for greenbelt establishment. Our results indicated that these evergreen species are good indicators of air pollution and can be used as an early warning tool for air pollution level that is harmful to human health.  相似文献   

13.
According to the Convention on Biological Diversity (CBD) the development of bioindicators is extremely necessary to achieve the conservation targets by 2010, and insects are considered an effective group for this goal. Drosophilids are regarded as potential indicators, although this idea remains untested. Therefore, we followed up a protocol to test the drosophilid potential indicator for human disturbance in the Brazilian Savanna, one of the richest and most threatened tropical biomes in the world. Sampling was undertaken in one urban environment and two biological reserves, representing four habitat types (undisturbed gallery forest, disturbed gallery forest, undisturbed savanna, and urban environment). We examined differences in the drosophilid assemblages among habitat types and used the Indicator Value (IndVal) method to point out the indicator species. We also tested the two-stage indicator validation, a protocol recently proposed in the literature, to validate the indicator species for undisturbed gallery forest and savannas, in independent samples. The assemblage variables varied mainly in undisturbed gallery forests, and reflected changes from an undisturbed to a disturbed stage. The IndVal associated with the two-stage protocol showed reliable characteristic species, which are very helpful for diagnostic surveys. Likewise, species that can detect changes in the habitats were also found. We found a set of indicators, which together may be very efficient for both assessing and reflecting a variety of conditions, improving the confidence of the bioindication system, expanding the taxonomic options for bioindicators, and therefore, contributing to the conservation of this region.  相似文献   

14.
环境胁迫与生物防御反应   总被引:2,自引:0,他引:2  
吴亚  金翠霞 《生态学杂志》1990,9(5):46-49,55
生物的生存总是逃避不了周围各种环境胁迫因素的影响。非生物因素如温度、水分、湿度、光照、营养、环境污染、物理干扰和土壤坚实度等;生物因素如有害生物的袭击等。兴衰存亡的关键,除了取决于胁迫的种类、强度  相似文献   

15.
Documented Utility and Biocultural Value of Aloe L. (Asphodelaceae): A Review. The genus Aloe L. (Asphodelaceae) comprises 548 accepted species, of which at least one-third are documented as having some utilitarian value. The group is of conservation concern due to habitat loss and being extensively collected from the wild for horticulture and natural products. Cultural value is increasingly important in the effective conservation of biodiversity. The present study evaluated the biocultural value of the known uses of Aloe, excluding the domesticated and commercially cultivated A. vera. Over 1,400 use records representing 173 species were collated from the literature and through personal observation; this paper presents a synopsis of uses in each of 11 use categories. Medicinal uses of Aloe were described by 74% of the use records, followed by social and environmental uses (both 5%). Species yielding natural products, notably A. ferox and A. perryi, were most frequently cited in the literature. Consensus ratios indicate that the most valued uses of Aloe are in medicine and pest control against arthropods and other invertebrates.  相似文献   

16.
Aim We assess changes in plant species richness and changes in species dissimilarity at local scale in Swiss grassland between the time periods 2001–2004 and 2006–2009. Further, we provide an ecological interpretation of the observed taxonomic homogenization of vascular plants. Location Switzerland. Methods Changes in species richness and changes in Simpson dissimilarity index of vascular plants in grassland (meadows and pastures) were examined. The analyses were based on species lists recorded on 339 10‐m2 sample plots from a systematic sample covering the entire Switzerland. Each sample plot had been surveyed once in 2001–2004 and once in 2006–2009 with 5 years between the first and the second survey. Changes in species dissimilarity were interpreted by comparing the relative contribution of several indicator species groups. Results Mean species richness of vascular plants in grassland increased during the study period. In contrast, species dissimilarity of plants decreased, suggesting local‐scale floristic homogenization of grassland in Switzerland. It was mostly because of the spread of common species, namely the species that are tolerant to high nutrient levels, the species of low conservation value and the species adapted to moderate temperature levels that led to taxonomic homogenization. Target species for conservation did only marginally affect taxonomic homogenization. In contrast to the predictions from studies of taxonomic homogenization on larger scales, the taxonomic homogenization of grassland at local scale was not explained by the spread of neophytic species. Main conclusions The biotic diversity of grassland in Switzerland changed considerably between 2001–2004 and 2006–2009. The observed taxonomic homogenization was merely because of the spread of common species. Local‐scale changes in land use regimes implemented by agri‐environmental schemes and other conservation efforts on parts of the entire grassland area were, apparently, not enough to prevent the total grassland from recent taxonomic homogenization.  相似文献   

17.
青藏高原草地存在价值研究——以玛曲为例   总被引:2,自引:0,他引:2  
草地存在价值研究是强化人们环境保护意识的有力工具,也是制定资源利用战略的决策依据。运用条件价值评估方法中(Contingent Valuation Method,CVM)的最大意愿支付(Willingness to Pay,WTP)技术,对青藏高原东缘玛曲草地的存在价值进行了系统研究,结果显示:2005年,牧户的平均WTP为339元/a,总存在价值为0.03×10~8元/a;收入与WTP呈显著正相关关系。据此推断,2016年牧户的平均WTP为407元/a,总存在价值为0.033×10~8元/a。存在价值小,主要是因为当地人口基数小。如果考虑玛曲草地对全球生物多样性保育的贡献,以及对黄河水源所具有的涵养功能,则其总存在价值将倍增,其中2005年为636×10~8元/a,2016年为763×10~8元/a,增幅约为20%,与当地居民的收入增长相当。这一结果表明,与玛曲草地的保护成本相比,其存在价值极其显著,应纳入成本-效益分析之中;存在价值具有动态性,应根据收入变化状况进行连续评估,以反映其真实价值,从而确保政策制定者做出正确决策。  相似文献   

18.
The diversity of fungi in semi-natural grasslands is poorly known, partly due to difficulties in species identification in the field but also because there are few specialists available. Diversity assessments of grassland fungi would be facilitated if a potential surrogate group for fungal diversity could be identified. The aim of this study was to assess whether plant diversity patterns in semi-natural grasslands are congruent with diversity patterns of Waxcap (Hygrocybe spp.) fungi. Waxcaps, together with several other groups of fungi (e.g. the genera Entoloma, Dermoloma, Camarophyllopsis, and the families Clavariaceae and Geoglossaceae) have habitat requirements similar to many plants typical for semi-natural grasslands and they are all threatened by ceased management and nutrient enrichment. Diversity data from 31 semi-natural grasslands in southern Sweden were used to examine if there is congruence in species richness, nestedness, β-diversity and species composition between plants and Hygrocybe fungi. Species richness of Hygrocybe was significantly positively correlated with plant richness, although the relationship was not strong (r2=0.14). Both plant and Hygrocybe species composition was significantly nested, i.e. species-poor sites contain a subset of species from species-rich sites, which suggests that rare species mostly occur in the species-rich sites. A species similarity analysis between the grassland sites showed that there is low overlap between species composition of plants and Hygrocybe, indicating that conservation decisions based solely on plants may not fulfil the requirements of the Hygrocybe species. The conclusion is that there is low congruence between plant and Hygrocybe species diversity, making plants a poor surrogate group for Hygrocybe fungi, and probably also for other grassland fungi.  相似文献   

19.
Air pollution is the single largest environmental risk today and is increasing in developing countries. In addition, exposure to air pollution is correlated to poor socioeconomic conditions owing to political processes and cultural and historic occupation of land. Ports have several structures that are potential emitters of pollutants such as large ship engines, diesel trucks, and trains. Owing to the considerable costs of implementing direct monitoring networks, alternatives like biomonitoring are an interesting approach to evaluate the environmental status of a particular area using living organisms or their parts such as bark, even though the use of bark as a biomonitor has several problems such as difficulties in determining the exposure period and its correlation with human exposure. Therefore, the use of a complementary mathematical logic is necessary. This study describes a methodological approach to evaluate the environmental risk from air pollution integrating data on environmental pollutants from tree bark using Fuzzy logic, based in the port city of Paranaguá in the state of Paraná in Brazil, and validated using income indicators. The results indicate that the risk distribution patterns have an inverse relationship with the income indicator, i.e., higher risk levels indicate lower income levels and vice versa. It was concluded that the system was able to identify the distribution of risk and that there is a context of environmental injustice in the region, where the environmental risk related to air pollution is inversely proportional to income levels. This type of information provides a decision making tool for environmental risk analysis from air pollution and can be used in the definition of public policies.  相似文献   

20.
北方草地是我国天然草地主体部分,其生态功能对提升生态系统稳定性、保障国家生态安全具有重要的作用。在北方草地生态功能分区基础上,开展2011-2015年不同功能区内防风固沙、土壤保持、水源涵养等生态功能评估,探明其现状和空间格局,为北方草地生态功能分区研究提供评估数据,也为推进草地生态系统保护与修复工作提供科技支撑。结果表明:(1)北方草地防风固沙能力为32.44 t hm-2 a-1,防风固沙量为89.22亿t/a。半干旱草原区防风固沙能力和固沙量最大,分别为68.76 t hm-2 a-1和29.16亿t/a,其固沙量占北方草地固沙总量的32.68%。(2)北方草地土壤保持能力为124.5 t hm-2 a-1,土壤保持量为243.59亿t/a。土壤保持功能的空间异质性较大,暖性灌草丛区土壤保持能力最大,为431.52 t hm-2 a-1;高寒草甸区土壤保持量最多,为105.36亿t/a,占北方草地土壤保持总量的43.19%。(3)北方草地水源涵养能力为93.03 m3 hm-2 a-1,水源涵养量为288.98亿m3/a。高寒草甸区和高寒草原区水源涵养能力较大,分别为211.09 m3 hm-2 a-1和118.04 m3 hm-2 a-1。两个区域的水源涵养量也较多,分别为125.36亿m3/a和72.13亿m3/a,合占北方草地水源涵养总量的68.34%。整体上,北方半干旱草原区、暖性灌草丛区、高寒草甸区和高寒草原区对发挥我国草地防风固沙、土壤保持、水源涵养等生态多功能效益、提升生态系统服务和稳定性具有极其重要的作用。  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