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1.
《Ecological Indicators》2008,8(5):466-475
Measures used to describe the floristic structure of a habitat can vary in their ability to express trends in plant composition along anthropogenic disturbance gradients. This study was based on a survey of vascular plant biodiversity performed along stream bank habitats within an agricultural landscape in southeastern Ontario, Canada. The accuracy of several measures of plant biodiversity – including those related to a regional floristic quality assessment system – was examined to compare their ability to recognize a gradient of anthropogenic disturbance and associated floristic quality along the stream bank habitats. The floristic quality assessment system is a scheme in which all vascular plants of a region have been assigned a score corresponding to a qualitative conservation value based on habitat fidelity and tolerance of disturbance (native species), and on invasiveness (non-native species). Data were collected from a priori designated disturbed, moderate, and pristine zones along 27 stream sections exhibiting a length-wise disturbance gradient. A detrended correspondence analysis (DCA) was used to isolate the plant compositional gradient present along the stream sections. The measures of plant biodiversity recorded in the different study sites were then ranked by the degree to which they were linearly correlated with the identified compositional gradient of the DCA. The “% non-native plant species” measure was most effective at expressing the gradient, though it incorporated nothing about the fidelity and sensitivity of native plant species present in individual zones. Several measures associated with the floristic quality assessment system – including the mean coefficient of “conservatism” (mCC) – were also effective in identifying the gradient, and had the additional benefit of considering the contribution of each native species in a plot. The simple measure of “total plant species richness” proved to be a poor linear indicator due to a quadratic trend across the whole of the compositional gradient. The floristic quality assessment system proved to be a valuable tool for assessing conservation values of the selected sites. It should be extended to include further regions in Canada and North America in general. Our results further suggest that stream banks associated with open non-crop agricultural property are highly susceptible to colonization by non-native upland plants and species of low conservation interest, and that the presence of wooded areas surrounding these same streams is associated with higher numbers of native and disturbance sensitive plant species present in the bank habitats. 相似文献
2.
The Guadiana River basin’s freshwater fish species richness, endemicity and threatened status (92% of native species are threatened)
highlight the need for a large-scale study to identify priority areas for their conservation. One of the most common problems
in conservation planning is the assessment of a site’s relative value for the conservation of regional biodiversity. Here
we used a two-tiered approach, which integrates an assessment of biodiversity loss and the evaluation of conservation value
through site-specific measures. These measures based on the reference condition approach introduce the ability to make objective
comparisons throughout the Guadiana River basin, thus avoiding a priori target areas. We identified a set of biodiversity
priority areas of special conservation significance—which contain rare taxa as well as intact fish communities—because of
their outstanding contribution to the basin’s biodiversity. The inclusion of complete sub-basins in these priority areas might
guarantee an optimal solution in terms of spatial aggregation and connectivity. However, the high spatial fragmentation to
which the Guadiana River basin is submitted due to river regulation highlights the necessity of a systematic approach to evaluate
the capability of the identified priority areas to maintain the Guadiana’s freshwater fish biodiversity.
Handling editor: R. H. Norris 相似文献
3.
可持续经营框架下阔叶红松林区生物多样性间接评价体系的研究 总被引:12,自引:0,他引:12
森林生物多样性的保护和持续利用是森林可持续经营的重要内容,如何快速有效地评价生物多样性是当前森林经营实践中面临的重要问题。本文以可持续发展为指导思想,针对阔叶红松林区森林可持续经营中的生物多样性保护问题,提出了一套生物多样性间接评价的体系和评价方法。生物多样性间接评价的基本原理是以物种与生境的关系、森林自然干扰状况、物种间的相互关系和对特殊生境及敏感物种的考虑等为基础的。依据阔叶红松林区的干扰状况、林分一般状况、立木层、灌木层、草本层、附生植物和藤本植物等的特点,采用重复累加的方法,制定了阔叶红松林区林分生物多样性间接评价的打分表。在一个森林经营单位(林业局或林场)进行生物多样性的保护时,首先应根据不同森林类型对干扰的适应和抵抗力大小确定对各类森林优先保护的次序,然后再在各类森林的不同小班中进行生物多样性间接评价打分表的填写,最后根据不同小班生物多样性得分的多少确定其保护的等级或先后次序。生物多样性间接评价调查可以结合森林经理调查来进行。 相似文献
4.
Freshwater ecosystems support biological communities with high species richness and conservation interest. However, these ecosystems are highly altered by human intervention and threatened worldwide, making them a priority in conservation planning and biodiversity monitoring. Bryophytes, including several conservation-interest taxa, are recognized indicators of ecological status in freshwaters. We aimed to develop a framework for designing monitoring networks to detect trends in aquatic and semi-aquatic bryophyte communities, prioritizing high-conservation interest communities in different contexts of human pressure (specifically, resulting from the intersection of two criteria: (i) protection status and (ii) presence of a potential impact area).The framework consists of three steps: (1) Spatial modelling of biodiversity; (2) Spatial conservation prioritization; and (3) Model-assisted monitoring network design. Community-level modelling was used to model the distribution of the main bryophyte assemblages in the study area. A conservation prioritization software was utilized to identify areas with high conservation value. The monitoring network was designed using stratified random sampling and unequal-probability sampling techniques to target high conservation value sites distributed across different contexts of human pressure.We have identified four distinct community types, each characterized both by a small group of common and dominant species, and by small group of rarer, conservation-interest species. This typification of four species assemblages occurring in the study area, also highlighted those with potentially higher conservation-interest. The most valuable areas for the conservation of aquatic and semi-aquatic bryophyte communities coincide with specific environmental zones: mountainous areas in Lusitania, large watercourses in the Mediterranean North and some locations in the Mediterranean Mountains. Finally, we obtained a potential monitoring network consisting of 64 monitoring points, unequally distributed across different contexts of human pressure, privileging locations with higher conservation value.The framework presented here illustrates the potential of combining biodiversity modelling, spatial conservation prioritization and monitoring design in the development of monitoring networks. Namely, this framework allowed us to counter data deficiencies, to identify high priority areas to monitor and to design a monitoring network considering different scenarios of human pressure at a regional scale.This framework can also be valuable for conservation efforts as an approach to monitoring conservation-interest biodiversity features in anthropogenically modified riverscapes, which present different degrees of human pressure and the cumulative effects of these different impact elements. Moreover, this approach allows for the comprehensive monitoring of biodiversity values important for management at the national and regional levels. In addition, this framework is one of the first efforts in the development of monitoring networks that target aquatic and semi-aquatic bryophyte communities, a long-neglected plant group of high ecological and conservation importance in freshwater ecosystems. 相似文献
5.
生物多样性保护优先区是我国为加强生物多样性保护和监管划定的重要区域,目前部分优先区已陆续开展生物本底资料的调查评估工作,但受限于经费、时间等条件,对区内所有县域或网格全覆盖式科考,既不现实也无必要,因而区域尺度的抽样设计是一个亟需解决的关键问题。以武陵山生物多样性保护优先区为例,结合层次聚类和系统抽样方法,同时考虑历史调查资料的系统完整程度和空间保护属性,提出了一个科学可行的抽样方案。首先将研究区域内的所有县域聚为5类,每类挑选出2个重点县域,共获得6个历史上进行过系统科学考察的县域和4个本底资料相对缺乏的县域,进而挑选出76个重点调查网格(10 km×10 km),其中生物多样性富集网格36个,保护区外的人类干扰网格40个,抽样比例为11.09%,每个网格平均调查经费为2.52万元。该抽样策略区分了调查层次并突出重点区域,使调查和评估更有针对性,进一步完善了保护优先区基础调查系统,也强化了项目管理能力,对其他保护优先区项目开展具有一定参考价值。 相似文献
6.
Pablo A. Imbach Bruno Locatelli Luis G. Molina Philippe Ciais Paul W. Leadley 《Ecology and evolution》2013,3(9):2917-2932
Climate change is a threat to biodiversity, and adaptation measures should be considered in biodiversity conservation planning. Protected areas (PA) are expected to be impacted by climate change and improving their connectivity with biological corridors (BC) has been proposed as a potential adaptation measure, although assessing its effectiveness remains a challenge. In Mesoamerica, efforts to preserve the biodiversity have led to the creation of a regional network of PA and, more recently, BC. This study evaluates the role of BC for facilitating plant dispersal between PA under climate change in Mesoamerica. A spatially explicit dynamic model (cellular automaton) was developed to simulate species dispersal under different climate and conservation policy scenarios. Plant functional types (PFT) were defined based on a range of dispersal rates and vegetation types to represent the diversity of species in the region. The impacts of climate change on PA and the role of BC for dispersal were assessed spatially. Results show that most impacted PA are those with low altitudinal range in hot, dry, or high latitude areas. PA with low altitudinal range in high cool areas benefit the most from corridors. The most important corridors cover larger areas and have high altitude gradients. Only the fastest PFT can keep up with the expected change in climate and benefit from corridors for dispersal. We conclude that the spatial assessment of the vulnerability of PA and the role of corridors in facilitating dispersal can help conservation planning under a changing climate. 相似文献
7.
Abstract Old-growth forests in south eastern Australia are important for biodiversity conservation, recreation, carbon storage, social values and, to a declining extent, for timber production. Developing a comprehensive definition of old-growth forest that can apply across all Australian vegetation types has been challenging. Old growth can be viewed from ecological and social perspectives. For policy and management purposes old growth has been defined as a growth stage in forest development, incorporating ecological maturity and lack of evidence of past disturbance. Classification and assessment of old growth has largely been restricted to those areas covered by regional forest agreements (RFAs) between different states and the Federal Government. Old growth can be impacted by wildfire, timber harvesting, insect pests, diseases and other disturbances. Climate change will also present challenges for the future management of old-growth forests. There is increasing scientific understanding of the relationships between species, forest growth stage and old-growth forest attributes. To meet biodiversity conservation objectives, the management focus is shifting from assessing and protecting old-growth forests, to providing for forests across the landscape with old-growth attributes. This approach may be at odds with other conceptions of old growth based on notions of undisturbed systems free of human influence. 相似文献
8.
Mountain biodiversity conservation and management: a paradigm shift in policies and practices in the Hindu Kush-Himalayas 总被引:1,自引:0,他引:1
Mountains occupy 24% of the global land surface area and are home to 12% of the world’s population. They have ecological,
aesthetic, and socioeconomic significance, not only for people living in mountain areas, but for those living beyond. Mountains
need specific attention for their contribution to global goods and services, especially by developing and implementing mountain
specific policies. Conservation policies have evolved from the protection of charismatic species, to habitat and ecosystem/landscape
conservation, and, finally, to people-oriented conservation approaches. This paper, with particular reference to paradigm
shifts in the Hindu Kush-Himalayan (HKH) region, discusses the evolution of conservation policies, developments in conservation
practices, the status of protected area management, wetland conservation initiatives and the landscape approach, community-based
conservation initiatives, and the convergence of policies and practices. In the HKH region, conservation efforts now adopt
participatory approaches, implement policies of decentralised governance for biodiversity management, and empower local communities
in biodiversity management. The paradigm shift in the policies and practices related to conservation has been gradual and
has included the acceptance of communities as an integral part of national level conservation initiatives, together with the
integration of many global conventions. There are many successful pilots in the HKH region that deserve upscaling by the countries
from the region. Realising the importance of mountains as hotspots of biodiversity, and due to their role as providers of
global goods and services, the Convention on Biological Diversity adopted the Programme of Work on Mountain Biodiversity.
Such a decision specific to mountains provides enormous opportunities for both conservation and development. Recent challenges
posed by climate change need to be integrated into overall biodiversity conservation and management agendas, especially in
mountain areas. The HKH region has been identified as a blank spot for data by the Inter-Governmental Panel on Climate Change,
indicating the need to develop regional database and sharing mechanisms. This is a tall task, but one that holds enormous
opportunity for the HKH countries and institutions with regional mandates to address the emerging challenges of climate change
on biodiversity conservation by reducing scientific uncertainty. 相似文献
9.
IPBES框架下的生物多样性和生态系统服务区域评估及政策经验 总被引:1,自引:0,他引:1
生物多样性和生态系统服务为人类的生计和良好的生活质量奠定了重要基础。然而, 越来越多的研究表明, 生物多样性和生态系统服务在全球范围内的持续下降使自然对人类的贡献大幅降低。多尺度评估能够说明不同尺度下生物多样性的现状, 有利于制定适合区域特点、符合国情的决策建议。2013年12月, 生物多样性和生态系统服务政府间科学政策平台(Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, IPBES)通过第一轮工作方案, 决定开展“区域/次区域生物多样性和生态系统服务评估”(简称“区域评估”), 即评估亚洲-太平洋(简称亚太)、美洲、非洲以及欧洲-中亚四大地理区域的生物多样性和生态系统服务。区域评估报告及其决策者摘要已在IPBES第六次全体会议上(2018年3月, 哥伦比亚麦德林)审议通过。本文概述了四大地理区域的生物多样性的重要性、生物多样性保护领域取得的进展、面临的主要危机和机遇, 探讨了评估对其他国际进程的影响, 综合分析了各区域生物多样性和生态系统服务的特点以及各区域评估结果的差别, 总结了评估的政策经验, 以期为中国的生物多样性保护提供科学参考。 相似文献
10.
全球正在经历第六次物种大灭绝。为了应对生物多样性丧失速率日益加快的严峻挑战, 《生物多样性公约》第十届缔约方大会通过了《生物多样性战略计划》(2011-2020年)及20项爱知生物多样性目标。然而, 2019年IPBES全球评估报告表明, 大部分爱知目标可能无法在2020年实现, 因此, 自然保护需要变革性转变。中国虽然在生物多样性保护方面取得了巨大成就, 提出了系统完整的生态文明制度及建立“以国家公园为主体的自然保护地体系”的目标, 并通过绿盾行动和环保督察提升了生物多样性保护的重要性, 陆地自然保护地覆盖率也已达到18%, 但仍未有效遏制生物多样性下降的趋势, 物种濒危程度持续加剧。尽管生态文明一系列改革已经做出了变革性转变, 中央层面大力推行生物多样性“主流化”的相关政策, 通过机构改革初步解决了自然保护地“九龙治水”的问题, 在国土空间规划和生态保护红线划定中强调了生物多样性保护的重要性, 但是, 生物多样性保护仍然缺乏系统性的解决策略, 需要在不同层面进一步落实“主流化”, 建立完整的法律体系和统一规范高效的保护机制, 保障保护资金, 明确生物多样性在生产、生活空间中的地位, 打通自然保护成果与经济利益的转化渠道。因此, 中国的生物多样性保护应当借助生态文明建设的历史性机遇, 在保护意识、空间布局和保护行动3个方面充分实现变革性的转变, 借助五位一体总体布局, 采用系统化的解决方法, 进一步整合法律、行政、市场、技术和社会等五方面力量, 提出具体的实现路径, 实现保护意识主流化、保护利用统筹化和保护行动全民化等三方面变革性的转变, 形成高效一体化的机制, 以实现“人与自然和谐相处”的生物多样性保护理想状态。 相似文献
11.
Climate change-integrated conservation strategies 总被引:8,自引:1,他引:7
Aim Conservation strategies currently include little consideration of climate change. Insights about the biotic impacts of climate change from biogeography and palaeoecology, therefore, have the potential to provide significant improvements in the effectiveness of conservation planning. We suggest a collaboration involving biogeography, ecology and applied conservation. The resulting Climate Change‐integrated Conservation Strategies (CCS) apply available tools to respond to the conservation challenges posed by climate change. Location The focus of this analysis is global, with special reference to high biodiversity areas vulnerable to climate change, particularly tropical montane settings. Methods Current tools from climatology, biogeography and ecology applicable to conservation planning in response to climate change are reviewed. Conservation challenges posed by climate change are summarized. CCS elements are elaborated that use available tools to respond to these challenges. Results Five elements of CCS are described: regional modelling; expanding protected areas; management of the matrix; regional coordination; and transfer of resources. Regional modelling uses regional climate models, biotic response models and sensitivity analysis to identify climate change impacts on biodiversity at a regional scale appropriate for conservation planning. Expansion of protected areas management and systems within the planning region are based on modelling results. Management of the matrix between protected areas provides continuity for processes and species range shifts outside of parks. Regional coordination of park and off‐park efforts allows harmonization of conservation goals across provincial and national boundaries. Finally, implementation of these CCS elements in the most biodiverse regions of the world will require technical and financial transfer of resources on a global scale. Main conclusions Collaboration across disciplines is necessary to plan conservation responses to climate change adequately. Biogeography and ecology provide insights into the effects of climate change on biodiversity that have not yet been fully integrated into conservation biology and applied conservation management. CCS provide a framework in which biogeographers, ecologists and conservation managers can collaborate to address this need. These planning exercises take place on a regional level, driven by regional climate models as well as general circulation models (GCMs), to ensure that regional climate drivers such as land use change and mesoscale topography are adequately represented. Sensitivity analysis can help address the substantial uncertainty inherent in projecting future climates and biodiversity response. 相似文献
12.
Protected areas (PAs) not only serve as refuges of biodiversity conservation but are also part of large ecosystems and are vulnerable to change caused by human activity from surrounding lands, especially in biodiversity hotspots. Assessing threats to PAs and surrounding areas is therefore a critical step in effective conservation planning. We apply a threat framework as a means of quantitatively assessing local and surrounding threats to different types of PAs with gradient buffers, and to main ecoregions in the Hengduan Mountain Hotspot of southwest China. Our findings show that national protected areas (NPAs) have lower and significantly lower threat values (p<0.05) than provincial protected areas (PPAs) and other protected areas (OPAs), respectively, which indicates that NPAs are lands with a lower threat level and higher levels of protection and management. PAs have clear edge effects, as the proportion of areas with low threat levels decline dramatically in the 5-kilometer buffers just outside the PAs. However, NPAs suffered greater declines (58.3%) than PPAs (34.8%) and OPAs (33.4%) in the 5-kilometer buffers. Moreover, a significant positive correlation was found between the size of PAs and the proportion of areas with low threat levels that they contained in both PAs and PA buffers (p<0.01). To control or mitigate current threats at the regional scale, PA managers often require quantitative information related to threat intensities and spatial distribution. The threat assessment in the Hengduan Mountain Hotspot will be useful to policy makers and managers in their efforts to establish effective plans and target-oriented management strategies. 相似文献
13.
开展生物多样性保护成效对比评估对于合理执行生态补偿机制的转移支付政策,以及进一步促进全国生态保护管理水平的有效提升都具有重要意义。以2015年版《全国生态功能区划》划定的生物多样性保护重要生态功能区为研究对象,采用生物多样性保护成效结构指数,探讨重要生态功能区生物多样性保护成效的区域分异情况。研究结果表明:(1)华南、华东与华中地区重要生态功能区的生态结构参照基准较高,东北地区重要生态功能区居中,较差的重要生态功能区则位于西南和西北地区,说明了全国生态环境本底的区域分异性;(2)西北和西南地区重要生态功能区的保护成效结构指数较高,华中和华南地区居中,而东北和华东地区的保护成效结构指数较低,体现了2015年全国重要生态功能区生物多样性保护成效的空间差异情况;(3)从草原、森林与湿地生物多样性的保护成效结构指数来看,西北与西南地区、东北和西南地区及华东地区的重要生态功能区分别具有较大优势。上述研究结果反映了全国重要生态功能区生物多样性保护成效优劣的空间差异状况,可为政府部门健全生态补偿机制以及制定生态系统恢复方案提供决策参考。 相似文献
14.
Priority areas for the conservation of South African vegetation: a coarse-filter approach 总被引:1,自引:0,他引:1
B. Reyers D. H. K. Fairbanks A. S. Van Jaarsveld M. Thompson 《Diversity & distributions》2001,7(1-2):79-95
Abstract. South Africa has an important responsibility to global biodiversity conservation, but a largely inadequate conservation area network for addressing this responsibility. This study employs a coarse-filter approach based on 68 potential vegetation units to identify areas that are largely transformed, degraded or impacted upon by road-effects. The assessment highlights broad vegetation types that face high biodiversity losses currently or in the near future due to human impacts. Most vegetation types contain large tracts of natural vegetation, with little degradation, transformation or impacts from road networks. Regions in the grasslands, fynbos and forest biomes are worst affected. Very few of the vegetation types are adequately protected according to the IUCN's 10% protected area conservation target, with the fynbos and savanna biomes containing a few vegetation types that do achieve this arbitrary goal. This investigation identifies areas where limited conservation resources should be concentrated by identifying vegetation types with high levels of anthropogenic land use threats and associated current and potential biodiversity loss. 相似文献
15.
Questioning the effectiveness of the Natura 2000 Special Areas of Conservation strategy: the case of Crete 总被引:2,自引:0,他引:2
Panayiotis G. Dimitrakopoulos Dimitris Memtsas Andreas Y. Troumbis 《Global Ecology and Biogeography》2004,13(3):199-207
Aim This study examines the effectiveness of the selected ‘network’ of Natura 2000 Special Areas of Conservation (SACs) at a regional scale in Greece, in terms of its representativeness of plant biodiversity. Location The island of Crete is used as a case study because it is considered to be one of the 10 hotspots for biodiversity in the Mediterranean Basin. Methods Hotspot analysis and complementarity algorithms are used to define priority areas for conservation and calculate their spatial overlap with the Natura 2000 SACs in Crete. Results The various categories of hotspots contain subsamples of plant categories, used for their definition. Spatial overlap among different categories of hotspots, areas of complementary diversity and Natura 2000 SCAs is low. Main conclusions The results show that the Natura 2000 SACs ‘network’ in Crete seems insufficient to ensure satisfactory representation of the regional plant biodiversity elements. 相似文献
16.
Spyros Tsiftsis Ioannis Tsiripidis Vasiliki Karagiannakidou 《Biodiversity and Conservation》2009,18(7):1765-1780
The establishment of a network of reserves is of fundamental importance to the loss of biodiversity. Seven different area
selection methods for the establishment of a reserve network were applied in the present study: (a) 5% cut-off value of the
grid cells with the highest species richness or conservation value, (b) complementarity analysis using as criteria species
richness or conservation value or rarest species richness, and (c) mixed complementarity analysis using as criteria species
richness or conservation value. These methods were applied in the orchid taxa of east Macedonia. The conservation values of
taxa were estimated on the basis of regional rarity, broad-scale rarity, and species specialization. The spatial overlap between
the resulting networks and the Natura 2000 network of the study area was assessed. Furthermore, the efficiency of the latter
network to protect the orchid taxa of the study area was examined. Our results suggest that: (a) a multiscale estimation of
rarity is necessary for the unbiased estimation of species conservation values; (b) species specialization adds valuable ecological
information to the assessment of taxa conservation values; (c) complementarity and mixed complementarity analyses on species
richness or conservation value safeguard all the taxa of the region; (d) complementarity analysis on the basis of the richness
of the rarest species safeguards all the rarest taxa, but not the total number of the remaining taxa; (e) the 5% cut-off value
on species richness or conservation value fails to protect all the taxa of the region, including a large number of the rarest
taxa; and (f) the Natura 2000 network, despite its large coverage in the study area, fails to safeguard all the taxa, including
some of the rarest. 相似文献
17.
阔叶红松林是北温带物种最丰富的地带性群落之一,长白山地区是其在中国范围内的中心分布区。中国政府已建立保护网络(24个自然保护区组成)来保护阔叶红松林及其重要的物种资源,但成效不显著。利用系统保护规划软件C-Plan,以集水区为规划单元,计算保护网络外规划单元的不可替代性值,识别出保护网络外高保护价值空缺,评估现有保护网络与纳入空缺后的优化保护网络的保护效率。研究结果显示,现有保护网络外的高保护价值规划单元呈集中沿山岭分布的特征,现有保护网络使24种物种的生境(共75种)实现其设定的保护目标,其他51种未能实现保护目标,且20种保护对象未能达到其设定保护目标的50%,保护成效低。纳入空缺后的优化保护网络,可使64种保护对象实现保护目标,其余11种保护对象的保护贡献值也不同程度提高,保护成效显著增强。结合人为干扰情况提出三种不同保护策略情景下的优先保护方案,并根据生态威胁强度提出各方案的保护建议,为长白山阔叶红松林保护管理提供决策依据,并为山地生态区保护网络优化研究提供方法指导。 相似文献
18.
Italian north Tyrrhenian regions harbour pure or nearly pure cork oak woodlands towards the NE limit of the species range and the highest proportion of the habitat on mainland Italy, but their distribution, biodiversity and conservation status are still poorly known. Focusing on the key region of Tuscany, we analysed distribution and plant species richness of these forests based on literature and original field data. The habitat covers about 5.730?ha and is strongly fragmented for natural and non-natural reasons, underscoring its relict character. Out of the 420 plant taxa recorded, 19 were listed in IUCN categories at the national or regional level. Taxonomic singularity was especially high at the genus rank. Three neighbouring areas with different soil conditions and forest structure were compared based on field surveys, sample plots and linear transects from dense stands to shrub and herbaceous communities of small openings. The Versegge site showed the highest species richness at the area-scale and the mean diversity at the plot scale, representing a key biotope for the conservation of the habitat. However, the geographic–floristic covariation between the three sites suggested that a network of small areas would be more effective than a single, large area to protect the most significant components of the local cork oak flora. The Lattaia and Terzo areas may play an important role as corridor sites between the four SCIs of the Rete Natura 2000 network including cork oak communities on the Tuscan mainland. Species richness was higher in the stands with lower cork oak basal area, and there was a significant increase in species number along transects reaching openings caused by traditional human activities. A minor anthropic disturbance of traditional type may help to preserve the fine-scale habitat heterogeneity and the biodiversity of the whole ecosystem. 相似文献
19.
There is a global consensus on the fact that human activities are increasingly eroding biodiversity, especially in many ecologically rich regions of the world. Quantifying these biodiversity losses over large administrative areas, along with the impacts of the respective driving factors is necessary for biodiversity conservation. In this study, we used readily available spatial data on infrastructure, fragmentation, and land use together with ecological data on terrestrial arthropods (as species surrogate) to carry out spatial assessment and mapping of biodiversity values in the Western Region of Ghana, a highly degraded part of the West African biodiversity hotspot. Compared with its pristine condition, our results show that the region has a remaining mean species abundance (MSA) of approximately 52%, indicating a loss of 48% due to anthropogenic activities (mainly cocoa and oil palm farming). Areas of national protection (i.e. national parks and forest reserves) did not prove to have much promise for biodiversity conservation in the region since many were found to have low MSA values. Moreover, according to our arthropod data, no areas of high MSA values were found outside protected areas. However, because the thick, continuous, structurally complex canopies of these orchards responsible for the biodiversity loss provide natural connectivity between protected reserves, diversification of understory vegetation and a reduction in the use of agrochemicals particularly weedicides and pesticides may yield significant conservation outcomes. 相似文献
20.
Ecosystem services, i.e., services provided to humans from ecological systems have become a key issue of this century in resource management, conservation planning, and environmental decision analysis. Mapping and quantifying ecosystem services have become strategic national interests for integrating ecology with economics to help understand the effects of human policies and actions and their subsequent impacts on both ecosystem function and human well-being. Some aspects of biodiversity are valued by humans in varied ways, and thus are important to include in any assessment that seeks to identify and quantify the benefits of ecosystems to humans. Some biodiversity metrics clearly reflect ecosystem services (e.g., abundance and diversity of harvestable species), whereas others may reflect indirect and difficult to quantify relationships to services (e.g., relevance of species diversity to ecosystem resilience, cultural value of native species). Wildlife habitat has been modeled at broad spatial scales and can be used to map a number of biodiversity metrics. In the present study, we present an approach that (1) identifies mappable biodiversity metrics that are related to ecosystem services or other stakeholder concerns, (2) maps these metrics throughout a large multi-state region, and (3) compares the metric values obtained for selected watersheds within the regional context. The broader focus is to design a flexible approach for mapping metrics to produce a national-scale product. We map 20 biodiversity metrics reflecting ecosystem services or other aspects of biodiversity for all vertebrate species except fish. Metrics include species richness for all vertebrates, specific taxon groups, harvestable species (i.e., upland game, waterfowl, furbearers, small game, and big game), threatened and endangered species, and state-designated species of greatest conservation need, and also a metric for ecosystem (i.e., land cover) diversity. The project is being conducted at multiple scales in a phased approach, starting with place-based studies, then multi-state regional areas, culminating into a national-level atlas. As an example of this incremental approach, we provide results for the southwestern United States (i.e., states of Arizona, New Mexico, Nevada, Utah, and Colorado) and portions of two watersheds within this region: the San Pedro River (Arizona) and Rio Grande River (New Mexico). Geographic patterns differed considerably among metrics across the southwestern study area, but metric values for the two watershed study areas were generally greater than those for the southwestern region as a whole. 相似文献