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1.
Axioms developed from island biogeography theory (i.e. species–area relationships, effects of fragmentation and isolation) are central to the development of conservation strategy. Within this context, the 'extinction debt' hypothesis brings into question an often assumed relationship between species richness and present-day spatial habitat structure (i.e. extent, fragmentation), suggesting instead that the richness and composition of biological communities may lag behind spatial changes in habitat. We examined evidence for an extinction debt among epiphytic lichens, a highly diverse biological group of significant conservation concern. Using sites in Scotland, we compared epiphyte species richness in smaller-scale habitat units (aspen stands) to larger-scale woodland structure (extent and fragmentation) measured at two spatial scales (1 km2 and 4 km2 ) and for two timeframes, modern (1990s to 2000s) and historic (1860s to 1880s). Species richness was positively related to woodland extent and negatively related to woodland fragmentation; however, richness was explained better by historic woodland structure at a 1-km2 scale, than by modern woodland structure. The results indicate: (1) a coupling of stand-scale epiphyte assembly and dynamics of the wider woodland ecosystem, and (2) a significant lag in the response of epiphyte species richness to habitat spatial structure. However, the effect of spatial habitat structure is different between species groups with contrasting traits. The effect of decreasing woodland extent on epiphyte richness is generally more severe for microlichens (comprising a greater number of rare and specialist species) than the more generalist macrolichens. 相似文献
2.
Ecological Diversity and Biodiversity as Concepts for Conservation Planning: Comments on Ricotta 总被引:3,自引:0,他引:3
Sarkar S 《Acta biotheoretica》2006,54(2):133-140
Ricotta argues against the existence of a unique measure of biodiversity by pointing out that no known measure of α-diversity
satisfies all the adequacy conditions that have traditionally been set for it. While that technical claim is correct, it is
not relevant in the context of defining biodiversity which is most usefully measured by β-diversity. The concept of complementarity provides a closely related family of measures of biodiversity which can be used
for systematic conservation planning. Moreover, these measures cannot be replaced by summary statistics but must rely on inventories
of biodiversity surrogates at candidate sites for conservation. 相似文献
3.
Antonio Terlizzi Marti J. Anderson Stanislao Bevilacqua Simonetta Fraschetti Maria Wodarska-Kowalczuk Kari E. Ellingsen 《Diversity & distributions》2009,15(3):450-458
Aim Virtually all studies exploring the use of taxonomic surrogates in assessing patterns of diversity have focused on clear shifts in the location of samples in multivariate space. The potential use of coarser levels of taxonomic resolution to detect patterns of variability in multivariate space, corresponding to β‐diversity in the case of presence/absence data, remains unexplored. Here we considered five ecological data sets of highly diverse marine molluscan assemblages to test the hypothesis that patterns in compositional heterogeneity would be maintained at coarser levels of taxonomic resolution. Location Italy, Norway, New Zealand and the Arctic. Methods We used multivariate dispersion based on the Jaccard resemblance measure of presence/absence data as a measure of β‐diversity to test the null hypothesis that patterns of heterogeneity in species composition for molluscs would be maintained at coarser levels of taxonomic resolution. Tests to compare β‐diversities among groups (based on distances to centroids and using 9999 permutations) were carried out separately for each of five data sets at the species level and then for each of genus, family, order and class levels. Results Differences in multivariate dispersion at the species level (heterogeneity in the identities of species) were maintained for genera and for families, but not at coarser levels of taxonomic resolution (order or class). These results were consistent across all data sets, despite differences in their spatial scale and extent, geographical location, environmental and habitat features (benthic soft sediments, rocky reefs or kelp holdfasts). Main conclusions These results suggest that either genera or families may be used as effective taxonomic surrogates to detect spatial differences in β‐diversity for molluscs. The use of surrogates can provide considerable sampling efficiencies for biodiversity assessments. We consider, however, that a degree of caution and more work is needed, as heterogeneity at the species level may not be reflected by taxonomic surrogates at smaller spatial scales. 相似文献
4.
Berndt J. van Rensburg Patricia Koleff Kevin J. Gaston Steven L. Chown 《Journal of Biogeography》2004,31(5):843-854
Aim To determine whether patterns of avian species turnover reflect either biome or climate transitions at a regional scale, and whether anthropogenic landscape transformation affects those patterns. Location South Africa and Lesotho. Methods Biome and land transformation data were used to identify sets of transition areas, and avian species occurrence data were used to measure species turnover rates (β‐diversity). Spatial congruence between areas of biome transition, areas of high vegetation heterogeneity, high climatic heterogeneity, and high β‐diversity was assessed using random draw techniques. Spatial overlap in anthropogenically transformed areas, areas of high climatic heterogeneity and high β‐diversity areas was also assessed. Results Biome transition areas had greater vegetation heterogeneity, climatic heterogeneity, and β‐diversity than expected by chance. For the land transformation transition areas, this was only true for land transformation heterogeneity values and for one of the β‐diversity measures. Avian presence/absence data clearly separated the biome types but not the land transformation types. Main conclusions Biome edges have elevated climatic and vegetation heterogeneity. More importantly, elevated β‐diversity in the avifauna is clearly reflected in the heterogeneous biome transition areas. Thus, there is spatial congruence in biome transition areas (identified on vegetation and climatic grounds) and avian turnover patterns. However, there is no congruence between avian turnover and land transformation transition areas. This suggests that biogeographical patterns can be recovered using modern data despite landscape transformation. 相似文献
5.
Johannes Måsviken;Love Dalén;Karin Norén;Fredrik Dalerum; 《Journal of Biogeography》2024,51(11):2184-2197
Mountains are often used to study how environmental factors influence biodiversity. However, we have limited understanding of the processes causing biodiversity variation in mountains and whether such processes vary across trophic levels and spatial scales. The aim of this study was to evaluate (i) whether community assembly processes varied along elevational gradients, (ii) whether there were differences in such variation between primary producers (vascular plants) and secondary consumers (spiders) and (iii) whether there were scale dependencies in any elevational variation in community assembly. 相似文献
6.
VALERIA TRIVELLONE LUCIA POLLINI PALTRINIERI MAURO JERMINI MARCO MORETTI 《Insect Conservation and Diversity》2012,5(1):75-85
Abstract. 1. The effects of the current changes in traditional agricultural practices in the Alps on the biodiversity affecting ecosystem functions and services are little known. Vineyards are among the oldest anthropogenic environments of high cultural and natural value that shape the landscape of large areas in Central and Southern Europe. In several mountain regions of the Alps, vineyards are a valid alternative to the landscape homogenisation that has followed post‐cultural land abandonment and agriculture intensification. Key unanswered questions remain regarding the relative contribution of several factors that influence biodiversity, and the level in management pressure with regard to taxonomic and functional diversity enhancement. 2. To answer these questions, we sampled leafhoppers (Auchenorrhyncha) as a model taxon using different standard techniques along 24 vine transects within 8 vineyard complexes in Southern Switzerland. Each transect included one vine row, vine canopy, its interrow and the adjacent slope; the latter two were permanently grass‐covered. Data were analysed using a four‐step approach. 3. Environment (five variables) and Management (four variables) accounted for most of the variance in the leafhopper assemblage. Pesticide use (insecticide and herbicide) and slope mowing are the most important management predictors of leafhopper species composition. 4. With increasing management pressure (i.e. pesticide and mowing), the number of indicator species and particularly the specialists (i.e. stenotopic and oligotopic species) decreases dramatically. 5. To promote taxonomic and functional complexity of communities in vineyard systems, we suggest low management pressure with moderate use of pesticide and a low intensity regime of slope mowing. 相似文献
7.
在联合国《生物多样性公约》生效30年和《生物多样性》创刊30周年之际, 我们通过问卷调查从281名中国研究人员收集到763个生物多样性相关的研究问题, 通过归纳与整理, 并参考英国生态学会提出的100个生态学基本问题, 从中筛选出30个核心问题。这些问题涉及7个方面: 演化与生态(6个问题)、种群(4个问题)、群落与多样性(7个问题)、生态系统与功能(3个问题)、人类影响与全球变化(4个问题)、方法与监测(4个问题)、生物多样性保护(2个问题)。前5个方面主要聚焦在物种形成、生物多样性维持等的关键过程与机制、生物多样性与生态功能关系、全球变化对生物多样性的影响机制等, 第6方面主要涉及生物监测与预测、数据共享等, 第7方面涉及多样性保护、自然与人类健康关系这两个与公众息息相关的重要话题。这30个问题的筛选难免存在偏颇, 希望能以此为契机, 促进我国生物多样性研究人员对本领域核心问题的深入思考与探讨。 相似文献
8.
Keith S. Summerville Tiffany D. Wilson Joseph A. Veech Thomas O. Crist 《Diversity & distributions》2006,12(1):91-99
Two of the major themes resulting from recent macroecological research are the central roles that body size and niche breadth may play as determinants of species geographical distribution. Unanswered questions, however, linger regarding how similarities in body size or niche breadth affect the allocation of α‐ and β‐diversity across spatial scales. Using data on moth diversity in the eastern deciduous forest of North America, we tested the predictions that smaller‐bodied and diet‐restricted species would have lower levels of α‐diversity within forest stands and greater β‐diversity at higher sampling scales compared to larger or more generalist species. Moths were sampled using a nested sampling design consisting of three hierarchical levels: 20 forest stands, 5 sites and 3 ecoregions. Body size for 492 species was estimated as mean forewing length, and diet breadth was assessed from the published literature. Moth species were then classified according to body size (small or large) or diet breadth (generalist or restricted), and partitioning was conducted on each group. Diversity partitions for large‐ and small‐bodied species yielded similar patterns. When observed diversity components differed from those derived from our null model, a consistent pattern was observed: α‐diversity was greater than expected, β‐diversity among forest stands was less than expected, and β‐diversity among sites and ecoregions was higher than expected. In contrast, diet‐restricted moths contributed significantly less to stand‐level α‐diversity than generalist feeders. Furthermore, specialists contributed to a greater proportion of β‐diversity across scales compared to generalist moths. Because absolute measures of β‐diversity among stands were greater for generalists than for restricted feeders, we suggest that regional β‐diversity of forest moths may be influenced by several possible factors: intraspecific aggregation of diet‐restricted species, local fluctuations in population size of eruptive generalists and small geographical distributions of generalist moths than predicted by the geographical extent of putative host plants 相似文献
9.
《African Journal of Aquatic Science》2013,38(3):295-304
We investigated freshwater gastropod diversity, abundance and distribution in habitats with and without anthropogenic disturbance in two localities, Ndere in the Winam Gulf and Mbita Point, Lake Victoria, Kenya, from May 2002 to January 2004. A total of 133 984 gastropod specimens belonging to 15 species were recorded, 14 from Mbita and 12 from Ndere. Two species, Ferrissia kavirondica and Cleopatra cridlandi, which were recorded only from undisturbed habitats, could be indicators of least disturbed habitats. Water chemistry did differ between fish landing sites and undisturbed habitats at some sampling times, indicating that differences due to human impact do exist, but these are dependent on periods of calm weather. The study shows that anthropogenic disturbances cause ecological changes that can be exploited by some snail species, especially Biomphalaria choanomphala and Melanoides tuberculata, while other species may not tolerate these changes. In order to protect gastropod diversity and avoid dominance of intermediate hosts, such as B. choanomphala, a management plan for the use of these fish landing sites should be developed. This could include rules on how to dispose of fish remnants and other wastes so as to reduce local eutrophication, thereby reducing risks associated with transmission of potential snail-borne diseases. 相似文献
10.
Ecologists have traditionally viewed β-diversity as the ratio between γ-diversity and average α-diversity. More recently, an alternative way of partitioning diversity has been proposed for which β-diversity is obtained as the difference between γ-diversity and average α-diversity. Although this additive model of diversity decomposition is generally considered superior to its multiplicative counterpart, in both models β-diversity is a formally derived quantity without any self-contained ecological meaning; it simply quantifies the diversity excess of γ-diversity with respect to average α-diversity. Taking this excess as an index of β-diversity is a questionable operation. In this paper, we show that a particular family of α-diversity measures, the most celebrated of which is Rao's quadratic entropy, can be adequately used for summarizing β-diversity. Our proposal naturally leads to a new additive model of diversity for which, given two or more sets of plots, overall plot-to-plot species variability can be additively partitioned into two non-negative components: average variability in species composition within each set of plots and the species variability between the set of plots. For conservation purposes, the suggested change of perspective in the summarization of β-diversity allows for a flexible analysis of spatial heterogeneity in ecological diversity so that different hierarchical levels of biotic relevance (i.e. from the genetic to the landscape level) can be expressed in a significant and consistent way. 相似文献
11.
Matthias Grenié;Hugo Gruson; 《Ecography》2023,2023(3):e06585
Functional diversity is widely used and widespread. However, the main packages used to compute functional diversity indices are not flexible and not adapted to the volume of data used in modern ecological analyses. We here present fundiversity, an R package that eases the computation of classical functional diversity indices. It leverages parallelization and memoization (caching results in memory) to maximize efficiency with data with thousands of columns and rows. We also did a performance comparison with packages that provide analog functions. In addition to being more flexible, fundiversity was always an order of magnitude quicker than alternatives. fundiversity aims to be a lightweight, efficient tool to compute functional diversity indices, which can be used in a variety of contexts. Because it has been designed following clear principles, it is easy to extend. We hope the wider community will adopt it and we welcome all contributions. 相似文献
12.
Md Mizanur Rahman Lotanna M. Nneji Adeola C. Adeniyi Jinmin Chen Edem A. Eniang Segun O. Oladipo Omotoso Olatunde Abiodun B. Onadeko Felista Kasyoka Kilunda Adeola O Ayoola Babatunde E. Adedeji Ifeanyi C. Nneji Nelson U. Akwaowo Adiaha A. A. Ugwumba Jie-Qiong Jin Tingting Yin Min-Sheng Peng Caroline Olory Nsikan Eninekit Jing Che 《African Journal of Ecology》2020,58(4):815-827
Despite recent anthropogenic interference, south-eastern (SE) Nigeria historically hosts a myriad of pristine forest habitats that could sustain diverse amphibian assemblages. Currently, land conversion of primary forests through human activities has led to modified habitats, such as agricultural fields and secondary forest. This calls for biodiversity documentation and initiation of conservation plans. However, the dearth of herpetological studies has limited knowledge of the amphibian species richness and distribution patterns in some forest ecosystems of SE Nigeria. Thus, we surveyed two less-explored intact forests in SE Nigeria—Afi Forest Reserve (AFR) and Ikpan forest ecosystem (IFE)—to document the patterns of amphibian diversity and distribution. Specimens were searched for opportunistically using visual and acoustic survey methods. Literature searches were conducted to document additional species that were not encountered. Using the observational records and arrays of diversity indices, the patterns of species richness and abundance across habitat types were evaluated. The result of our study revealed the presence of 30 and 31 amphibian species from AFR and IFE, respectively. Our field collections included two unidentified species (Sclerophrys sp. and Hyperolius sp.) from AFR and one (Phrynobatrachus sp.) from IFE. Analyses revealed high species diversity and richness in forest and swamps compared with the agricultural field and savannah. Given the increased human activities and the antecedent threats to forest ecosystems of SE Nigeria, we offer recommendations for the initiation of conservation plans for these two surveyed localities. 相似文献
13.
- Stump extraction for bio energy is a new forestry activity and before large‐scale implementation occurs, it is important to analyse its consequences. Saproxylic beetles depend on dead trees and stump extraction will reduce the amount of habitat available for this group.
- Early warning signs of impending regional species extinctions were looked for in areas where stump harvest has only been conducted for about 3 years. In a paired design (N = 8), the beetle fauna was sampled in stumps on ordinary clear‐cuts and on clear‐cuts from which stumps had been extracted. Sampling in extraction clear‐cuts was possible because 25% of the stump volume was retained. Samples were collected by bark sieving ten Norway spruce, Picea abies, stumps per clear‐cut.
- In total, 6959 individuals of 46 species were found. Several early warning signs were seen: stump extraction reduced the number of species per stump and per clear‐cut and reduced the species evenness in individual stumps.
- Species at higher trophic levels (predators and fungivores), in particular, suffered negative effects. Stump extraction reduced the number of species of fungivores and facultative predators/fungivores at the clear‐cut level and reduced the relative abundance of predators at the stump level.
- These results indicate that if stumps are extracted from a high proportion of the clear‐cuts in a region, the present recommendations of leaving 15–25% of the stump volume will be insufficient for preserving the beetle fauna in the stumps. Further studies are needed to identify levels of stump retention that do not lead to species loss.
14.
Na Huang Xinyuan Sun Yanfang Song Zhiyong Yuan Weiwei Zhou 《Global Ecology and Biogeography》2023,32(5):633-641
15.
Michael J. Lawes Anthony M. Moore Alan N. Andersen Noel D. Preece Donald C. Franklin 《Ecology and evolution》2017,7(20):8442-8455
Ecosystem restoration can help reverse biodiversity loss, but whether faunal communities of forests undergoing restoration converge with those of primary forest over time remains contentious. There is a need to develop faunal indicators of restoration success that more comprehensively reflect changes in biodiversity and ecosystem function. Ants are an ecologically dominant faunal group and are widely advocated as ecological indicators. We examine ant species and functional group responses on a chronosequence of rainforest restoration in northern Australia, and develop a novel method for selecting and using indicator species. Four sampling techniques were used to survey ants at 48 sites, from grassland, through various ages (1–24 years) of restoration plantings, to mature forest. From principal components analysis of seven vegetation metrics, we derived a Forest Development Index (FDI) of vegetation change along the chronosequence. A novel Ant Forest Indicator Index (AFII), based on the occurrences of ten key indicator species associated with either grassland or mature forest, was used to assess ant community change with forest restoration. Grasslands and mature forests supported compositionally distinct ant communities at both species and functional levels. The AFII was strongly correlated with forest development (FDI). At forest restoration sites older than 5–10 years that had a relatively closed canopy, ant communities converged on those of mature rainforest, indicating a promising restoration trajectory for fauna as well as plants. Our findings reinforce the utility of ants as ecological indicators and emphasize the importance of restoration methods that achieve rapid closed‐canopy conditions. The novel AFII assessed restoration status from diverse and patchily distributed species, closely tracking ant community succession using comprehensive species‐level data. It has wide applicability for assessing forest restoration in a way that is relatively independent of sampling methodology and intensity, and without a need for new comparative data from reference sites. 相似文献
16.
保护行为学: 正在兴起的保护生物学分支学科 总被引:4,自引:0,他引:4
过去的30年里, 人们利用动物行为的进化生物学方法来解决保护实践中遇到的问题, 行为学、行为生态学与保护生物学相结合, 产生了保护生物学的一个新分支学科--保护行为学。保护行为学的研究目的是: 从物种保护实践中发现环境对动物行为的影响以及行为的生态适应性, 并把动物行为学和行为生态学理论应用到物种保护实践中, 从而促进物种保护工作。目前全球有10%的物种濒临灭绝, 生物多样性保护日趋紧迫, 保护行为学的诞生为行为学和保护生物学研究带来了新的机遇, 也表明行为学家和保护生物学家正在担负起挽救濒危物种的使命。不久的将来, 保护行为学及其相关学科将更加繁荣。 相似文献
17.
分子生态学研究与运行多样性保护 总被引:7,自引:1,他引:7
分子生态学的发展揭开了生物多样性保护研究的新篇章,分子技术的应用克服了传统生态学法中的一些难题,如野外调查周期长,分辨率有限,实验条件不易控制等,应用各种分子标记(如:RFLP,VNTR,RAPD,DNA测序等)可以分析种群地理格局和异质种群动态,确定种群间的基因流,研究瓶颈效应对种群的影响以及确定个体间的亲缘关系等等,所有这些研究都是指导物种保护和淑危种群的恢复所必要的,种或品系特异性的分子标记技术能够解决形态分类中的模糊现象,确定基于遗传物质的谱系关系,还可以用来分析近缘种间杂交问题,这些问题的解决有助于确定物种优先保护顺序,选择保护地工,近年来引起重视的主要组织人性复合体(MHC)NDA异分析可能会在研究种群对疾病的易感性第一系列种群特异性问题方面非常有用,随着分子技术的不断发展,会有更多的保护生物学问题得到解决,尤其是结合野外调查统计数据应用多个分子标记对目标种群进行研究,所得到的结果会更精确,更有说服力。 相似文献
18.
人为干扰对风水林群落林下木本植物组成和多样性的影响 总被引:10,自引:0,他引:10
华南地区的风水林是乡村聚落的一种特色林分, 具有守护村庄的象征意义。在过去的数百年中, 风水林在乡村的社会文化习俗的影响下而受到保护, 对当地的生物多样性保育有着重要作用。为揭示人为干扰对风水林的影响, 我们选择广东省东莞市大岭山镇同一林分起源的3个具有相似地形的风水林, 研究了在不同干扰强度下其林下木本植物种类组成和物种多样性。多响应置换过程(multi-response permutation procedures, MRPP)分析表明, 人为干扰显著改变了风水林林下木本植物组成(P = 0.001, A = 0.3886), 沿着干扰由弱至强的梯度呈现出中生性植物减少、阳生性植物递增的趋势。多样性指数变化趋势为重度干扰>中度干扰>轻度干扰, 但没有表现出统计学意义上的差异(P>0.05)。随着干扰强度的增大, 3个风水林群落相互间的林下物种相似性降低, 物种替代率呈增加趋势。双向聚类分析较好地反映出林下物种因受不同人为干扰强度影响而表现出在空间分布上的差异。指示种分析进一步确定了不同干扰强度下具有显著指示值(IV ≥60)的指示种。综合分析表明, 人为干扰有利于阳性物种在风水林内定居生长, 并明显地改变了林下木本植物组成, 但未能引起物种多样性的显著差异。此外, 找出对人为干扰产生关键生态响应的林下指示种, 对增进风水林的生物多样性保育以及生态系统管理有着重要的理论意义和实践价值。 相似文献
19.
Use of β-diversity indices in the study of spatial distribution of species diversity is hampered by the difficulty of applying significance tests. To overcome this problem we used a simulation approach in a study of species turnover of ferns, aroids, bromeliads, and melastomes along an elevational gradient from 1700 m to 3400 m in a species-rich tropical cloud forest of Bolivia. Three parameters of species turnover (number of upper/lower elevational species limits per elevational step, Wilson–Shmida similarity index between adjacent steps) were analysed. Significant species turnover limits were detected at 2000 (± 50) m and 3050 m, which roughly coincided with the elevational limits of the main vegetation types recognized in the study area. The taxon specificity of elevational distributions implies that no single plant group can be used as a reliable surrogate for overall plant diversity and that the response to future climate change will be taxon-specific, potentially leading to the formation of plant communities lacking modern analogues. Mean elevational range size of plant species was 490 m (± 369). Elevational range sizes of terrestrial species were shorter than those of epiphytes. We conclude that our simulation approach provides an alternative approach for assessing the statistical significance of levels of species turnover along ecological gradient without the limitations imposed by traditional statistical approaches. 相似文献
20.
The aim of the study was to assess the effects of fen rewetting on carabid beetle and vascular plant assemblages within riverine fens along the river Peene in north‐eastern Germany. Drained (silage grassland), rewetted (restored formerly drained silage grassland), and near‐natural (fairly pristine) stands were compared. Eighty‐four beetle species (7,267 individuals) and 135 plant species were recorded. The richness of vascular plant species and the number of endangered species were highest on near‐natural fens. Fourteen years of rewetting did not increase plant species numbers compared with drained fens. For carabid beetles, however, species richness and the number of stenotopic species were highest on rewetted fens. Rewetting caused the replacement of generalist carabids by wetland specialists, but did not provide suitable habitat for specialist fen carabids or for plant species of oligo‐ or mesotrophic fen communities. Therefore, raising the water table on fens with nutrient‐rich, degraded peat was not sufficient for restoring species assemblages of intact fens, although water level was the most important environmental factor separating species assemblages. Our study illustrated that insects and plants may respond differentially to restoration, stressing the need to consider different taxa when assessing the efficiency of fen restoration. Furthermore, species assemblages of intact fens could not be restored within 14 years, highlighting the importance of conserving pristine habitat. 相似文献