Traditional Diversity Indices Research Articles

Ecological patterns of intertidal macrofauna across an anthropic gradient on tropical Gulf of Mexico sandy beaches: Insights for assessment

In the context of sandy coastlines under increasing coastal development and squeeze, coupled with the ongoing loss of global diversity, it is crucial to understand the ecological patterns of benthic macrofauna, which plays a key role in the trophic and biogeochemical functional connectivity between land and sea. Here, we assessed differences in the spatiotemporal patterns of macrofauna diversity and production in exposed sandy beaches of the southwestern Gulf of Mexico across a use and modification gradient and its utility as indicators of impacts. We also estimated the sampling effort for a representative species inventory, considering three tidal zones, and longitudinal spatial scales in four beaches twice a year, and locally after an event of great tourist incidence. The traditional diversity indices could not conclusively detect the stress gradient of the macrofauna in these systems. The abundance pattern of macrofauna species in the upper intertidal zone and the greater secondary production at the lower zone of the unmodified beaches could be useful as indicators of ecological integrity in natural beaches with similar morphodynamic conditions. On the contrary, the most disturbed beach exhibited greater instability in terms of its macrofauna temporal variation in the lower zone. We verified that the ecological integrity approach comprising both natural and anthropogenic factors and multiple stressors is a useful tool showing precisely how beach-intensive use and modification induce instability and less resilience of its macrofauna, reflected in the species' distribution by tidal zones, and the secondary production patterns. We also provide the first estimate of the optimal sampling effort required to get a representative inventory of the benthic intertidal macrofauna in sandy beaches of the Western Gulf of Mexico within a gradient.

Species diversity patterns differ by life stages in a pine-oak mixed forest

Natural forests comprise trees of different species and sizes, constituting a “biotic framework”. Although examinations of diversity patterns at various spatial scales are frequently conducted, life stages are rarely accounted for. Pine-oak mixedwood forest is widely distributed around the world and constitutes main forest type in the Nanpan River Basin in southwest China. We established a fixed plot with an area of 100 m × 100 m in an undisturbed forest stand and classified trees according to five life stages based on their diameter at breast height (DBH) and height. Then, we calculated eight traditional diversity indices for each life stage. We found that species richness (R), abundance (N), and three diversity indices first increased and then decreased with increasing life stage. As sampling area increased, R, the Shannon-Wiener index (H') and Simpson’s diversity index (D) first increased quickly, followed by a reduced rate of increase, whereas N showed a linear increase and three evenness indices showed gradual decreases. Global Moran’s I values for each diversity index were small, indicating weak spatial autocorrelation. Both R and N of shrubs and saplings decreased sharply with life stage, with only large trees comprising the later life stages. Our results indicate that species diversity patterns in pine-oak forests, particularly in early successional stages, differ among life stages. The changes contribute to the understanding and conservation of forest biodiversity.

Análisis de la diversidad funcional del estrato herbáceo en un ecosistema de dehesa a partir de datos hiperespectrales "in situ"

El presente trabajo aborda la estimación de la diversidad funcional (FD) del estrato herbáceo en un ecosistema de dehesa mediante datos hiperespectrales obtenidos con un espectro-radiómetro portátil ASD FieldSpec® 3 (Analytical Spectral Devices Inc., Boulder, CO, EE. UU.). Los datos ópticos se correlacionaron con variables biofísicas (área foliar específica (SLA), biomasa aérea (AGB), índice de área foliar (LAI) y contenido de nitrógeno (N%)) e índices de diversidad tradicionales como Shannon y Evenness y otros relacionados con la diversidad funcional como el índice multidimensional de dispersión funcional (FDis) usando como variables predictoras: a) índices de vegetación (VIs) y métodos de regresión simple, y b) bandas espectrales y Partial Least Squares Regression (PLSR). Las correlaciones, especialmente de las variables biofísicas relacionadas con FDis, mejoraron sustancialmente al utilizar información hiperespectral (R2 >0.6, rRMSE <0.1) lo que confirma el interés de la dimensión espectral para estimar la diversidad funcional de un ecosistema complejo como es el caso de los pastizales semi-áridos.

Response of marine amphipods to sediment variables (Chabahar Bay- Iran): A step toward localizing amphipod-based bioindices

Chabahar Bay will undergo industrial and coastal pressures according to the government plan to develop the Makran coasts. Therefore, knowing its biological community as well as their possible interactions with environmental variables, before and after coastal development, is important. The amphipod community structure and their response to the structural and contaminant parameters of the sediment include: granulometry, total organic matter (TOM) overloading, heavy metal contamination based on the Pollution Load Index (PLI) and polycyclic aromatic hydrocarbons (PAHs) during post monsoon season of 2017 were investigated from 19 stations. Traditional diversity and taxonomic distinctness indices were calculated. Multivariate analysis revealed the main role of sediment grain size and depth in shaping amphipod community structure. Consequently, two specific ecological niches were determined: species that prefer non-muddy substrates; and those dwelling in muddy or muddy sandy biotopes. No correlation was found between the Shannon diversity (H’), the average taxonomic distinctness indices (Δ+) together and both with contamination parameters. The Δ+ funnel plot well separated under-stressed stations from the healthy ones. The presence of only Ampelisca congeners in under-stressed stations revealed the tolerant nature as well as species-specific response of the genus to anthropogenic impacts. Considerable tolerant response (P > 0.05, r2 = 0.4) of A. zamboangae to PAHs; A. persicus to TOM were observed. High concentration of nickel (Ni) in the studied area already stated due to erosion of ophiolite units from Makran Mountains. The significant correlation of the recently described Iranian species A. lowryi with Ni assumes that it is a native species that is well adapted to the geological conditions of the seabed. Instead Urothoe platydactyla can be considered as early warning signal for PAHs, TOM, Ni and cadmium (Cd) contamination particularly for non-muddy substrates. Our findings help to localize common biotic indices (e.g. AMBI, BENTIX, and BOPA) for studied area through correctly assignment of amphipods to the sensitive/tolerant ecological groups. Finally, we state that in the current situation of Chabahar Bay, in which no special industrial complexes have been established, any sediment-disrupting activity (i.e. sedimentation, dredging, trawling) affects its amphipod communities more than chemical pollutants.

The Tsallis generalized entropy enhances the interpretation of transcriptomics datasets.

Identifying differentially expressed genes between experimental conditions is still the gold-standard approach to interpret transcriptomic profiles. Alternative approaches based on diversity measures have been proposed to complement the interpretation of such datasets but are only used marginally. Here, we reinvestigated diversity measures, which are commonly used in ecology, to characterize mice pregnancy microenvironments based on a public transcriptome dataset. Mainly, we evaluated the Tsallis entropy function to explore the potential of a collection of diversity measures for capturing relevant molecular event information. We demonstrate that the Tsallis entropy function provides additional information compared to the traditional diversity indices, such as the Shannon and Simpson indices. Depending on the relative importance given to the most abundant transcripts based on the Tsallis entropy function parameter, our approach allows appreciating the impact of biological stimulus on the inter-individual variability of groups of samples. Moreover, we propose a strategy for reducing the complexity of transcriptome datasets using a maximation of the beta diversity. We highlight that a diversity-based analysis is suitable for capturing complex molecular events occurring during physiological events. Therefore, we recommend their use through the Tsallis entropy function to analyze transcriptomics data in addition to differential expression analyses.

Long-term monitoring of community succession in impoundment lake: Responses of macroinvertebrate to South-to-North Water Diversion Project

The East Route operation of the South-to-North Water Diversion Project (SNWDP) in China provides a unique opportunity to explore the effects of large-scale cross-regional water transfer on the benthic macroinvertebrate community. A five-year biomonitoring campaign was carried out in Nansi Lake, one of the typical impoundment lakes along the East Route of SNWDP. Ten environmental variables and benthic macroinvertebrate samples were collected in order to evaluate the impacts of water diversion project and the resilience of macroinvertebrate community temporally and spatially. Impacts were evaluated by using a newly developed Inter-annual Index based γ-diversity as well as α and β diversity ways. Biological metrics decreased in early disturbed stage and increased in recolonized stage, indicating a general degraded-recovered pattern when community suffering disturbance. Community in lakeside suffered greater impacts at early disturbed stage but with stronger resilience in recolonized stage than that in lake region. Redundancy analysis showed significant correlations between community structure and physicochemical variables such as water depth, transparency and pH in normal status while temperature in recolonized stage. Thus, the impacts of water diversion project on benthic macroinvertebrate were primarily induced by the variation of physical characteristics, especially the life history of benthic macroinvertebrate inhabiting lake shore area. Moreover, values of traditional diversity indices were too low to provide visually acceptable results when assessing the community succession under large temporal and spatial scale background. The newly suggested Inter-annual Index based γ-diversity offered advantages than traditional indices when assessing the interannual succession of benthic community.

Response of traditional and taxonomic distinctness diversity indices of benthic macroinvertebrates to environmental degradation gradient in a large Chinese shallow lake.

A variety of biodiversity metrics are available to assess the quality of aquatic ecosystems. However, different types of metrics perform with considerable variation and provide various information involved in ecosystem conditions. Taxonomic distinctness (TD) indices have been recommended as desirable measures for assessing environmental degradation, but their utility based on lake macroinvertebrates is still largely unknown. Here, we evaluated the response of traditional and taxonomic distinctness diversity indices (the average taxonomic distinctness, Δ+, and variation in taxonomic distinctness, Λ+) of benthic macroinvertebrates to environmental degradation gradient in Lake Taihu, the third largest freshwater lake in China. Benthic assemblages responded markedly to human disturbances, with significance among-region differences in community composition throughout four seasons. The traditional biodiversity indices (Shannon-Wiener diversity and Pielou's evenness) showed high sensitivity in discriminating anthropogenic impacts, with highest values in macrophytic region but lowest values in eutrophic region. In contrast, Δ+ and Λ+ did not perform well in distinguishing sites subjected to different disturbance levels. The Pearson correlation and multiple regression analysis both indicated that traditional biodiversity metrics (Shannon-Wiener diversity, taxon richness, and Pielou's evenness) responded more readily to water quality variables (Secchi depth, electrical conductivity, and comprehensive trophic level index) than Δ+ and Λ+. Despite the weak correlations between TD indices of benthic macroinvertebrates and water quality in the present study, we suggest that the TD indices should still be considered in bioassessment programs because they provide useful complementary information on traditional diversity indices.

European biodiversity assessments in livestock science: A review of research characteristics and indicators

Developments in agriculture are a main driver for biodiversity loss, in which livestock play a major role through pastures and feed crop cultivation. Addressing biodiversity loss is challenging due to the broad definition of and the multitude of indicators for biodiversity. We reviewed scientific literature assessing effects of livestock on biodiversity in Europe, to provide an overview of general characteristics of these studies and their indicators for biodiversity. The search was performed in SCOPUS and Web of Science and yielded 857 records after deduplication, which was narrowed down to 131 articles that assessed biodiversity impacts of livestock in Europe. Analysis of these articles focused on general characteristics of the research (i.e. context, scale, species, function of livestock, approach), indicators used, and the general conclusion regarding the impact of livestock on biodiversity. The majority of articles studied biodiversity in France, UK, Italy, Germany and Spain; and studied the direct impact of grazing cattle and sheep on biodiversity at field scale. Indirect impacts of livestock on biodiversity through feed production were assessed in few studies. In about one third of the studies, the function of livestock was not related to food production, but to conservation of open landscapes through grazing. We found a large variety of indicators used to assess the impact of livestock on biodiversity. The indicators were divided in seven clusters: 1) DNA, breeds, populations, 2) abundance and richness, 3) traditional diversity indices, 4) novel diversity indices, 5) composition and function, 6) structure and habitats, and 7) qualitative scoring systems. The majority of studies included the indicators abundance and richness, although studies differed in the plant or animal species studied. Indicators used differed across scales and between functions of livestock. Studies with a conservation function of livestock more often used indicators from clusters 5 and 6 than studies with a food production function. A positive impact of livestock on biodiversity was often found in studies with a conservation function, whereas a negative impact of more intensive livestock was often found in studies with a food production function. The identified indicators for biodiversity were connected to different assumptions and values, and therefore answer different questions and present different conclusions regarding the state of biodiversity. This review provides insight in biodiversity assessments of livestock across scales and purposes; highlights that few studies linked livestock to their indirect impacts on biodiversity; and stresses that one should be critical about the indicators used for biodiversity.

Responses of the macroinvertebrate taxonomic distinctness indices of lake fauna to human disturbances in the middle and lower reaches of the Yangtze river

Abstract In recent decades, floodplain lakes have been among the most endangered ecosystems in the world due to human activities, and they are experiencing severe degradation in ecological function and declines in biodiversity. Previous studies have mostly concentrated on the effects of human disturbances on the traditional taxonomic structure of aquatic communities, but little is known about the responses of other facets of biodiversity measures (e.g., phylogenetic relatedness) to anthropogenic impacts. Here, we examined the effectiveness of species richness and taxonomic distinctness (TD) indices (the average taxonomic distinctness, Δ+, and variation in taxonomic distinctness, Λ+) in determining anthropogenic effects based on four datasets of macroinvertebrate communities in 31 shallow lakes in the Yangtze floodplain. The species composition and number of entire taxa and three subsets (mollusk-, insect- and oligochaete-only taxa) were all significantly different among the five lake groups, with the highest species richness in the river-connected lakes, followed by the oxbow, macrophytic, macrophytic-algal transition and algal lakes. For the TD indices, only the Λ+ of entire taxa showed clear differences among lake groups, with the highest values in the algal lakes and the lowest values in the river-connected lakes. However, the TD indices based on the other three datasets showed no differences and did not clearly reveal the degree of anthropogenic disturbances as we expected. However, the spatial pattern of species richness was largely influenced by lake area rather than by water quality. In contrast, the TD indices were insensitive to lake area and responded more readily to water quality than species richness. We proposed that the TD indices provided a useful complement to traditional diversity indices (e.g., species richness) and could be considered as a potential bioassessment metric for detecting the environmental degradation level of freshwater lakes.

厦门湾大型底栖动物分类学多样性指数及分类充分性

PDF HTML阅读 XML下载 导出引用 引用提醒 厦门湾大型底栖动物分类学多样性指数及分类充分性 DOI: 10.5846/stxb201708121452 作者: 作者单位: 国家海洋局第三海洋研究所,国家海洋局第三海洋研究所,国家海洋局第三海洋研究所,国家海洋局第三海洋研究所,国家海洋局第三海洋研究所,国家海洋局第三海洋研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点基础研究发展计划（973计划）（2015CB452905）；海洋公益性行业科研专项经费项目（201505008）；国家重点研发计划"典型脆弱生态修复与保护研究"重点专项（2017YFC0506105） Discussion on taxonomic diversity indices and taxonomic sufficiency for macrobenthos in Xiamen Bay Author: Affiliation: Third Institute of Oceanography, State Oceanic Administration,Third Institute of Oceanography, State Oceanic Administration,Third Institute of Oceanography, State Oceanic Administration,Third Institute of Oceanography, State Oceanic Administration,Third Institute of Oceanography, State Oceanic Administration,Third Institute of Oceanography, State Oceanic Administration Fund Project: The National Basic Research Program of China (973 Program) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以厦门湾为研究区域，收集2014-2015年大型底栖动物的调查数据，计算了大型底栖动物的分类学多样性指数，分析了分类学多样性指数与传统生物多样性指数的相关性和依从性，并从多个角度探讨大型底栖动物的分类充分性。结果表明，厦门湾大型底栖动物分类多样性指数（Δ）介于6.04-83.71之间，平均值为68.26，站位分布不均匀；分类差异性指数（Δ*）介于74.27-99.54之间，平均值为84.23；平均分类差异指数（Δ+）、分类差异变异指数（Λ+）的理论平均值分别为86.82、345.0，个别站位落在95%置信区间外，表明局部区域环境受到了一定程度扰动。Δ、Δ*与Margalef指数、Pielou均匀度指数、Shannon-Wiener指数、Simpson指数呈显著相关，而Δ+、Λ+与传统多样性指数间无显著相关；分类学多样性指数可作为传统生物多样性指数的补充。种级、属级和科级的同一多样性指数间呈显著线性相关，拟合度较高（多数R2>0.9）；根据三个分类水平站位的nMDS二维排序图、2-STAGE的相似性和聚类图，种级、属级和科级的群落结构一致性强，属级较种级丢失的信息约8%、科级为20%，因此在条件有限的情况下，大型底栖动物的监测与评价可根据实际的条件和需求适当将生物鉴定放宽至属水平。 Abstract:Based on survey data on the macrobenthos community in Xiamen Bay during 2014-2015, the taxonomic diversity indices for macrobenthos were calculated and their correlations with traditional diversity indices were examined. The taxonomic sufficiency was also discussed in several ways. The results showed that the taxonomic diversity index (Δ) ranged from 6.04 to 83.71, with an average of 68.26, and it was not evenly distributed among stations. Taxonomic distinctness (Δ*) was in the range of 74.27-99.54, with an average of 84.23. The theoretical averages of average taxonomic distinctness (Δ+) and variation in taxonomic distinctness (Λ+) were 86.82 and 345.0, respectively, and the results from some stations were beyond the 95% probability funnels, indicating that the environment was to some extend disturbed. Both Δ and Δ* significantly correlated with Margalef richness index, Pielou's evenness index, Shannon-Wiener diversity index, and Simpson diversity index, while Δ+ and Λ+ had no significantly correlation with these traditional diversity indices. The results suggested that taxonomic diversity indices could be supplementary diversity indices additional to those traditional indices. Significantly linear correlations were observed for the diversity index between any two levels among the species, genus, and family levels, with high Goodness of Fit (generally R2 > 0.9). Additionally, the results of the nMDS and 2-STAGE analyses indicated that there was a great consistency in community structure under the species, genus, and family levels; however, compared with the species level, certain information was missed at the genus level (8%) and family level (20%). Therefore, we suggest that macrobenthos can be identified to the genus level rather than the species level for the monitoring and assessing macrobenthos in case that identification to species level is unrealizable. 参考文献 相似文献 引证文献

Functional roles of an engineer species for coastal benthic invertebrates and demersal fish.

Through their tissues or activities, engineer species create, modify, or maintain habitats and alter the distribution and abundance of many plants and animals. This study investigates key ecological functions performed by an engineer species that colonizes coastal ecosystems. The gregarious tubiculous amphipod Haploops nirae is used as a biological model. According to previous studies, the habitat engineered by H. nirae (i.e., Haploops habitat) could provide food and natural shelter for several benthic species such as benthic diatoms belonging to the gender Navicula, the micrograzer Geitodoris planata, or the bivalve Polititapes virgineus. Using data from scientific surveys conducted in two bays, this study explored whether (1) the Haploops sandy‐mud community modifies invertebrate and ichthyologic community structure (diversity and biomass); (2) H. nirae creates a preferential feeding ground; and (3) this habitat serves as a refuge for juvenile fish. Available Benthic Energy Coefficients, coupled with more traditional diversity indices, indicated higher energy available in Haploops habitat than in two nearby habitats (i.e., Sternaspis scutata and Amphiura filiformis/Owenia fusiformis habitats). The use of isotopic functional indices (IFIs) indicated (1) a higher functional richness in the Haploops habitat, related to greater diversity in food sources and longer food chains; and (2) a higher functional divergence, associated with greater consumption of a secondary food source. At the invertebrate‐prey level, IFIs indicated little specialization and little trophic redundancy in the engineered habitat, as expected for homogenous habitats. Our results partly support empirical knowledge about engineered versus nonengineered habitats and also add new perspectives on habitat use by fish and invertebrate species. Our analyses validated the refuge‐area hypothesis for a few fish species. Although unique benthic prey assemblages are associated with Haploops habitat, the hypothesis that it is a preferential feeding area was not verified. However, specialist feeding behavior was observed for predators, which calls for further investigation.

The taxonomic distinctness diversity of fish community in Lake Honghu during the past 50 years

基于洪湖1959-2004年鱼类群落状况的调查研究，应用分类学多样性指数分析洪湖鱼类群落分类学多样性的变动. 结果显示：受江湖阻隔及人为干扰加剧等因素影响，洪湖鱼类种、属的数目在1981年表现出下降的趋势，科以上的分类阶元的数目则在1993年之后明显减少. 对洪湖鱼类组成进行NMDS排序，1959、1964和1981年的鱼类群落组成较为类似，1993和2004年的群落组成则发生了较大的变化. 随着时间推移，分类差异性指数Δ⁺表现出先上升后下降的趋势，而变异分类差异性指数Λ⁺则表现出先下降后上升的趋势，表明随着人为干扰的增加，洪湖鱼类群落的分类学进化树的平均路径长度和均匀度发生了不同程度的变化. 零假设模型显示，5个时期的Δ⁺值都位于置信区间内，而1993和2004年的Λ⁺值却位于置信区间的上方，显示分类学进化树的均匀度显著下降. Δ⁺和Λ⁺值的变化提供了与物种数变化所蕴含的不同信息，在多样性评价研究中可以作为经典多样性指数的补充. 洪湖鱼类Λ⁺值随干扰程度的加剧而增加，表明这一指数在多样性保护和评价中具有良好的应用价值.;Based on the published literatures about fish assemblages in Lake Honghu, we measured the long-term changes in two taxonomic diversity indices (average taxonomic distinctness, Δ⁺ and variation in taxonomic distinctness, Λ⁺) at five periods (1959, 1964, 1981, 1993, 2004) during the half past century. The results showed that the numbers of species and genera declined from 1981, whereas the numbers of families and higher taxa decreased from 1993. Non-metric multidimensional scaling analysis based on species composition led to a separation of two groups, one grouping 1959, 1964 and 1981, the other gathering 1993 and 2004. Taxonomic distinctness indices displayed a first increase and subsequent decrease of Δ⁺, and a consistent increase of Λ⁺ through time. The five periods all fell within the 95% confidence interval for Δ⁺, but 1993 and 2004 fell significantly above the confidence interval for Λ⁺, indicating a higher unevenness of the distribution of taxa across the taxonomic tree than random expectations. Δ⁺ and Λ⁺ could provide complementary information about the variability of biodiversity in addition to traditional diversity indices, thus we proposed that taxonomic distinctness indices can be used as promising tools in studies of biodiversity and environmental assessment.

Relations between environmental gradients and diversity indices of benthic invertebrates in lotic systems of northern Italy

Abstract. The relations between environmental gradients, as measured by 19 independent variables, and traditional diversity indices (taxonomic richness, diversity and evenness) of benthic macroinvertebrate communities in the lotic systems of northern Italy were analyzed. Redundancy analysis (RDA) was used to describe the response of taxa to environmental gradients. Diversity indices were analyzed using generalized linear models (GLMs) with explanatory variables the first two major RDA axes. The results from RDA showed that taxa variance is mostly explained by altitude/latitude and combined pollution gradients. Taxonomic richness and diversity was higher in the low polluted upland sites (LPUs) in comparison to high polluted lowland sites (HPLs), suggesting that headwater streams have higher taxonomic richness than downstream reaches. On the other hand, evenness was lower in LPUs, probably due to the dominance of some taxa (e.g., Plecoptera) that are more tolerant of colder conditions.

Biodiversity assessment using next-generation sequencing: comparison of phylogenetic and functional diversity between Nebraska grasslands

Global biodiversity is declining rapidly as a consequence of anthropogenic changes to the environment. Traditional diversity indices such as species richness have been used to assess biodiversity, but recent arguments call for a more comprehensive assessment that includes both phylogenetic and functional diversity (PD and FD, respectively). Many PD metrics have been developed, but few empirical studies have compared metrics across sites with the goal of understanding their application to characterizing biodiversity. In this study, 17 PD metrics, four traditional diversity indices, and one measure of FD were calculated and compared between two Nebraska grasslands. PD metrics were calculated from robust phylogenies estimated from next-generation sequencing data of 45 species. Traditional indices were calculated using species abundance data, and FD was quantified by measuring the phylogenetic signal, K, of specific leaf area (SLA). Results showed that PD metrics and traditional indices were not always correlated, and various PD metrics characterized biodiversity differently. In addition, phylogenies estimated from >80 genes were more robust than single- or dual-gene phylogenies resulting in more reliable PD metrics. K of SLA indicated random trait assembly in all sites. Results suggested that metrics that identify phylogenetic structure and relatedness can provide information to conservation planners about the ability of a community to persist in an unpredictable future. A combination of these results with those of future investigations applying PD and FD metrics to varying communities will support concrete recommendations to conservation planners about how to incorporate these metrics into the selection of priority regions.

Structural and functional indices show similar performance in marine ecosystem quality assessment

Reliable ecosystem quality assessment of marine environments is increasingly important due to mounting pressures attributable to human activities. Biotic indices are widely used in studies to describe communities and indicate the ecological state of systems. This study focuses on benthic macroinvertebrate-based biotic indices for the assessment of ecosystem health. Indices used in ecosystem health assessment in the marine environment have mainly focussed on measuring structural components of the system while more recently the measurement of functional components has been highlighted. In this study the performance of traditional diversity indices based on structural components of benthic macroinvertebrate communities, indices developed for the EU Water Framework Directive, and indices which are based on functional biological traits of species were compared. The results indicated that while functional indices may provide a more detailed assessment of the benthic communities than structural indices, the overall outcome is broadly similar for both types of indices. This suggests measurement of functional indices may be unnecessary for routine monitoring purposes, although they may have value in revealing more specific aspects of change in a system.

Can excluding non-insect taxa from stream macroinvertebrate surveys enhance the sensitivity of taxonomic distinctness indices to human disturbance?

Taxonomic distinctness (TD) indices are increasingly recognized as promising measures of diversity for assessing the quality of aquatic ecosystems. TD indices have a number of desirable properties due to their insensitivity to variations caused by sampling settings (e.g. sampling size and sampling efforts) and natural habitat types. But which TD indices are effective at determining anthropogenic effects is currently under debate. Here, we address this issue by calculating average taxonomic distinctness (Δ+) and variation in taxonomic distinctness (Λ+), the two aspects of TD indices considered to be the most powerful ecological indicators, using datasets of entire macroinvertebrate assemblages, insect-only assemblages and EPT taxa obtained from central Chinese running-water habitats. We examined the performances of TD indices based on the three datasets as ecological indicators in detecting anthropogenic stress, and tested the relationships between three Δ+ and environmental variables including land use and water quality. We found that they were all weakly correlated with traditional diversity indices. In distinguishing reference and disturbed sites, Δ+ of insect taxa performed much better than Δ+ of the entire macroinvertebrate and EPT dataset. In general, three Δ+ were related to land-use and water-quality variables, but particular environmental variables accounting for Δ+ were quite different in three datasets. The Δ+ of insect taxa responded more readily to anthropogenic stress than did that of all macroinvertebrate and EPT taxa. We argue that the widespread distribution of some tolerant non-insect taxa (Oligochaeta and Mollusca) in impaired sites but absence in reference sites adds too much “noisy” information for the entire-taxa TD index to distinguish man-made variation from natural variation. Moreover, using only EPT taxa resulted in lowering the sensitivity of Δ+ because too few taxa at species or higher taxonomic levels were available. Thus, we propose that Δ+ of insect taxa may be a more effective biodiversity measure for estimating anthropogenic disturbance on stream macroinvertebrate assemblages.

Community mean traits as additional indicators to monitor effects of land-use intensity on grassland plant diversity

Semi-natural grasslands, biodiversity hotspots in Central-Europe, suffer from the cessation of traditional land-use. Amount and intensity of these changes challenge current monitoring frameworks typically based on classic indicators such as selected target species or diversity indices. Indicators based on plant functional traits provide an interesting extension since they reflect ecological strategies at individual and ecological processes at community levels. They typically show convergent responses to gradients of land-use intensity over scales and regions, are more directly related to environmental drivers than diversity components themselves and enable detecting directional changes in whole community dynamics. However, probably due to their labor- and cost intensive assessment in the field, they have been rarely applied as indicators so far. Here we suggest overcoming these limitations by calculating indicators with plant traits derived from online accessible databases. Aiming to provide a minimal trait set to monitor effects of land-use intensification on plant diversity we investigated relationships between 12 community mean traits, 2 diversity indices and 6 predictors of land-use intensity within grassland communities of 3 different regions in Germany (part of the German ‘Biodiversity Exploratory’ research network). By standardization of traits and diversity measures, use of null models and linear mixed models we confirmed (i) strong links between functional community composition and plant diversity, (ii) that traits are closely related to land-use intensity, and (iii) that functional indicators are equally, or even more sensitive to land-use intensity than traditional diversity indices. The deduced trait set consisted of 5 traits, i.e., specific leaf area (SLA), leaf dry matter content (LDMC), seed release height, leaf distribution, and onset of flowering. These database derived traits enable the early detection of changes in community structure indicative for future diversity loss. As an addition to current monitoring measures they allow to better link environmental drivers to processes controlling community dynamics.

Comparison of taxonomic diversity indices with traditional diversity indices

Ozet Bu calismada Isparta-Sutculer yoresi'nde bulunan Yazili Kanyon Tabiat parki'ndan alinan 11 ornek alan verisi kullanarak taksonomik tur cesitlilik (TAC) indisleri ile geleneksel tur cesitlilik (GEC) indislerinin hesaplanmasi ve karsilastirilmasi amaciyla gerceklestirilmistir. Her onek alan icin bes GEC (Shannon-Wienner ( ), Simpson , Fisher alfa (a), Margalef (d) indisleri ve tur zenginligi (S)) ve bes TAC (taksonomik cesitlilik ( ), taksonomik mesafe ( ), ortalama taksonomik mesafe ( ),taksonomik mesafe icindeki varyasyon ( ),toplam taksonomik mesafe ( )) indisi hesaplanmistir. Indislerinin birbiri ile iliskilerini belirlemek icin korelasyon analizi uygulanmistir. Analizler sonucunda, GEC indislerinin TAC indisleri ile karsilastirildiginda birbirleri ile cok daha yuksek iliskiler gosterdigi belirlenmistir. Calismada ayrica her cesitlilik indisi grubu icin ve butun cesitlilik indisleri icin temel bilesenler analizi (TBA) uygulanmistir. TBA sonuclarina gore, GEC indislerinin veride coklu baglanti degerini gosteren kappa katsayisi 95,14 olarak bulunurken bu deger TAC indisleri icin 34,63 degerinde kalmistir. Butun indislerin dahil edildigi TBA sonuclarina gore, ozdegeri 1'den ve varyansa katilma orani %10 dan buyuk olan iki bilesen tespit edilmis oluo bu bilesenlerin toplam varyans icindeki orani % 94.62 olarak bulunmustur. Burada butun geleneksel cesitlilik indisleri sadece bilesen 1 ile onemli iliski gostermistir. Taksonomik cesitlilik indislerine gelindiginde; , ve her iki eksenle yuksek korelasyon gosterirken sadece bilesen 1 ile ve ise bilesen 2 ile iliski bulunmustur. Sonuclarin genel degerlendirmesine gore, taksonomik cesitlilik indisleri geleneksel cesitlilik indisleri ile karsilastirildiginda daha genis bir araligi tanimlamaktadir ve butun indisleri en iyi temsil eden indis olarak gorulmektedir. Anahtar kelimeler: Biyocesitlilik, taksonomik cesitlilik, tur cesitliligi, fonksiyonel cesitlilik, yapisal cesitlilik

Taxonomic diversity of fish assemblages in the Changjiang Estuary and its adjacent waters

Taxonomic diversity of fish assemblages in the Changjiang Estuary (Yangtze River Estuary) and its adjacent waters was analyzed based on bottom trawl surveys carried out by R/V Beidou in June, August and October 2006. Four groups of fishes were identified for each survey by the two-way indicator species analysis (TWIA). Taxonomic distinctness, species richness and phylogenetic diversity were used to detect changes in taxonomic structure of fish assemblages. Most dominant fish species mainly belonged to Perciformes, Pleuronectiformes, Clupeiformes, Scorpaeniformes and Tetraodontiformes. Species richness in offshore waters of the survey area was higher than that in the other area. The average taxonomic distinctness value (AvTD, Δ +) of each fish assemblage was close to the average taxonomic distinctness of master list in the Changjiang Estuary (79.9), and had a positive correlation with species richness and Shannon diversity index (H′). A negative correlation was found between variations in taxonomic distinctness (VarTD, Λ +) and traditional diversity indices, which were caused by fish species component that led to longer average path lengths among species. Taxonomic diversity index (Δ) had the similar results with species richness, H′, Simpson diversity index (D) and Pielou’s evenness index (J′). VarTD also kept stable, which further certificated that fish assemblages and ecological environment were in equilibrium. Taxonomic distinctness index (Δ*) was relatively stable in most of fish assemblages, and had higher values in some fish assemblages for a few absolutely dominant species. The present study showed that fish community formed new equilibrium stability in 2006 in the Changjiang Estuary when compared with those in the corresponding months of annual survey from 1985 to 1986. And AvTD in each sampling station was lower than AvTD of master list in the Changjiang Estuary, so some ecological niches were absent in each sampling stations from taxonomic or phylogenetic relationships, these would be helpful to stock natural resource and maintain ecological equilibruim of fish assemblages.

Indices for monitoring biodiversity change: Are some more effective than others?

Abstract Statistically rigorous methods for summarizing and reporting trends in the intactness of biodiversity are a key element of effective biodiversity monitoring programs. There are four major approaches for translating complex monitoring data into easily communicated summary statistics: (1) traditional diversity indices such as species richness and Simpson's diversity, (2) species intactness indices based on occurrence, (3) species intactness indices based on abundance, and (4) multivariate community indices. We use simulated data to evaluate the effectiveness of 13 indices from these four categories based on statistical robustness, sensitivity to errors and noise in the data, ecological relevance, and ease of communication. We show that indices that calculate species intactness using equations like Buckland's arithmetic mean index are the most effective for use in large-scale biodiversity intactness monitoring programs. Traditional diversity indices are unsuitable for monitoring of biodiversity intactness, and multivariate indices can be highly sensitive to errors and noise in the data. Finally, we provide guidelines for the application of these indices in biodiversity intactness monitoring.