Aim Phylogenetic diversity can provide insight into how evolutionary processes may have shaped contemporary patterns of species richness. Here, we aim to test for the influence of phylogenetic history on global patterns of amphibian species richness, and to identify areas where macroevolutionary processes such as diversification and dispersal have left strong signatures on contemporary species richness.Location Global; equal‐area grid cells of approximately 10,000 km2.Methods We generated an amphibian global supertree (6111 species) and repeated analyses with the largest available molecular phylogeny (2792 species). We combined each tree with global species distributions to map four indices of phylogenetic diversity. To investigate congruence between global spatial patterns of amphibian species richness and phylogenetic diversity, we selected Faith’s phylogenetic diversity (PD) index and the total taxonomic distinctness (TTD) index, because we found that the variance of the other two indices we examined (average taxonomic distinctness and mean root distance) strongly depended on species richness. We then identified regions with unusually high or low phylogenetic diversity given the underlying level of species richness by using the residuals from the global relationship of species richness and phylogenetic diversity.Results Phylogenetic diversity as measured by either Faith’s PD or TTD was strongly correlated with species richness globally, while the other two indices showed very different patterns. When either Faith’s PD or TTD was tested against species richness, residuals were strongly spatially structured. Areas with unusually low phylogenetic diversity for their associated species richness were mostly on islands, indicating large radiations of few lineages that have successfully colonized these archipelagos. Areas with unusually high phylogenetic diversity were located around biogeographic contact zones in Central America and southern China, and seem to have experienced high immigration or in situ diversification rates, combined with local persistence of old lineages.Main conclusions We show spatial structure in the residuals of the relationship between species richness and phylogenetic diversity, which together with the positive relationship itself indicates strong signatures of evolutionary history on contemporary global patterns of amphibian species richness. Areas with unusually low and high phylogenetic diversity for their associated richness demonstrate the importance of biogeographic barriers to dispersal, colonization and diversification processes.

BackgroundLarge-scale patterns or trends in species diversity have long interested ecologists. The classic pattern is for diversity (e.g., species richness) to decrease with increasing latitude. Taxonomic distinctness is a diversity measure based on the relatedness of the species within a sample. Here we examined patterns of taxonomic distinctness in relation to latitude (ca. 32–48 °N) and depth (ca. 50–1220 m) for demersal fishes on the continental shelf and slope of the US Pacific coast.Methodology/Principal FindingsBoth average taxonomic distinctness (AvTD) and variation in taxonomic distinctness (VarTD) changed with latitude and depth. AvTD was highest at approximately 500 m and lowest at around 200 m bottom depth. Latitudinal trends in AvTD were somewhat weaker and were depth-specific. AvTD increased with latitude on the shelf (50–150 m) but tended to decrease with latitude at deeper depths. Variation in taxonomic distinctness (VarTD) was highest around 300 m. As with AvTD, latitudinal trends in VarTD were depth-specific. On the shelf (50–150 m), VarTD increased with latitude, while in deeper areas the patterns were more complex. Closer inspection of the data showed that the number and distribution of species within the class Chondrichthyes were the primary drivers of the overall patterns seen in AvTD and VarTD, while the relatedness and distribution of species in the order Scorpaeniformes appeared to cause the relatively low observed values of AvTD at around 200 m.Conclusions/SignificanceThese trends contrast to some extent the patterns seen in earlier studies for species richness and evenness in demersal fishes along this coast and add to our understanding of diversity of the demersal fishes of the California Current.

The biodiversity of aquatic ecosystems is under threat and there is an urgent need to quantify the various facets of biodiversity to assess the conservation value of freshwater ecosystems. The effects of taxonomic relatedness have so far not been taken into account in biodiversity assessments of lake macrophytes. We therefore tested the response of species richness and average taxonomic distinctness (AvTD) of aquatic macrophytes along environmental gradients using linear regression models and Bayesian Information Criterion variable selection method. We selected data from four regions, each with 50–60 lakes, situated in northern Europe (Finland and Sweden) and northern America (Minnesota and Wisconsin). We separately studied all macrophyte species, hydrophytes and helophytes. Species richness and AvTD of aquatic macrophytes were generally negatively related in all regions, although it was not statistically significant. Both biodiversity measures responded to environmental gradients to various degrees among the studied macrophyte groups and regions. Species richness was best explained by alkalinity and lake area in Finland, by elevation, annual mean temperature and total phosphorus in Minnesota, and by alkalinity in Wisconsin. AvTD was best explained by alkalinity, annual mean temperature and total phosphorus in Finland and by alkalinity in Wisconsin. Very weak relationships were found in Sweden. Our findings strongly suggest that complementary indices are needed to indicate more comprehensively the effects of environmental conditions on freshwater biodiversity. Species richness was found to be a better measure than AvTD to account for conservation value in freshwaters. However, further research is required to evaluate the usefulness of AvTD to indicate conservation value (e.g. randomisation tests), because alternative measures are clearly needed for those freshwater taxa lacking complete information on true phylogenetic diversity.

PDF HTML阅读 XML下载 导出引用 引用提醒 山东近海鱼类群落分类多样性 DOI: 10.5846/stxb201306101579 作者: 作者单位: 山东省海洋水产研究所,胶南市海洋与渔业局,烟台市水产研究所,山东省海洋水产研究所,山东省海洋水产研究所 作者简介: 通讯作者: 中图分类号: Q178.53 基金项目: 泰山学者岗位资助项目(TS200651036) Taxonomic diversity of fish assemblages in coastal waters off Shandong Author: Affiliation: Shandong Marine Fisheries Research Institute,,,,Shandong Marine Fisheries Research Institute Fund Project: 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:根据相关文献整理了山东近海鱼类名录,并根据1998-2009年山东近海鱼类调查名录,应用平均分类差异指数(Δ+)和分类差异变异指数(Δ+)研究了鱼类分类学多样性特征。结果表明,山东近海鱼类名录包括2纲28目91科169属225种,1998年调查仅2纲11目41科58属62种,2006年调查为1纲13目41科71属78种,2009年调查为1纲9目32科55属62种。1998年-2009年调查鱼类种类远远低于鱼类名录记录的种数,分类阶元包含指数较低,平均每属包含1.1种。根据山东近海鱼类名录计算鱼类平均分类差异指数为66.1,分类差异变异指数为141.7;1998-2009年历次调查鱼类平均分类差异指数在60.9-62.7之间,分类差异变异指数在65.4-92.3之间。将1998-2009年历次调查鱼类群落分类多样性指数计算值叠加到山东近海鱼类总名录的95%置信漏斗曲线图,结果表明大部分调查值在置信漏斗曲线之外,目前山东近海鱼类分类多样性已大幅下降。 Abstract:Maintaining biological diversity is one of the central goals of global biodiversity and ecosystem management. The coastal waters off Shandong, located in the Yellow and Bohai seas of northern China, are important spawning and feeding grounds for many fishery species, and so play an important role in biodiversity maintenance. Assessing taxonomic diversity provides a new method for measuring and interpreting community relationships in the form of inter-species differences. It can be carried out simultaneously in different regions, habitats or surveys and has been widely used in fish community studies. In this study, index and characters of taxonomic diversity of fishes in the coastal waters off Shandong were examined. First, a list of fish in the study area was established. This list was based on several studies from published literature and was established from surveys conducted during 1998 and 2009. Fish classification and nomenclature was adopted from the Nelson classification system and synonymous species were excluded. Then the taxonomic diversity, including the average taxonomic distinctness (Δ+) and variation in taxonomic distinctness (Δ+), of fish assemblages was calculated based on the list of fish species. Finally, the survey list of fishes was superpositioned into the total list of fishes in the coastal waters off Shandong and the 95% confidence funnel was calculated. Results show that there were 225 species belonging to 2 classes, 28 orders, 91 families and 169 genera in the checklist of fishes in coastal waters off Shandong. In 2006 there were only 2 classes, 11 orders, 41 families, 50 genera in 1998, 1 class, 13 orders, 41 families, 71 genera and 78 species; and in 2009 there were 1 class, 9 orders, 32 families, 55 genera and 62 species. These results show that the numbers of fish species in coastal waters off Shandong declined in surveys taken between 1998 and 2009. Inclusion index at the taxonomic level was low; with usually only a single species in each genus. The average taxonomic distinctness was 66.1 and variation in taxonomic distinctness was 141.7. In surveys taken between 2006 and 2009, the average taxonomic distinctness was between 60.9 and 62.7 and the variation in taxonomic distinctness was between 65.4 and 92.3. The analysis of 95% confidence funnels showed that almost all surveys were lower than the theoretical mean and was out of 95% confidence funnel, which suggests that the diversity of fishes in coastal waters off Shandong has significantly decreased. The inclusion index of fishes in coastal waters off Shandong was in line with the trend that the inclusion index was higher in tropical waters and lower in high-latitude waters. The average taxonomic distinctness value in coastal waters off Shandong was higher than in other continental shelf waters in China. Due to the large numbers of estuaries, bays, and diverse habitats, the coastal waters off Shandong maintain a fish community with many morphological different species and have a high taxonomic diversity. After decades of overfishing, polluting and habitat loss, the species composition has significantly changed and the taxonomic diversity has significantly declined. 参考文献 相似文献 引证文献

Summary1. It is increasingly recognised that adequate measures of biodiversity should include information on the ‘relatedness’ of species within ecological assemblages, or the phylogenetic levels at which diversity is expressed. Taxonomic distinctness measures provide a series of indices to achieve this, which are independent of sample size. Taxonomic distinctness has been employed widely in marine systems, where it has been suggested that this index can provide a reliable measure of anthropogenic impact.2. We tested the behaviour of three related taxonomic distinctiveness indices (Average Taxonomic Distinctness, Δ+; Variation in Taxonomic Distinctness, Λ+; and Total Taxonomic Distinctness, sΔ+) in relation to putative levels of anthropogenic impact in inland waters and their potential utility in environmental monitoring, using an extensive data set for aquatic beetles from the south‐east of the Iberian Peninsula.3. Taxonomic distinctness measures were not able to identify human disturbance effects and there were no clear relationships between these new biodiversity measures and the disturbance level recorded at individual localities. Furthermore, the taxonomic distinctness measures used were apparently less sensitive to the effects of anthropogenic impact than other diversity metrics, such as species richness and rarity.4. We conclude that taxonomic distinctness indices may not always perform as well as other metrics in the assessment of environmental quality. In addition, taxonomic distinctness measure should be interpreted with caution, as their performance and ability to detect anthropogenic disturbance may depend on the phylogenetic structure of sampled taxa within a region, and their evolutionary and ecological history.

Responses of species and phylogenetic diversity of fish communities in the Lancang River to hydropower development and exotic invasions

Although two thirds of the world’s euphausiid species occur in the Indian Ocean, environmental factors influencing patterns in their diversity across this atypical ocean basin are poorly known. Distribution data for 56 species of euphausiids were extracted from existing literature and, using a geographic information system, spatially-explicit layers of species richness and average taxonomic distinctness (AveTD) were produced for the Indian Ocean. Species richness was high in tropical areas of the southern Indian Ocean (0–20° S), and this high richness extended southwards via the Agulhas and Leeuwin boundary currents. In contrast, the land-locked northern Indian Ocean exhibited lower species richness but higher AveTD, with the presence of the monotypic family Bentheuphausiidae strongly influencing the latter result. Generalised additive modelling incorporating environmental variables averaged over 0–300 m depth indicated that low oxygen concentrations and reduced salinity in the northern Indian Ocean correlated with low species richness. Depth-averaged temperature and surface chlorophyll a concentration were also significant in explaining some of the variation in species richness of euphausiids. Overall, this study has indicated that the patterns in species richness in the Indian Ocean are reflective of its many unusual oceanographic features, and that patterns in AveTD were not particularly informative because of the dominance by the family Euphausiidae.

This paper documented the data of fish species systematically collected in the Daya Bay from 1980s on according to Nelson's classification system and analyzed the diversity at different taxonomic levels.The inclusion index at taxonomic level(TINCLi),taxonomic diversity(Δ+ and ∧+),relative abundances(R)and the similarity index(C)at Order and Family levels were used in this paper.TINCLi is used first in this paper.The results indicated that the fish species in the Daya Bay belonged to 22 orders,94 families and 206 genera,and Perciformes is the major order.Analyzed by the inclusion index at taxonomic level,the average numbers of(families,genera,species),(genera,species) and(species) per order,family and genus are(4.27,9.36,14.55),(2.19,3.40) and(1.55),lower than those of the Dongsha Islands and higher than those in the East China Sea Continent Shelf.The values assumed the inverse proportion with the variation of latitude which demonstrated that the taxonomic diversity of fishes in lower-latitude was lower than the higher-latitude.The average taxonomic distinctness Δ+ and the variation in taxonomic distinctness ∧+ of the Daya Bay were tested in this paper by the PRIMER 5.2.The average taxonomic distinctness Δ+ was 62.2,and the variation in taxonomic distinctness ∧+ was 110.0.Compared the Δ+ with those of the East China Sea Continent Shelf and Dongsha Island,the genetic relationship of the composition of fish species in the Daya Bay was closer than the East China Sea Continent Shelf(65.7) and farther than the Dongsha Islands(55.2).Compared with the similarity index at the order level,the composition of fish species in the Daya Bay is similar to the Dongsha Islands,and similar to the East China Sea Continental Shelf at the family level.In order to increase the acquaintance of diversity in Daya Bay,this paper analyzed the composition of fish species at the species level.It can provide reference for the exploitation and conservation of fish species in the waters.

Estimating diversity of modular organisms may be problematic due to actual difficulties in discriminating between ‘individuals’ and quantifying their abundances. Quantitative data, when available, are collected through methods that could preclude the application of classical diversity indices, making comparisons among studies difficult. Taxonomic distinctness indices, such as the ‘Average Taxonomic Distinctness’ (Δ+) and the ‘Variation in Taxonomic Distinctness’ (Λ+) may represent suitable tools in investigating diversity beyond the simple species number. The potential usefulness of such indices has been explored almost exclusively on unitary organisms, neglecting modular ones. In this study, we employed Δ+ and Λ+ to analyse patterns of diversity of epiphytic hydroid assemblages living on Cystoseira seaweeds at a hierarchy of spatial scales, along 800 km of rocky coast (SE Italy). ANOVA on species richness and Λ+ showed no significant difference in sample diversity at the investigated spatial scales. In contrast, there were significant differences at the scale of 10s of km in Δ+. Analyses based on simulations detected significant variations at all spatial scales in Δ+. Such findings underline the potential of Δ+ in highlighting relevant spatial scales of variation in patterns of hydroid diversity. Our results also suggest that the interplay between natural environmental variations and the complex ecological traits of modular organisms might affect taxonomic distinctness indices. We stress the need for further investigations focusing on modular organisms before any generalizations on the use of taxonomic relatedness measures in examining marine biodiversity can be made.

Unlike the traditional diversity indices, taxonomic diversity indices take into account the distances based on morphological or functional properties of species or the distances among the species based on the topology of Linnaean classifications. Various taxonomic diversity measures have been developed, among which the most frequently used are Warwick and Clarke’s taxonomic diversity (Δ), taxonomic distinctness (Δ*), and average taxonomic distinctness (Δ+) indices. These well-known indices are a natural extension of Simpson diversity and use abundance or presence data of the species. More recently, using Deng entropy from the Dempster–Shafer evidence theory, a new taxonomic measure was proposed by Özkan (2018). By employing this new measure, weighted taxonomic diversity (TO), unweighted taxonomic diversity (uTO), weighted taxonomic distinctness ( TO + ), and unweighted taxonomic distinctness ( uTO + ) can be estimated. This study was addressed to compare the estimators (TO, uTO, TO uTO + , and + ) with the most popular traditional diversity measures (Species richness (S), Shannon entropy (H), and Simpson’s diversity index (1 − λ)) and taxonomic diversity measures (taxonomic diversity (Δ), taxonomic distinctness (Δ+), and average taxonomic distinctness (Δ+). For comparisons, correlation analysis and principal component analysis (PCA) were applied using the plant data taken from 107 sample plots from Yazili Canyon Nature Park in Turkey. The results indicated that TO, uTO, TO uTO + , and + have significantly positive correlation with Δ, Δ*, Δ+, S, H, and 1 – λ (p < .01), and all these estimators that are located between taxonomic diversity/distinctness measures (Δ, Δ*, and Δ+) and traditional diversity measures (S, H, and 1-λ) along the ordination diagram of the applied PCA. Thus, Deng entropy-based taxonomic diversity measures seem to represent not only traditional diversity indices but also taxonomic diversity measures. Reinforced estimators (maximum values of TO, uTO, TO uTO + , and + ) were also improved and used in the present study. Acceptable results were provided from computer-generated simulations by using a hypothetical community dataset. All the computations and simulations were performed using a spreadsheet program created by the authors of this paper. The program, TD_ÖMD, can be downloaded from http: //www .kant itati fekol oji.n et/ta kdivo zkan

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.

We tested the efficacy of two biodiversity indices, average taxonomic distinctness and variation in average taxonomic distinctness, for indicating environmental stress in seaweed assemblages from the Bay of Fundy, New Brunswick, Canada. These indices, which measure the average number of taxonomic levels between species in a sample, offer a potential panacea for biomonitoring because their calculation requires only a species list and a regional taxonomic hierarchy, they offer a statistical framework for testing whether assemblages deviate from an expected taxonomic breadth, and previous studies involving animal assemblages have demonstrated an independence from sampling effort. However, our results were not consistent with previously published studies or with our perception of site conditions. Specifically, putatively impacted sites scored above-average taxonomic distinctness values, while sites otherwise regarded as healthy were indicated as environmentally degraded. We also demonstrate that average taxonomic distinctness values can be negatively correlated with species richness, Shannon diversity and with functional diversity. Further, increasing the breadth of the regional species list to which specific sites were compared resulted in a more conservative test of impact. We recommend that a qualitative understanding of how specific biotic assemblages respond to stress is a necessary prerequisite to use the taxonomic distinctness indices for environmental stress assessments.

Abstract. 1. Assessing species richness (SR) and diversity along environmental gradients is important to see whether abiotic differences alter patterns of species distribution and composition.2. We examined distributions of odonate SR, average taxonomic distinctness (ATD) and functional diversity (FD) (using the Shannon Index on proportions of plant‐dependent and non‐dependent species) with elevation and slope provided from an exploratory survey along a transect in the Sierra de Coalcomán Mountains, Michoacán State, Mexico. Adults were collected along both sides of a 500 m stream segment for 6 h day−1 site−1 in each of eight sites, and these species lists were complemented by collecting mature larvae.3. Species richness and FD declined with elevation among windward sites, while ATD increased. Among leeward sites, SR peaked at mid‐elevation, and there was no trend for FD or ATD with elevation. Leeward sites were similar in species composition, whereas windward sites were dissimilar. Slope was correlated with elevation among windward sites, and influenced most variables, but not among leeward sites. FD was negatively correlated with ATD among sites along both aspects. Mean values of SR, ATD and FD between aspects were similar.4. The Energy‐Richness Hypothesis best explained the species distributions along the windward aspect. Local abiotic influences appeared more important in community assembly among windward sites. Among leeward sites, the potential for Mid‐Domain and Rapoport Effects suggest interspecies interactions control community assembly; providing greater potential for expansion of species elevational ranges, and an increase in range expansion of alien and non‐endemic species along this aspect.

As a less time-consuming procedure, subsampling technology has been widely used in biological monitoring and assessment programs. It is clear that subsampling counts affect the value of traditional biodiversity indices, but its effect on taxonomic distinctness (TD) indices is less well studied. Here, we examined the responses of traditional (species richness, Shannon-Wiener diversity) and TD (average taxonomic distinctness: Delta(+), and variation in taxonomic distinctness: Lambda(+)) indices to subsample counts using a random subsampling procedure from 50 to 400 individuals, based on macroinvertebrate datasets from three different river systems in China. At regional scale, taxa richness asymptotically increased with fixed-count size; >= 250-300 individuals to express 95% information of the raw data. In contrast, 'ID indices were less sensitive to the subsampling procedure. At local scale, TD indices were more stable and had less deviation than species richness and Shannon-Wiener index, even at low subsample counts, with >= 100 individuals needed to estimate 95% of the information of the actual Delta(+) and Lambda(+) in the three river basins. We also found that abundance had a certain effect on diversity indices during the subsampling procedure, with different subsampling counts for species richness and TD indices varying by regions. Therefore, we suggest that TD indices are suitable for biodiversity assessment and environment monitoring. Meanwhile, pilot analyses are necessary when to determine the appropriate subsample counts for bioassessment in a new region or habitat tyPe.

We documented the data of fish species systematically collected in southwestern continental Shelf of Nansha Islands according to Nelson's classification system and analyzed the diversity at different taxonomic levels using inclusion index at taxonomic level(TINCLi),taxonomic diversity(△+ and ∧+),relative abundances(Rr) and the similarity index(C) at order and family levels.The results indicated that the fish species in the southwestern continental shelf of Nansha Islands belonged to 20 orders,110 families and 206 genera,and Perciformes is the major order.Analyzed by the inclusion index at taxonomic level,the average number of(families,genera,species),(genera,species) and(species) in per order,family and genus are(5.5,10.30,14.85),(1.87,2.70) and(1.44),respectirvel,higher than the case of East China Sea continent shelf,Daya Bay and Dongsha Islands at order level.The values assumed the inverse proportion with the variation of latitude which demonstrated that the taxonomic diversity of fishes at lower-latitude was lower than that at the higher-latitude.The average taxonomic distinctness △+and the variation in taxo-nomic distinctness ∧+ of the Daya Bay were tested in this paper by the PRIMER5.2.The average taxonomic distinctness △+ was 65.8,and the variation in taxonomic distinctness ∧+was 110.0.Compared the △+ with those of East China Sea continent shelf,Daya Bay and Dongsha Island,the genetic relationship of the composition of fish species in southwestern continental shelf of Nansha Islands was closer to East China Sea continent shelf(65.7) and farther from Dongsha Island(55.2) and Daya Bay(62.2).Based on the similarity index,at the order and family levels,the composition of fish species in southwestern continental shelf of Nansha Islands is similar to the Daya Bay.