Macroinvertebrate frequency data for the RIVPACS III sites in Northern Ireland and some comparisons with equivalent data for Great Britain

1. A total of 313 macroinvertebrate taxa were recorded from the 70 running‐water sites in the R iver I nV ertebrate P rediction A nd C lassification S ystem (RIVPACS III) dataset for Northern Ireland, after the application of a standardization procedure to ensure that all samples were identified to the same taxonomic level. The listing includes a small number of oligochaetes not previously reported from Ireland. The frequency of occurrence of the 313 taxa within the Northern Ireland dataset is also presented. 2. The taxonomic composition and frequency of occurrence of taxa in the Northern Ireland dataset were then compared with the 614 site dataset for Great Britain, which included 637 taxa, and a 75 site subset within Britain at a similar latitude to Northern Ireland with 333 taxa. 3. The macroinvertebrate fauna of Northern Ireland is dominated by taxa recorded at the highest frequencies of occurrence in Britain. Some notable absences are highlighted and, in particular, a small number of lotic mayflies and stoneflies which are common in Great Britain. There is documentary evidence of the introduction by man of a number of non‐insect taxa, either deliberately or by accident. 4. A detailed knowledge of the present composition of the macroinvertebrate fauna of running‐water sites in Northern Ireland, and an active research programme on the potential for new colonists to pose a threat to native species, are important factors in the future conservation of the freshwater fauna. Copyright © 2000 John Wiley & Sons, Ltd.     

Indicator taxa for the conservation of pond invertebrate diversity

• 1. Ponds are a valuable resource for the conservation of freshwater biodiversity, but are often extremely numerous in a given area, making assessment of the conservation value of individual sites potentially time consuming.
• 2. The use of indicator taxa, the species richness of which is representative of total site species richness, may provide one way to improve the efficiency of survey work. However, such indicators are poorly developed for freshwater systems.
• 3. A data set was used describing the occurrence of macroinvertebrate taxa in ponds in Oxfordshire, UK, to assess the extent to which variation in the species richness of selected taxa most consistently represented variation in all other taxa.
• 4. Coenagriidae (Odonata) and Limnephilidae (Trichoptera) reflected the variation in species richness of other taxa most consistently, with Coenagriidae showing the best overall performance as an indicator taxon.
• 5. For both suggested indicator taxa, selection of sites based solely on the presence of at least one species of indicator would represent over 95% of all species recorded across all sites.
• 6. Further investigation in different geographical regions is necessary to establish whether these relationships are consistent over a wider area.

Copyright © 2003 John Wiley & Sons, Ltd.     

Use of ecological niche modelling to predict distributions of freshwater fish species in Kansas

Abstract – An essential innovation in aquatic biodiversity research would be a robust approach to accurately predict species’ potential distributions. In this paper, I conduct an analysis to test the efficacy of ecological niche modelling for predicting fish species’ potential distributions using an artificial‐intelligence algorithm, the Genetic Algorithm for Rule‐Set Prediction (GARP). Models of species’ ecological niches are developed using GARP, and projected onto geography to predict species distributions. To test the validity of this approach, I used freshwater fish distribution data for twelve fish species occurring in Kansas. These taxa were chosen to represent phylogenetic, distribution, and habit diversity. I subset these data by omitting half of the counties from model building, and test models using the omitted counties. Models were tested using Receiver Operating Characteristic (ROC) analyses. Of the species tested, all were statistically significant with the models showing excellent predictive ability. Omission errors across taxa ranged from 0 to 17%. This inferential capacity opens doors to many synthetic analyses based on primary point‐occurrence data.     

湟水河流域秋季大型底栖动物群落结构及关键影响因子识别

开展湟水河干支流大型底栖动物调查研究,为湟水河水生态保护修复提供参考依据。于2020年9月对湟水河流域25个样点进行了样品采集和调查,了解湟水河全流域大型底栖动物群落结构并识别影响其空间分布的关键环境因子。共采集并鉴定出大型底栖动物109（属）种;依据大型底栖动物群落结构相似性,湟水河25个样点在空间上可以分为3组：第1组样点主要分布在中上游支流,该组指示物种为朝大蚊属1种（Antocha sp.）;第2组样点分布比较广泛,中上游干、支流均有,该组的指示物种为四节蜉属1种（Baetis sp.）;第3组样点主要分布在中下游干流,该组指示物种为瑞士水丝蚓（Limnodrilus helveticusi）。大型底栖动物的物种丰度、香农威纳指数、Margalef丰富度指数、四节蜉属1种和瑞士水丝蚓的相对丰度在上下游和干支流之间的空间差异性较大。冗余分析（RDA）结果表明栖息地质量、电导率、亚硝态氮、总磷、浊度和水深是影响湟水河大型底栖动物的关键环境因子。湟水河水生态保护应当更多地关注次生盐化和营养盐污染,加强治理上游过度放牧造成的水土流失和农业面源污染。     

Ecology and conservation status of temporary and fluctuating ponds in two areas of southern England

• 1. A high proportion of ponds are temporary in nature, although the biodiversity value of such sites is still poorly recognized. This work explores the plant and macroinvertebrate communities of 76 temporary and fluctuating water bodies in two regions of southern England (Lizard Peninsula, Cornwall and New Forest, Hampshire) that have retained high pond densities. The ecology and conservation status of sites is examined, and comparisons made with ponds elsewhere in England and Wales.
• 2. Lizard and New Forest ponds supported 119 plant and 165 macroinvertebrate species respectively. Patterns of community similarity for plants and macroinvertebrates were highly concordant, taxa being related in a similar manner to measured environmental variables including pond area, depth, pH and water chemistry.
• 3. Patterns of pond occupancy revealed that most species were locally rare, over half occurring in less than 10% of ponds, and less than 10% being recorded from more than 50% of sites. More than 50% of ponds supported at least one nationally rare plant and almost 75% at least one nationally rare macroinvertebrate. These taxa occupied a wide range of pond types in each region, and did not have predictably different ecologies from common species.
• 4. Comparisons with ponds elsewhere in England and Wales revealed that Lizard and New Forest communities are nationally distinct, being most similar to ponds in areas of low intensity agriculture elsewhere in western Britain. Individual ponds in both regions supported more nationally rare taxa, on average, than ponds sampled in the national survey.
• 5. Ponds in the two areas have high conservation value, both regionally and nationally, supporting almost 75% of the global species richness of temporary ponds sampled across England and Wales. Within each region, many taxa are found in relatively few sites, and effective conservation of pond biodiversity will require a regional management approach.

Copyright © 2008 John Wiley & Sons, Ltd.     

Size and age are important factors for marine sanctuaries: evidence from a decade of systematic sampling in a subtropical marine park

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DNA barcoding of fish eggs collected off northwestern Cuba and across the Florida Straits demonstrates egg transport by mesoscale eddies

Identifying spawning sites for broadcast spawning fish species is a key element of delineating critical habitat for managing and regulating marine fisheries. Genetic barcoding has enabled accurate taxonomic identification of individual fish eggs, overcoming limitations of morphological classification techniques. In this study, planktonic fish eggs were collected at 23 stations along the northwestern coast of Cuba and across the Florida Straits to United States waters. A total of 564 fish eggs were successfully identified to 89 taxa within 30 families, with the majority of taxa resolved to species. We provide new spawning information for Luvarus imperialis (Louvar), Bothus lunatus (Plate Fish), Eumegistus illustris (Brilliant Pomfret), and many economically important species. Data from most sites supported previously established patterns of eggs from neritic fish species being found on continental shelves and oceanic species spawning over deeper waters. However, some sites deviated from this pattern, with eggs from reef‐associated fish species detected in the deep waters of the Florida Straits and pelagic species detected in the shallow, continental shelf waters off the coast of northwestern Cuba. Further investigation using satellite imagery revealed the presence of a mesoscale cyclonic eddy that likely entrained neritic fish eggs and transported them into the Florida Straits. The technique of combining DNA‐based fish egg identification with remotely‐sensed hydrodynamics provides an important new tool for assessing the interplay of regional oceanography with fish spawning strategies.     

天鹅洲长江段底栖动物的群落结构与季节变化

探究长江天鹅洲白鱀豚国家级自然保护区长江段底栖动物的群落结构及季节变化,可为该区域水生生物的保育和管理工作提供基础资料和科学依据。2014-2015年,按季节在干流江段设置16个采样站位,进行底栖动物调查和水质理化指标测定,并同步收集当月水位信息。结果表明,4次调查共检出底栖动物53种,其中水生昆虫28种,软体动物9种,寡毛类9种,甲壳动物4种,其他类群3种,常见种为日本沼虾、钩虾、栉水虱、米虾、河蚬、淡水壳菜、多足摇蚊、环足摇蚊和齿斑摇蚊。底栖动物存在较为明显的季节演替,且种类组成较为简单,以小个体的物种和活动能力较强的甲壳类为主。低水位时,生境异质性的升高有利于底栖动物多样性的增加;而高水位时生境异质性的降低,则对底栖动物的多样性不利。水位的升高以及流量的增大,有利于活动能力较强的甲壳动物生存和扩散。底栖动物的密度、生物量以及多样性处于较低水平,与该河段地处下荆江、河道演变剧烈、生境不稳有关,密度水平与长江中游的沙市、黄石断面接近,表明目前底栖动物密度处于较低水平是一种常态现象。     

A baseline biological survey of the proposed Taputeranga Marine Reserve (Wellington,New Zealand): spatial and temporal variability along a natural environmental gradient

• 1. Four macroalgal, four macroinvertebrate and eight fish species were surveyed at eight sites (three inside, five outside the proposed reserve) over three years before the establishment of the Taputeranga Marine Reserve (MR) on Cook Strait (Wellington, New Zealand). This baseline data set was used to estimate temporal and spatial variability in size and abundance of these taxa, and will be used to quantify taxon‐specific changes in size and abundance once the MR is established.
• 2. Statistically significant differences in size and/or abundance were observed for many taxa among the sites. These differences are consistent with the existence of a natural environmental gradient from the west (entrance to Cook Strait) to the east (Wellington Harbour). This gradient highlights the importance of conducting a pre‐reserve baseline survey at multiple sites and over multiple years to better understand the conservation or fisheries benefits that MRs are expected to deliver.
• 3. Two macroalgal, one macroinvertebrate, and six fish species showed statistically significant seasonal variation in abundance. Subsequent multi‐taxa monitoring needs to include a seasonal component to capture this natural variability.
• 4. This multi‐site and multi‐year data set represents one of the most comprehensive and robust baseline data sets available anywhere in the world. It will be used to quantify the ecological changes associated with a newly established full no‐take marine reserve. Ongoing monitoring will enhance understanding of the sizes and abundances of key taxa, allow a detailed determination of the conservation effects of reserve establishment, and inform management decisions for Wellington's south coast.

Copyright © 2008 John Wiley & Sons, Ltd.     

太湖夏季不同类型湖区浮游植物群落结构及环境解释

2010年9月对太湖不同类型湖区31个站点的浮游植物群落结构进行了调查。结果表明,共检测到120种浮游植物,蓝藻门、绿藻门和硅藻门物种占据了相当大的比例。所有站点都有微囊藻出现,微囊藻是草型湖区和藻型湖区的数量单一优势种,导致31个站点的群落多样性指数值都较低。在环境变量的作用下,31个站点被分为3种类型,即草型湖区(组Ⅰ)、藻型湖区(组Ⅱ)和五里湖(组Ⅲ)。草型湖区物种数和多样性指数较高、浮游植物密度和营养盐浓度较低,总磷(TP)浓度极显著低于藻型湖区(t=-3.84,P=0.001)。在一定浓度范围内,微囊藻密度随着悬浮物(SS)浓度的增大而上升。太湖生态修复应以降低水体悬浮物浓度、提高水体透明度为目标,为草型湖泊生态系统的培植创造条件。     

Effects of extensive bottom cultivation of tropical oyster <Emphasis Type="Italic">Crassostrea belcheri</Emphasis> on benthic invertebrate community structure in Ban Don Bay,Suratthani Province,Southern Thailand

The diversity, distribution, and species richness of benthic invertebrates were examined under extensive bottom cultivation of the tropical oyster Crassostrea belcheri during the summer of 2015 at Ban Don Bay, Suratthani Province, Southern Thailand. Oyster farms that had been operating for 25 years were selected for the study, and four sampling sites were allocated along each transect as (i) at the center of the farm, (ii) inside the farm, (iii) at the farm boundary, and (iv) a reference site. Results indicated that a total of 23 families and 28 species of benthic invertebrate taxa were recorded from the four sampling sites, and the macrobenthic invertebrates inhabiting all study sites consisted mainly of gastropods (11 species), polychaetes (11 species), and bivalves (8 species). No significant differences in total density, diversity index, evenness index, and species richness index of benthic invertebrates were found among each sampling site (P?>?0.05). Significant differences in total nitrogen, nitrate, nitrite, total ammonia, sulfide, total phosphorus, organic matter, and grain sizes of sediment were found among each sampling site, but no significant differences in pH and total nitrogen were found. Among the independent variables analyzed, correlation analysis showed relationships between benthic diversity indices and abiotic variables. There were no clear patterns of differences in the detrimental environmental effects between sampling site locations, which indicated a minimal ecological impact of oyster cultivation.     

Validation of environmental DNA (eDNA) as a detection tool for at‐risk freshwater pearly mussel species (Bivalvia: Unionidae)

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Contrasting changes in freshwater fish assemblages and food webs follow modification of tropical waterways

Fresh waters are increasingly threatened by flow modification. Knowledge about the impacts of flow modification is incomplete, especially in the tropics where ecological studies are only starting to emerge in recent years. Using presence/absence data dated approximately four decades apart (~1966 to ~2010) from 10 tropical rivers, we assessed the changes in freshwater fish assemblage and food web after flow modification. The sites were surveyed with methods best suited to habitat conditions (e.g., tray/push netting for low‐order forest streams, visual surveys for canalised rivers and net casting for impounded rivers). With the presence/absence data, we derived and compared six measures of fish assemblage and food web structure: species richness, proportion of native species, overall functional diversity, native functional diversity, food web complexity and maximum trophic level. We found that changes in community assemblage and food web structure were not generalisable across modification regimes. In canalised sites, species richness and maximum trophic levels were lower in the second time period while the opposite was true for impounded sites. However, proportion of native species was consistently lower in the second time period across modification regimes. Changes in fish assemblages and food webs appear to be driven by species turnover. We recorded 79 cases of site‐specific extirpation and 117 cases of site‐specific establishment. Our data further suggest that turnover in assemblage is again contingent on flow‐modification regime. While the process was stochastic in canalised rivers, benthopelagic species were more likely to be extirpated from impounded rivers where species lost were replaced by predominantly alien fish taxa.     

Quantifying macroinvertebrate taxon richness and abundance in open and forested pool complexes in the Sutherland Flows

1. The aquatic macroinvertebrates of two pool complexes, one open and one forested, in the Sutherland Flows containing temporary, drought sensitive and permanent pools were sampled to establish the most economical sampling for future investigation into the effects of afforestation. 2. Given the variation in pool type and size within each complex, (a) an estimate of the average number of taxa per pool of each type was needed to compare pools of different types, (b) the total number of taxa found in each pool type was needed to allow comparison between sites. 3. Thirty specimens from each pool established the average number of taxa per pool and showed that permanent pools had a higher taxon richness than temporary pools. 4. Four hundred and fifty specimens (and therefore 15 pools with 30 specimens each) were needed to give an estimate of the total number of taxa per pool type. However, the number of samples in some categories was insufficient to allow comparisons to be made between sites and rarefaction was used to make baseline comparisons. 5. Rarefaction suggests that at both sites the permanent pools had highest taxon richness. Rarefaction also indicated there may be slightly higher total invertebrate taxon richness in each pool type at the forested site. Copyright © 1999 John Wiley & Sons, Ltd.     

Estimating intrinsic susceptibility to extinction when little ecological information is available: The case of Neotropical freshwater stingrays (Chondrichthyes: Potamotrygoninae)

Determining the extinction risk of poorly known species is difficult, as data on both their biological traits and the threats to which they are exposed are often not available. Neotropical freshwater stingrays (potamotrygonins) represent such a challenge, as limited ecological data prevent formal assessments. Geographic range size (GRS) was computed for the first time for potamotrygonins (as a longitudinal extent of occurrence measured in km of river length) and, together with two other traits correlated with intrinsic susceptibility to extinction—body size, biological productivity (r_max)—was used to rank potamotrygonins according to their intrinsic susceptibility to extinction. Potamotrygonin GRS was only 6%–7% of that of marine elasmobranchs and is likely to be a significant driver of potamotrygonin extinction risk. The relationship between potamotrygonin GRS and body size differed from the expected triangular theoretical pattern; probably a result of the fragmented nature of freshwater habitats. Using K-medoids clustering, we identified seven groups of species; the most susceptible groups comprised the biggest species such as Potamotrygon brachyura and Paratrygon spp. Intrinsic susceptibility was also highest in the largest hydrographic basins, likely as a result of species with low r_max being more common there. Exposure to anthropogenic threats is highest for the species most intrinsically susceptible to extinction, which consequently have a high-extinction risk. We recommend the use of longitudinal extents of occurrence as standardized measurements of freshwater taxa GRS. Our ranking method, combining observed and predicted traits, may be a useful tool to assess poorly known taxa to assist conservation prioritization.     

张家界大鲵繁殖洞穴外溪冬季大型无脊椎动物

2013年1月与2014年1月对湖南张家界大鲵国家级自然保护区大鲵自然繁殖洞穴外溪大型无脊椎动物群落和水质状况进行了调查。共采集到动物117种,隶属于5门8纲16目59科。其中水生昆虫107种,软体动物3种,甲壳动物2种,环节动物3种,涡虫纲和线虫动物各1种。两年各采样点物种数平均为27种,七眼泉洞穴出水口(S6)物种数最多,为33种,骡子塔洞穴出水口(S1)物种数最少为15种。2年1个月中各采样点大型无脊椎动物密度介于872.2~3511.1 ind/m2,平均密度为1747.6 ind/m~2,水生昆虫为优势类群,相对丰度97.05%,其中,四节蜉(Baetis sp.)、宽基蜉(Choroterpes sp.)、纹石蛾(Hydropsyche sp.)、锯形蜉(Serratella sp.)、扁蜉(Heptagenia sp.)和朝大蚊(Antocha sp.)为最优势的种类,其丰度分别占总丰度的32.27%、9.15%、7.13%、6.61%、6.52%、5.45%;基于Shannon-Wiener指数和BI生物指数的水质评价结果显示,各洞穴出水口溪流中,乌木峪(S3)、院子(S4)和七眼泉(S6)水质最为清洁,骡子塔(S1)和芭茅溪(S7)水质稍差,有轻微污染;功能摄食类群分析结果显示各采样点以收集者(GC)和捕食者(PR)为主要优势类群;K-优势曲线结果表明,除了骡子塔洞穴出水口溪流(S1)受到较重的人为影响外,其他采样点基本保持了较高的物种多样性。从两年调查状况来看,张家界大鲵(Andrias davidianus)自然繁殖洞穴外溪出苗期大型无脊椎动物具有较高的多样性,环境敏感类群优势地位明显,通过估算稚鲵营养容纳量推测,洞穴外溪可为野生稚鲵提供良好的饵料条件,但一些自然繁殖洞穴外溪稚鲵食物可能存在不足的风险,应加强保护区内喀斯特溶洞与大型无脊椎动物群落的保护。     

DNA barcoding reveals clear delineation between spawning sites for neritic versus oceanic fishes in the Gulf of Mexico

We combined research‐vessel cruises of opportunity with DNA barcoding to survey planktonic, percomorph fish eggs at 40 stations distributed across and around the Gulf of Mexico (GoM). The objectives were (a) to determine whether eggs of fishes that are potential candidates for the daily egg production method (DEPM) can be readily barcoded, (b) to identify taxa that are spawning in the GoM, (c) to determine encounter rates for eggs of economically valuable taxa, and (d) to characterize individual egg taxa as being primarily neritic, primarily oceanic, or primarily mixed (i.e., both neritic and oceanic). Of the 1,144 eggs that were individually barcoded, 709 (62%) were definitively identified to species (62 species from 42 families), with an additional 20 taxa identified to genus or subfamily level. The eggs of 15 economically important species were identified, most of which had intermediate encounter rates and moderately dispersed spatial distributions, as indicated by an index of aggregation. SIMPROF analysis of stationwise cluster analysis identified eight significant groups within the 35 stations that yielded percomorph eggs; a corresponding specieswise analysis identified six groups of stations as having a neritic egg community and two groups as having an oceanic community, with a community transition located at the shelf break. Although the neritic and oceanic stations did not share important species, it remains possible that coastal pelagic species have mixed neritic–oceanic distributions. Together, these results indicate DEPM fish‐egg surveys based on DNA barcoding are feasible at the large marine ecosystem scale.     

贵州草海秋季浮游植物群落结构与水质因子的关系

为了探究贵州草海浮游植物群落结构特征及其与水质环境因子的关系,为其水资源保护和可持续发展提供参考依据。于2017年11月(秋季)对贵州草海16个采样点的浮游植物种类组成、细胞密度、优势种及环境因子进行调查,同时利用分层聚类分析、冗余分析(RDA)和主成分分析(PCA)的方法探讨浮游植物群落结构、环境因子、采样点三者之间的关系。结果显示,本次调查共鉴定出浮游植物7门、66属、139种;其中蓝藻门12属、22种,绿藻门28属、69种,硅藻门16属、29种,隐藻门2属、3种,裸藻门4属、11种,甲藻门3属、4种,金藻门1属、1种;其中绿藻为优势门类,占浮游植物总数的49.64%;硅藻次之,占20.86%;蓝藻居第三位,占15.83%,金藻最少,仅占0.72%。调查期间,样点6、7、11、12的叶绿素a含量较高,均高于5.0μg/L,细胞密度也较大,均超过了107个/L。各采样点浮游植物的群落结构聚类分析表明,样点7、11、12聚为一类,其优势门类均为蓝藻,且位于靠近威宁县城的沿岸带。各采样点与环境变量之间的主成分分析(PCA)结果显示,6、7、11、12号采样点主要受营养盐、总溶解固体和盐度的影响,浮游植物与环境因子的冗余分析(RDA)得出蓝藻受营养盐的影响较大。研究表明,威宁县城沿岸带的藻类细胞密度明显高于其它位点,其优势门类为蓝藻,营养盐是导致威宁县城沿岸带藻类细胞密度过高的主要原因。     

茅洲河流域水环境治理工程的生态效应研究

评价水环境治理工程对流域水生态环境的影响,可为茅洲河流域进一步的生态修复工作提出建议。对水环境治理初期(2016年5月)和治理期间(2018年8月)茅洲河流域水生态状况进行调查,选取44个采样点,覆盖茅洲河流域的干流以及主要支流,以获取的样本和水质理化数据,对比分析水质、底栖动物群落、浮游藻类及大型水生植物群落变化。结果显示,治理期间茅洲河流域水体化学需氧量(COD)、氨氮(NH_3-N)和总磷(TP)平均浓度分别降低了41.2%、50.6%和66.7%,溶解氧(DO)平均浓度升高了130.8%;底栖动物群落物种多样性增加了53.6%,耐污种类的密度和优势度降低,并在部分样点新增敏感性较高的蜉蝣目、鞘翅目、毛翅目和半翅目水生昆虫类群。大型水生植物种类和分布范围明显增加,流域内分布有挺水植物24种、沉水植物4种、漂浮植物2种、浮叶植物1种。Palmer藻类污染指数指示为重污染的样点减少了56.3%,中污染样点增加了16.3%,轻污染的样点增加了40.0%。BMWP指数评价结果也有好转,最高得分为49。研究表明,治理后的茅洲河流域水污染程度降低,生态环境状况总体有所好转,但流域生态健康状况仍然较差,需进一步开展系统的流域生态修复工作。     

DNA 条形码在鲱形目鱼类物种鉴定和系统进化分析中的应用

采用PCR特异性扩增获得中国近海鲱形目(Clupeiformes)2科6属7种的48条线粒体COI基因序列,结合从Gen Bank筛选出的4科40属83种的COI基因序列225条,对鲱形目鱼类的COI条形码基因特征、种内与种间遗传距离及其分子系统进化关系进行了分析,探索了DNA条形码技术在辅助鱼类物种鉴定和分类中的适应性。结果表明,4科41属90种273条COI基因序列的平均碱基组成为T:28.3%、C:28.3%、A:24.2%、G:19.2%,碱基组成表现出明显偏倚性。鲱形目鱼类种间的平均遗传距离为0.131,种内平均遗传距离为0.003,种间距离为种内距离的41倍;系统学分析结果显示,97.8%的鱼类在系统进化树上均为单系。可见,鲱形目鱼类DNA条形码符合物种鉴定的要求,且基于COI基因所建的NJ树对物种分类具有较为准确的辨识力。系统进化分析结果表明,COI基因不仅能够解决低阶分类单元的系统进化关系,对于高阶分类单元的系统分析研究结果也有一定参考价值。