species richness

物种丰富度
  • 文章类型: Journal Article
    一个直接的,生物多样性与传统农业景观之间的正相关关系在国家或地区范围内都很明显。它主要受到较高的景观多样性和较少的集约化农业的制约。我们在地块层面(耕地的生产性地块,草原,葡萄园,果园,和非生产性的土地地貌(主要是田野边缘),如梯田斜坡,梯田台阶,堆,成堆的人,和松散的墙壁)在三个传统的农业景观中:山村LiptovskáTeplička,SvätüJur的葡萄园景观,以及赫里奥瓦州山下地区的分散定居点。我们确定了选定的景观生态因子(一组涉及土地利用和管理的因子,农业地貌和救济性质)对植被和选定的无脊椎动物群体(蜘蛛,千足虫,蝗虫,和the)。我们还探讨了保持传统的土地利用和传统的管理是否有助于增强生物多样性。我们发现,管理制度是决定维管植物和所有研究动物群体的物种组成的最重要因素。此外,目前的土地利用和土地地貌特征(类型,骨架内容,连续性)是重要因素。我们对生物多样性与保持传统土地利用和传统管理之间的积极关系的期望是,总的来说,尚未确认:这种关系仅在SvätüJur中发现,用于蜘蛛的生物多样性。
    A direct, positive correlation between biodiversity and the traditional agricultural landscape is evident on the national or regional scale. It is mostly conditioned by higher landscape diversity and less intensive farming. We have carried out research on a detailed scale at plot level (productive plots of arable lands, grasslands, vineyards, orchards, and unproductive agrarian landforms (mostly field margins) such as terraced slopes, terraced steps, heaps, mounds, and unconsolidated walls) in three traditional agricultural landscapes: the mountain village Liptovská Teplička, the vineyard landscape in Svätý Jur, and dispersed settlements in a submontane area in Hriňová. We determined the statistical significance of the impact of the selected landscape ecological factors (a set of factors concerning land use and management, agrarian landforms and relief properties) on the distribution of vegetation and selected invertebrate groups (spiders, millipedes, grasshoppers, and crickets). We also explored whether maintaining traditional land use and traditional management helped to enhance the biodiversity. We found that the management regime is the most important factor determining the species composition of vascular plants and all studied animal groups. Also, present land use and agrarian landforms character (type, skeleton content, continuity) are significant factors. Our expectation of a positive relationship between biodiversity and the maintaining traditional land use and traditional management was, in general, not confirmed: such a relation was only found in Svätý Jur for biodiversity of spiders.
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  • 文章类型: Journal Article
    在不同的空间范围内测量物种丰富度可能具有挑战性,特别是在很大程度上,详尽的物种调查是困难或不可能的。我们的工作旨在确定来自不同空间范围的堆叠生态位模型的物种丰富度估计的可靠性,这些分类群体具有截然不同的环境依赖性和相互作用。要做到这一点,我们为墨西哥北部北美180个已发表的植物区系中的仙人掌科和松科物种建立了生态位模型。我们在代表180个植物区系中的每个植物区系的边界框上叠加或堆叠了所得物种的潜在分布估计值,以生成物种丰富度的预测。总的来说,我们的仙人掌科和松科堆叠模型对物种丰富度的预测效果较差。随着空间范围的大小,观测值和预测值之间的关系显着改善。然而,堆叠模型倾向于高估仙人掌科的丰富度,高估和低估松科的丰富度。仙人掌科堆叠模型显示出比松科更高的灵敏度和更低的特异性。我们得出的结论是,在较小的空间范围内,堆叠的生态位模型可能对物种丰富度的预测效果较差,因此应谨慎使用。也许更重要的是,补偿其局限性或对其可靠性进行校正的能力可能因分类组而异。
    Measuring species richness at varying spatial extents can be challenging, especially at large extents where exhaustive species surveys are difficult or impossible. Our work aimed at determining the reliability of species richness estimates from stacked ecological niche models at different spatial extents for taxonomic groups with vastly different environmental dependencies and interactions. To accomplish this, we generated ecological niche models for the species of Cactaceae and Pinaceae that occur within 180 published floras from North America north of Mexico. We overlaid or stacked the resulting species\' potential distribution estimates over the bounding boxes representing each of the 180 floras to generate predictions of species richness. In general, our stacked models of Cactaceae and Pinaceae were poor predictors of species richness. The relationships between observed and predicted values improved noticeably with the size of spatial extents. However, the stacked models tended to overpredict the richness of Cactaceae and over- and underpredict the richness of Pinaceae. Cactaceae stacked models showed higher sensitivity and lower specificity than those for Pinaceae. We conclude that stacked ecological niche models may be somewhat poor predictors of species richness at smaller spatial extents and should be used with caution for this purpose. Perhaps more importantly, abilities to compensate for their limitations or apply corrections to their reliability may vary with taxonomic groups.
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  • 文章类型: Journal Article
    自然栖息地的碎片化是一个在世界范围内呈指数级增长的过程,是对生物多样性的最大威胁之一。生境破坏和破碎化对景观产生重大影响,也可能影响生态系统,人口,和物种。持续的人为过程可能导致某些物种的栖息地丧失,为他人创造栖息地,减小的补丁大小,增加了补丁之间的距离,这可能导致局部灭绝。我们分析了斑块大小和隔离对Potenza市(意大利南部)周围的Procuspubescens树林中地衣的影响。我们使用半径为10m的圆形图随机抽样了11个具有均匀环境变量的森林斑块;斑块范围从0.3到30公顷。对于每个情节,我们收集了有关附生地衣的存在和丰度的数据。我们使用线性回归和多变量分析在补丁级别进行了分析,寻找对物种丰富度的影响,生命形式,和社区组成。多变量分析用于研究碎裂对地衣植被结构的影响。我们调查了栖息地碎片中地衣物种丰富度的主要预测因素,并得出结论,斑块面积本身是地中海城市周边森林地衣物种丰富度的重要(正)驱动因素。
    The fragmentation of the natural habitat is a process that is exponentially increasing worldwide and represents one of the biggest threats to biological diversity. Habitat destruction and fragmentation have a major impact on landscapes and may also affect ecosystems, populations, and species. The ongoing anthropogenic process can result in habitat loss for some species, habitat creation for others, reduced patch size, and increased distance between patches, which may lead to local extinction. We analyzed the effects of patch size and isolation on lichens in Quercus pubescens woods surrounding the city of Potenza (south Italy). We randomly sampled 11 forest patches with homogeneous environmental variables using circular plots with a 10 m radius; the patches ranged from 0.3 to 30 ha. For each plot, we collected data about presence and abundance of epiphytic lichens. We performed the analyses at the patch level using linear regression and multivariate analysis, searching for effects on species richness, life forms, and community compositions. Multivariate analyses were used to study the effect of fragmentation on the structure of lichen vegetation. We investigated the main predictor of lichen species richness in habitat fragmentations and concluded that patch area per se is an important (positive) driver of lichen species richness in Mediterranean peri-urban forests.
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  • 文章类型: Journal Article
    我们引入了一种新的方法,通过使标记重新捕获方法适应分类数据库的比较来估计可接受的物种多样性。随着时间的推移,分类数据库应该变得更加完整,因此,对其完整性的估计和它所处理的分类单元的已知多样性的误差条将减少。独立的数据库可以相互关联,所以我们用估计的时间过程比较它们来理解相关性的影响。如果后面的估计值明显大于前面的估计值,数据库是正相关的,如果它小得多,它们是负相关的,如果估计大致保持不变,那么相关性已经被平均了。我们通过估计MolluscaBase对于接受的陆生腹足动物名称的完整程度来测试此方法。使用来自独立数据库的随机名字样本,我们确定每个名称是否导致MolluscaBase中接受的名称。2020年8月测试的样本发现,16.7%的测试名称丢失;2021年7月,一个人发现5.3%丢失。MolluscaBase在此期间增长了近3,000种被接受的物种,达到27,050种。估计范围从2021年的28409±365到2020年的29063±771。所有估计都有重叠的95%置信区间,表明数据库之间的相关性不会导致重大问题。超过抽样误差的不确定性增加了475±430种,因此,我们对2021年底公认的陆生腹足动物物种的估计为28,895±630种。这一估计比以前的物种高出4000多个物种。这一估计没有考虑到物种进出同义词的持续流动,新发现,或改变分类方法和概念。陆生腹足动物的物种命名曲线还远未达到渐近线,加上额外的不确定性,这意味着,预测有多少更多的物种可能最终被认可是目前不可行的。我们的方法可用于估计最近软体动物的名称总数(相对于目前接受的名称),已知的软体动物化石的多样性,以及其他门的已知多样性。
    We introduce a new method of estimating accepted species diversity by adapting mark-recapture methods to comparisons of taxonomic databases. A taxonomic database should become more complete over time, so the error bar on an estimate of its completeness and the known diversity of the taxon it treats will decrease. Independent databases can be correlated, so we use the time course of estimates comparing them to understand the effect of correlation. If a later estimate is significantly larger than an earlier one, the databases are positively correlated, if it is significantly smaller, they are negatively correlated, and if the estimate remains roughly constant, then the correlations have averaged out. We tested this method by estimating how complete MolluscaBase is for accepted names of terrestrial gastropods. Using random samples of names from an independent database, we determined whether each name led to a name accepted in MolluscaBase. A sample tested in August 2020 found that 16.7% of tested names were missing; one in July 2021 found 5.3% missing. MolluscaBase grew by almost 3,000 accepted species during this period, reaching 27,050 species. The estimates ranged from 28,409 ± 365 in 2021 to 29,063 ± 771 in 2020. All estimates had overlapping 95% confidence intervals, indicating that correlations between the databases did not cause significant problems. Uncertainty beyond sampling error added 475 ± 430 species, so our estimate for accepted terrestrial gastropods species at the end of 2021 is 28,895 ± 630 species. This estimate is more than 4,000 species higher than previous ones. The estimate does not account for ongoing flux of species into and out of synonymy, new discoveries, or changing taxonomic methods and concepts. The species naming curve for terrestrial gastropods is still far from reaching an asymptote, and combined with the additional uncertainties, this means that predicting how many more species might ultimately be recognized is presently not feasible. Our methods can be applied to estimate the total number of names of Recent mollusks (as opposed to names currently accepted), the known diversity of fossil mollusks, and known diversity in other phyla.
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  • 文章类型: Journal Article
    在快速城市化的地区,发展可持续和有弹性的城市农业对于减少环境污染和确保可重复使用的资源至关重要。这项研究的目的是设计,工具,并分析了中水回用系统对作物生长的影响,净水,和生态。彰化县明岛大学李子湖边附近的模拟实验场,台湾,被选为研究领域。建立了中水回用系统,收集学生宿舍排放的生活污水,土壤滤床和系统中的植物被用来净化污水,为了检测它对水质的影响,土壤,植物生长,全年生态。根据结果,再生水回用系统净化的水符合农业灌溉水质标准。而土壤滤床显示纯净水呈碱性,电导率低,这并不影响植物的生长。在中水回用系统中,水果和叶类蔬菜的种植增加了许多生物的栖息地,共发现13科节肢动物49科。研究表明,中水回用系统不仅可以净化水和促进中水回用,而且可以改善生态并开发食品生产潜力。
    In rapidly urbanized regions, the development of sustainable and resilient urban agriculture is essential to reduce environmental pollution and ensure reusable resources. The purpose of this study was to design, implement, and analyze the effects of reclaimed water reuse systems on crop growth, water purification, and ecology. A simulated experimental field near the side of Li Tse Lake at MingDao University in Changhua County, Taiwan, was chosen as the research field. A reclaimed water reuse system was established to collect domestic sewage discharged from the student dormitory, and a soil filter bed and plants in the system were used to purify the sewage, so as to detect its effects on water quality, soil, plant growth, and ecology throughout the year. According to the results, the water purified by the reclaimed water reuse system met the agricultural irrigation water quality criteria. While the soil filter bed showed that the purified water was alkaline and had low electrical conductivity, this did not affect plant growth. In the reclaimed water reuse system, the cultivation of fruiting and leafy vegetables increased the habitats of a number of organisms, and a total of 49 families of arthropods in 13 orders were found. This study showed that the reclaimed water reuse system could not only purify water and promote water reuse but also improve the ecology and develop the potential for food production.
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  • 文章类型: Journal Article
    几十年来,氮(N)沉积一直在增加,并深刻影响了世界许多地区草地生态系统的结构和功能。然而,氮素沉积对高寒草地的影响记录较少。我们进行了为期3年的田间试验,以确定氮沉积对植物物种丰富度的影响,composition,中国青藏高原高寒草甸的群落生产力。我们发现,3年的氮沉积对这些植物群落参数有深远的影响。N率的增加增加了类动物的优势,并减少了非类动物的存在。物种丰富度与地上生物量成反比。植物种类和官能团组成的变化在很大程度上是与N沉积相关的生产力提高的原因。气候因素也与氮添加相互作用,影响生产力。我们的发现表明,短期的氮沉积可以通过向以草胺为主的群落的组成转移来提高高山草甸的生产力。需要进行长期研究,以确定是否会保持成分的变化和生产率的提高。未来的工作还必须评估植物多样性的减少是否会损害敏感高山草原的长期稳定性和功能。
    Nitrogen (N) deposition has been increasing for decades and has profoundly influenced the structure and function of grassland ecosystems in many regions of the world. However, the impact of N deposition on alpine grasslands is less well documented. We conducted a 3-year field experiment to determine the effects of N deposition on plant species richness, composition, and community productivity in an alpine meadow of the Qinghai-Tibetan Plateau of China. We found that 3 years of N deposition had a profound effect on these plant community parameters. Increasing N rates increased the dominance of graminoids and reduced the presence of non-graminoids. Species richness was inversely associated with aboveground biomass. The shift in plant species and functional group composition was largely responsible for the increase in productivity associated with N deposition. Climatic factors also interacted with N addition to influence productivity. Our findings suggest that short-term N deposition could increase the productivity of alpine meadows through shifts in composition toward a graminoid-dominated community. Longer-term studies are needed to determine if shifts in composition and increased productivity will be maintained. Future work must also evaluate whether decreasing plant diversity will impair the long-term stability and function of sensitive alpine grasslands.
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  • 文章类型: Journal Article
    The Western Ghats (WG) mountain chain in peninsular India is a global biodiversity hotspot, one in which patterns of phylogenetic diversity and endemism remain to be documented across taxa. We used a well-characterized community of ancient soil predatory arthropods from the WG to understand diversity gradients, identify hotspots of endemism and conservation importance, and highlight poorly studied areas with unique biodiversity. We compiled an occurrence dataset for 19 species of scolopendrid centipedes, which was used to predict areas of habitat suitability using bioclimatic and geomorphological variables in Maxent. We used predicted distributions and a time-calibrated species phylogeny to calculate taxonomic and phylogenetic indices of diversity, endemism, and turnover. We observed a decreasing latitudinal gradient in taxonomic and phylogenetic diversity in the WG, which supports expectations from the latitudinal diversity gradient. The southern WG had the highest phylogenetic diversity and endemism, and was represented by lineages with long branch lengths as observed from relative phylogenetic diversity/endemism. These results indicate the persistence of lineages over evolutionary time in the southern WG and are consistent with predictions from the southern WG refuge hypothesis. The northern WG, despite having low phylogenetic diversity, had high values of phylogenetic endemism represented by distinct lineages as inferred from relative phylogenetic endemism. The distinct endemic lineages in this subregion might be adapted to life in lateritic plateaus characterized by poor soil conditions and high seasonality. Sites across an important biogeographic break, the Palghat Gap, broadly grouped separately in comparisons of species turnover along the WG. The southern WG and Nilgiris, adjoining the Palghat Gap, harbor unique centipede communities, where the causal role of climate or dispersal barriers in shaping diversity remains to be investigated. Our results highlight the need to use phylogeny and distribution data while assessing diversity and endemism patterns in the WG.
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  • 文章类型: Journal Article
    研究肠道菌群与溃疡性结肠炎(UC)的相关性,以期为临床治疗提供依据和方法。从30名活动性UC患者和10名健康对照收集新鲜粪便样品。提取来自每个样品的肠道菌群DNA并使用HiSeq平台进行16SrRNA基因测序以鉴定粪便样品中的肠道菌群。UC患者肠道菌群丰富度和多样性明显低于健康对照组(P<0.05)。UC患者的肠道菌群种类与健康对照之间观察到显着差异。协同剂(P<0.01)和厚壁菌(P<0.05),与益生菌Veillonella(P<0.01),UC患者的Ruminococus和coprococus明显低于健康对照组(P<0.05)。此外,与对照组相比,肠道致病菌(P<0.01)和肠道致病菌,包括拟杆菌(P<0.01),大肠埃希菌和梭菌均显著增加(P<0.05)。UC的发病率与肠道菌群的变化显著相关。肠道菌群的变化可能导致肠道菌群多样性的降低或特定肠道菌群的富集。
    The association between intestinal flora and ulcerative colitis (UC) was studied in order to provide a basis and method for clinical treatment. Fresh fecal samples were collected from 30 active UC patients and 10 healthy controls. The intestinal flora DNA from each sample was extracted and 16S rRNA gene sequencing was carried out using HiSeq platform to identify the intestinal flora in fecal samples. The richness and diversity of intestinal flora in UC patients were significantly lower than those in healthy control group (P < 0.05). Significant differences were observed between the intestinal flora-species of UC patients and healthy controls. Synergistetes (P < 0.01) and Firmicutes (P < 0.05), along with probiotics Veillonella (P < 0.01), Ruminococcus and Coprococcus (P < 0.05) in the UC patients were lower than that in the healthy controls significantly. Furthermore, compared with the control group, Tenericutes (P < 0.01) and intestinal pathogenic bacteria, including Bacteroides (P < 0.01), Escherichia and Sutterella (P < 0.05) were significantly increased. The incidence of UC is significantly associated with the changes in intestinal flora. Changes in intestinal flora may lead to a decrease in the diversity of intestinal flora or to the enrichment of a particular intestinal flora.
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  • 文章类型: Letter
    Kwan et al. (2017) published an informative study comparing results obtained by next-generation sequencing (NGS) of mean bacterial genera richness among different life stages, male and female adults, and rearing conditions (field vs. laboratory) for Ixodes pacificus. The current paper examines Kwan et al. (2017) as a case study to provide guidance on statistical design and analysis for estimation of richness, derived from next generation sequencing technology, of the bacterial microbiome in field-collected I. pacificus. Suggestions are provided to further strengthen quantification of microbiome richness in studies in ticks, with focus on sampling design. In-depth treatment is provided of the relative merits of estimating mean richness versus median richness. Research on microbiome diversity in ticks can be made quantitatively rigorous; although, more research on methods is needed.
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  • 文章类型: Journal Article
    Unionicola属的水螨是淡水贻贝的常见寄生虫,生活在宿主的g或地幔上,并将这些组织用作产卵部位。尽管对北美联合贻贝中这种螨虫动物的调查表明,这些螨虫代表了高度多样化的组合,我们对软体动物宿主中Unionicola物种多样性的决定因素知之甚少。本研究探讨了与北美联合贻贝相关的Unionicola组合的寄主多样性与螨多样性之间的关系。本研究结果发现寄主物种丰富度与螨物种丰富度呈显著正相关,越来越多的证据表明,寄主多样性是寄生虫多样性的重要决定因素。近年来,分子序列数据已经发现了unionid贻贝之间的神秘生物多样性,对该组的命名法和系统分类法进行了修订。DNA序列变异也揭示了Unionicola螨虫之间的隐秘物种复合物。总的来说,这些发现表明,本研究的结果可能低估了螨虫及其寄主贻贝的物种丰富度。不幸的是,众所周知,人类的扰动已导致北美贻贝和螨类动物的近期灭绝率很高,并且可能在影响这种寄主-寄生虫系统前进的物种丰富度模式中起重要作用。
    Water mites of the genus Unionicola are common parasites of freshwater mussels, living on the gills or mantle of their hosts and using these tissues as sites of oviposition. Although surveys of this mite fauna among North American unionid mussels indicate that these mites represent highly diverse assemblages, we know very little regarding the determinants of Unionicola species diversity among their molluscan hosts. The present study addresses the relationship between host diversity and mite diversity for Unionicola assemblages associated with unionid mussels of North America. The results of this study found a significantly positive relationship between host species richness and mite species richness, adding to a growing body of evidence that host diversity is an important determinant of parasite diversity. In recent years, molecular sequence data have discovered cryptic biodiversity among unionid mussels, yielding revisions in the nomenclature and systematic taxonomy of the group. DNA sequence variation has also revealed cryptic species complexes among Unionicola mites. Collectively, these findings suggest that the results of the present study may be underestimating species richness among mites and their host mussels. Unfortunately, human perturbations are known to have caused high recent rates of extinction in the mussel and mite faunas of North America and could play a major role in influencing patterns of species richness for this host-parasite system moving forward.
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