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Observer error in vegetation surveys:a review

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Journal of Plant Ecology 2016年第4期9卷 367-379页

作者： lloyd w.morrison Department of Biology Missouri State University901 S.National AvenueSpringfieldMO 65897USA National Park Service Heartland Inventory and Monitoring Program6424 W.Farm Road 182RepublicMO 65738USA

Aims Vegetation sampling employing observers is prone to both inter-observer and intra-observer *** types of errors are common:(i)overlooking error(*** observing species actually present),(ii)misidentification error(*** correctly identifying species)and(iii)estimation error(*** accurately estimating abundance).I conducted a literature review of 59 articles that provided quantitative estimates or statistical inferences regarding observer error in vegetation *** FindingsAlmost all studies(92%)that tested for a statistically significant effect of observer error found at least one significant *** surveys of species composition,mean pseudoturnover(the percentage of species overlooked by one observer but not another)was 10-30%.Species misidentification rates were on the order of 5-10%.The mean coefficient of variation(CV)among observers in surveys of vegetation cover was often several hundred%for species with low cover,although CVs of 25-50%were more representative of species with mean covers of>50%.A variety of metrics and indices(including commonly used diversity indices)and multivariate data analysis techniques(including ordinations and classifications)were found to be sensitive to observer *** of error commonly include both characteristics of the vegetation(*** size of populations,rarity,morphology,phenology)and attributes of the observers(*** fatigue,personal biases,differences in experience,physical stress).The use of multiple observers,additional training including active feedback approaches,and continual evaluation and calibration among observers are recommended as strategies to reduce observer error in vegetation surveys.

关键词： interobserver error intraobserver error misidentification pseudoturnover vegetation sampling

Interobserver error in grassland vegetation surveys:sources and implications

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Journal of Plant Ecology 2020年第5期13卷 641-648页

作者： lloyd w.morrison Sherry A.Leis Michael D.DeBacker Department of Biology Missouri State University901 S.National AvenueSpringfieldMO 65897USA National Park Service Heartland Inventory and Monitoring ProgramWilson’s Creek National Battlefield6424 W.Farm Road 182RepublicMO 65738USA

Aims Observer error is an unavoidable aspect of vegetation surveys involving human *** quantified four components of interobserver error associated with long-term monitoring of prairie vegetation:overlooking error,misidentification error,cautious error and estimation *** also evaluated the association of plot size with pseudoturnover due to observer error,and how documented pseudochanges in species composition and abundance compared with recorded changes in the vegetation over a 4-year *** This study was conducted at Tallgrass Prairie National Preserve,*** sites contained 10 plots;each plot consisted of a series of four nested frames(0.01,0.1,1 and 10 m^(2)).The herbaceous species present were recorded in each of the nested frames,and foliar cover was visually estimated within seven cover categories at the 10 m^(2)spatial scale *** hundred total plots(30 sites)were surveyed,and 28 plots selected at random were resurveyed to assess observer *** surveyors worked in teams of *** Findings At the 10 m^(2)spatial scale,pseudoturnover resulting from overlooking error averaged 18.6%,compared with 1.4%resulting from misidentification error and 0.6%resulting from cautious *** resulting from overlooking error increased as plot size decreased,although relocation error likely played a *** change in species composition over a 4-year interval(excluding potential misidentification error and cautious error)was 30.7%,which encompassed both pseudoturnover due to overlooking error and actual *** a documented overlooking error rate of 18.6%,this suggests the actual change for the 4-year period was only 12.1%.For estimation error,26.2%of the time a different cover class was *** the 4-year interval,46.9%of all records revealed different cover classes,suggesting that 56%of the records of change in cover between the two time periods were due to observer error.

关键词： cautious error estimation error misidentification error observer error overlooking error pseudoturnover

草地植被调查中的观测者误差:物种多样性指标和物种丰度关系的影响

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植物生态学报(英文版) 2023年第4期16卷 36-48页

作者： lloyd w.morrison Sherry A.Leis Michael D.DeBacker Department of Biology Missouri State UniversityMO 65897USA National Park Service Heartland Inventory and Monitoring ProgramWilson’s Creek National BattlefieldMO 65738USA

我们研究了观察者误差对4种常用物种多样性度量的影响:物种丰富度、香农-威纳多样性指数、香农-威纳均匀度指数和辛普森多样性指数。我们还评估了观察者误差如何影响由非度量多维尺度(NMS)排序确定的物种丰度关系的多变量分析得出的推论... 详细信息

我们研究了观察者误差对4种常用物种多样性度量的影响:物种丰富度、香农-威纳多样性指数、香农-威纳均匀度指数和辛普森多样性指数。我们还评估了观察者误差如何影响由非度量多维尺度(NMS)排序确定的物种丰度关系的多变量分析得出的推论。3位不同的植物学家在美国密苏里州和堪萨斯州的两个国家公园对草原植被进行了采样。其中的两名植物学家对相同的地块进行了采样,编制了物种组成清单并估计了叶面覆盖率,然后比较了数据记录的差异。伪转换率(即由于观察者错误导致的表观转换率)在17.1%到22.1%之间,覆盖类别估计的差异在21.5%到30.5%之间。观察者对物种多样性测量值的百分比差异取决于数据的总结方式,但总是<20%,而且通常<10%。基于这些研究结果,与周转指数相比,物种多样性指标受观察者误差的影响相对较小。然而,周转指数包含更多信息,因为它们追踪的是单个物种,而在大多数物种多样性指数中,物种是可以互换的。因此,由于物种多样性指数的计算方式,识别出的错误较少。NMS排序显示,虽然不同观察者对某些地块的描述相似,但观察者对其他地块的记录之间的差异导致排序空间的分离更大。与另一个观察者相比,代表一个观察者记录的点通常在相同方向上在排序空间中移动。

关键词：估计误差观察者误差伪周转率物种多样性度量排序植被调查

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全球红火蚁扩张范围预测

中华卫生杀虫药械 2006年第1期12卷 22-26页

作者： lloyd w.morrison 郑剑宁宋晔晔裘炯良薛新春宁波出入境检验检疫局浙江宁波315012

在众多入侵生物中,外来蚂蚁是最棘手的生物之一.许多蚂蚁种群,尤其是那些热带或亚热带的蚂蚁种群,很容易通过人类的商业活动而被迁移到世界各地(McGlynn,1999).其中一些种类已经被证实对侵入区域的自然动物群体产生了广泛而有害的影响(... 详细信息

在众多入侵生物中,外来蚂蚁是最棘手的生物之一.许多蚂蚁种群,尤其是那些热带或亚热带的蚂蚁种群,很容易通过人类的商业活动而被迁移到世界各地(McGlynn,1999).其中一些种类已经被证实对侵入区域的自然动物群体产生了广泛而有害的影响(如 Vander Meer等,1990;williams,1994;Human和Gordon,1997;Jourdan,1997;Holway,1998;Vanderwoude等,2000的报道).

关键词： williams 预测扩张火蚁全球 Gordon Human 世界各地商业活动

Numerical Modelling of Sediment Particle Transportation on a Navigation Inlet Using the Particle Tracking Model (PTM)

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Open Journal of Civil Engineering 2024年第3期14卷 374-390页

作者： lloyd Ndlovu Zaid Mustafa Department of Civil and Environmental Engineering Jackson State University Jackson MS USA

This paper investigates particle transportation using a numerical model application approach to understand the final fate of suspended sediment particle masses due to a dredging operation in a navigational harbor inlet using PTM (Particle Tracking Model). The investigation applied PTM and simulated particle transportation at a navigational harbor called St Jerome Creek Inlet in Chesapeake Bay in Maryland. The United States Army Corps of Engineers (USACE), Maryland District, designed jetties for the inlet, which, when constructed, would minimize dredging requirements from once in a two-year period to once in a ten-year period. In the meantime, due to the frequent dredging requirements of the inlet, there exists a need to understand the fate of the suspended sediments from the dredging operations to assess the environmental impact on the aquatic environment and the coastal community. This study used PTM to simulate the transportation of sediments in a 30-day period during a dredging operation. Ten sediment source locations were selected as possible sites from which dredged materials could be introduced into the flow system. The model output was analyzed to draw conclusions. Results showed that most suspended sediment particle masses moved from their initial site locations and settled along the shoreline, whilst the sediments that found their way out of the inlet system towards the ocean migrated southward and settled approximately 6 miles at the tip of the mainland. The objective of the study is to track sediment particles from a dredging operation. This would be significant in tracking possible contaminants in an aquatic environment for future environmental management decisions.

关键词： PTM Suspended Sediments Dredging Particle Tracking

Fragipan Horizon Changes Using Annual Ryegrass and Other Admendments

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Open Journal of Soil Science 2024年第6期14卷 388-397页

作者： lloyd Murdock Anastasios Karathanasis Dottie Call Dana L. Dinnes Amitava Chatterjee Department of Plant & Soil Science University of Kentucky Lexington KY USA USDA-ARS National Laboratory for Agriculture and the Environment University Bldg Ames IA USA

A greenhouse experiment was conducted involving intact fragipan soil cores of 50 cm thickness after removing the topsoil horizons. The cores were maintained in moist condition throughout the experiment and received several treatments with various amendments for different periods ranging from 9 to 17 months. The amendments included annual ryegrass or Festulolium residues, powder limestone and various humate compounds alone or in combination with the grass residues. The results suggested a significant effect of ryegrass and Festulolium in reducing penetration resistance into the top 10 cm of the fragipan within 9 - 17 months, particularly when used in combination with certain humate materials such as Leonardite. Apparently, this is the result of the release of certain soluble organic compounds from the plant residues or the humate amendments that increase the solubility of Si and Al associated with the fragipan brittleness, thus decreasing the density of the compacted fragipan material.

关键词： Fragipan Fragipan Horizon Fragipan Soils Changing the Fragipan Annual Ryegrass Changes Fragipan Festulolium Changes Fragipan Amendments That Change the Fragipan

Arabidopsis Mutants and the Network of M icrotu bu le-Associated Functions

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Molecular Plant 2008年第6期1卷 888-898页

作者： Henrik Buschmann Clive w. lloyd Department of Cell and Developmental Biology John Innes Centre 1 Colney Lane Norwich NR4 7UH UK

In early eukaryotes, the microtubule system was engaged in mitosis, intracellular transport, and flagellumbased motility. In the plant lineage, the evolution of a multicellular body involved the conservation of some core functions, the loss of others, and the elaboration of new microtubule functions associated with the multicellular plant habit. This diversification is reflected by the presence of both conserved （animal/fungi-like） and novel （plant-like） sequences encoding microtubule-related functions in the Arabidopsis genome. The collection of microtubule mutants has grown rapidly over recent years. These mutants present a wide range of phenotypes, consistent with the hypothesis of a functional diversification of the microtubule system. In this review, we focus on mutant analysis and, in particular, discuss double mutant analysis as a valuable tool for pinpointing pathways of gene function. A future challenge will be to define the complete network of genetic and physical interactions of microtubule function in plants. In addition to reviewing recent progress in the functional analysis of the ＇MAPome＇, we present an online database of Arabidopsis mutants impaired in microtubule functions.

关键词： cell division cell morphogenesis cytoskeleton genetics development Arabidopsis.

坦桑尼亚梅拉尼坦桑石矿床地质特征及成因模式

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世界地质 2024年第3期43卷 353-362页

作者：孙国锋张明云闫红圃张猛张伟杰 lloyd Shawarira 河南省地质研究院郑州450001 河南省第二地质勘查院有限公司郑州450046 中金国检珠宝玉石质量检验中心有限公司广东深圳518020 津巴布韦地质调查局津巴布韦哈拉雷ZW192201

通过野外实地矿区地质填图,对坦桑尼亚梅拉尼坦桑石矿床的地质背景及矿区矿床地质特征进行详细描述,尤其对矿体及矿物宝石学特征进行了剖析和综述,探讨了宝石成因模式。认为坦桑石形成于约5亿年前的泛非运动,仅产于新元古代莫桑比克变... 详细信息

通过野外实地矿区地质填图,对坦桑尼亚梅拉尼坦桑石矿床的地质背景及矿区矿床地质特征进行详细描述,尤其对矿体及矿物宝石学特征进行了剖析和综述,探讨了宝石成因模式。认为坦桑石形成于约5亿年前的泛非运动,仅产于新元古代莫桑比克变质带的蚀变石墨片麻岩中,属于接触交代成因的矽卡岩矿床,主要受地层岩性和构造变形两个因素控制。

关键词：矽卡岩地质特征坦桑石成因模式梅拉尼

CFD-DEM simulation of Small-Scale Challenge Problem 1 with EMMS bubble-based structure-dependent drag coefficient

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Particuology 2021年第2期19卷 48-61页

作者： Musango Lungu John Siame lloyd Mukosha Multiphase Flow Research Group Chemical Engineering DepartmentSchool of Mines and Mineral SciencesCopperbelt UniversityKitwe 10101Zambia

In this study,the energy minimization multi-scale(EMMS)/Bubbling model is coupled with the computational fluid dynamics/discrete element method(CFD-DEM)model via a structure-dependent drag coefficient to simulate the National Energy Technology Laboratory(NETL)small-scale challenge problem using the open-source multiphase flow code *** numerical predictions are compared against particle velocity measurements obtained from high-speed particle image velocimetry(HSPIV)and differential pressure *** drag-reduction effect of the EMMS bubble-based drag coefficient is observed to significantly improve predictions of the horizontal particle velocity and granular temperature when compared to several other drag coefficients tested;however,the vertical particle velocity and pressure fluctuation characteristic predictions are *** drag-reduction effect is characterized by a reduction in the sizes of slugs or voids,as identified through spectral decomposition of the pressure ***,this study shows great promise in employing drag coefficients,developed via multi-scale approaches(such as the EMMS paradigm),in CFD-DEM models.

关键词： CFD-DEM Drag model EMMS/Bubbling model Fluidization Multi-scale