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| 1 | An Exploratory Study of Employee Silence: Issues that Employees Don’t Communicate Upward and Why*显示文摘 | Frances J.Milliken Elizabeth W.Morrison Patricia F.Hewlin | 2003 | Journal of Management Studies2003，，6： | 2 |
| 2 | Nestedness in insular floras:spatiotemporal variation and underlying mechanisms显示文摘Aims Nestedness is a characteristic of insular metacommunity structure.Relatively few studies,however,have attempted to evaluate temporal changes in nestedness,or elucidate the mechanisms underlying nestedness.I evaluated both spatial and temporal patterns of nestedness in the insular floras of four archipelagoes of small islands in the Bahamas and the potential underlying environmental gradients.Methods The NODF(a nestedness metric based on overlap and decreasing fill)and the matrix temperature measure,T,were used to quantify nestedness in insular floras on small islands near Abaco,Andros,Great Exuma and the Exuma Cays,Bahamas.Two different null models were employed for each nestedness measure.Six environmental variables were evaluated in relation to nestedness by ordering islands according to gradients and recalculating NODF scores.Important Findings All archipelagoes were significantly nested.Nestedness among sites contributed more to overall nestedness than did nestedness among species.NODF scores varied among archipelagoes,but were surprisingly constant over time.Ordering islands by vegetated area yielded the highest nestedness scores for three archipelagoes;ordering islands by protection from exposure yielded the highest nestedness score for one archipelago.Nestedness scores varied little over time even though species compositions changed,indicating that extinctions occurred in a deterministic manner.The relative importance of area suggests extinction is an important mechanism in producing nestedness.Attempting to determine the relative importance of immigrations or extinctions requires some assumptions,however,and both processes are likely cumulative in most cases. | Lloyd W.Morrison | 2013 | Journal of Plant Ecology2013，6，6： | 2 |
| 3 | Observer error in vegetation surveys:a review显示文摘Aims Vegetation sampling employing observers is prone to both inter-observer and intra-observer error.Three types of errors are common:(i)overlooking error(i.e.not observing species actually present),(ii)misidentification error(i.e.not correctly identifying species)and(iii)estimation error(i.e.not accurately estimating abundance).I conducted a literature review of 59 articles that provided quantitative estimates or statistical inferences regarding observer error in vegetation studies.Important FindingsAlmost all studies(92%)that tested for a statistically significant effect of observer error found at least one significant comparison.In 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 error.Sources of error commonly include both characteristics of the vegetation(e.g.small size of populations,rarity,morphology,phenology)and attributes of the observers(e.g.mental 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. | Lloyd W.Morrison | 2016 | Journal of Plant Ecology2016，9，4： | 1 |
| 4 | An Exploratory Study of Employee Silence: Issues that Employees Don’t Communicate Upward and Why*显示文摘 | Frances J.Milliken Elizabeth W.Morrison Patricia F.Hewlin | 2003 | Journal of Management Studies2003，，6： | 1 |
| 5 | Interobserver error in grassland vegetation surveys:sources and implications显示文摘人类观测误差是植被测量中不可避免的一个问题。我们量化了与高草草原植被长期监测相关的观测者间误差的四个组成部分:忽略误差、误识别误差、谨慎误差和估计误差。由于观察者会产生误差,我们还评估了地块大小与伪周转率的关系,以及对比了物种组成和丰度的伪变化与四年间植被变化之间的关系。这项研究是在美国堪萨斯州的高草草原国家保护区进行的。监测点包括10个地块,每个地块由一系列的四个嵌套框架(0.01,0.1,1和10 m^(2))组成。在每个嵌套框架中记录了所有的草本物种,并且在10 m^(2)的空间尺度下,视觉估计了7个覆盖类别内的叶面覆盖。总共调查了300个地块(30个地点),并随机选择28个地块重新进行测量以评估观测者的误差。所有的调查由四名观测者分两组完成。研究结果表明,在10 m^(2)空间尺度上,由忽略误差引起的伪周转率平均为18.6%,而由误识别误差和谨慎误差引起的伪周转率平均值分别为1.4%和0.6%。尽管由重新定位引起的误差可能也起一定的作用,由忽略误差导致的伪周转率随样地面积的减小而增加。物种组成在四年期间的变化(排除潜在的误识别误差和谨慎误差)为30.7%,其中包括由忽略误差和实际变化引起的伪周转率。18.6%的忽略误差表明四年期间的实际变化只有12.1%。对于估计误差,26.2%会记录为不同的覆盖等级。在四年的时间内,46.9%的记录显示了不同的覆盖等级,这表明两个时间段间覆盖率变化的56%是由于观测者误差造成的。 | Lloyd W.Morrison Sherry A.Leis Michael D.DeBacker | 2020 | Journal of Plant Ecology2020，13，5： | 0 |
| 6 | 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显示文摘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。 | Lloyd W.Morrison Sherry A.Leis Michael D.DeBacker | 2023 | Journal of Plant Ecology2023，16，4： | 0 |
| 7 | 全球红火蚁扩张范围预测显示文摘 | Lloyd W.Morrison 郑剑宁 宋晔晔 裘炯良 薛新春 | 2006 | 中华卫生杀虫药械2006，12，1： | 0 |
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