Cox Kieran D, Black Morgan J, Filip Natalia, Miller Matthew R, Mohns Kayla, Mortimor James, Freitas Thaise R, Greiter Loerzer Raquel, Gerwing Travis G, Juanes Francis, Dudas Sarah E
Hakai Institute Calvert Island BC Canada.
Department of Biology University of Victoria Victoria BC Canada.
Ecol Evol. 2017 Nov 21;7(24):11213-11226. doi: 10.1002/ece3.3580. eCollection 2017 Dec.
Diversity estimates play a key role in ecological assessments. Species richness and abundance are commonly used to generate complex diversity indices that are dependent on the quality of these estimates. As such, there is a long-standing interest in the development of monitoring techniques, their ability to adequately assess species diversity, and the implications for generated indices. To determine the ability of substratum community assessment methods to capture species diversity, we evaluated four methods: photo quadrat, point intercept, random subsampling, and full quadrat assessments. Species density, abundance, richness, Shannon diversity, and Simpson diversity were then calculated for each method. We then conducted a method validation at a subset of locations to serve as an indication for how well each method captured the totality of the diversity present. Density, richness, Shannon diversity, and Simpson diversity estimates varied between methods, despite assessments occurring at the same locations, with photo quadrats detecting the lowest estimates and full quadrat assessments the highest. Abundance estimates were consistent among methods. Sample-based rarefaction and extrapolation curves indicated that differences between Hill numbers (richness, Shannon diversity, and Simpson diversity) were significant in the majority of cases, and coverage-based rarefaction and extrapolation curves confirmed that these dissimilarities were due to differences between the methods, not the sample completeness. Method validation highlighted the inability of the tested methods to capture the totality of the diversity present, while further supporting the notion of extrapolating abundances. Our results highlight the need for consistency across research methods, the advantages of utilizing multiple diversity indices, and potential concerns and considerations when comparing data from multiple sources.
多样性估计在生态评估中起着关键作用。物种丰富度和多度通常用于生成依赖于这些估计质量的复杂多样性指数。因此，人们长期以来一直关注监测技术的发展、它们充分评估物种多样性的能力以及对生成指数的影响。为了确定基质群落评估方法捕捉物种多样性的能力，我们评估了四种方法：照片样方、点截距、随机子抽样和全样方评估。然后计算每种方法的物种密度、多度、丰富度、香农多样性和辛普森多样性。然后我们在一部分地点进行了方法验证，以表明每种方法捕捉到的现有多样性的总体情况如何。尽管在相同地点进行评估，但密度、丰富度、香农多样性和辛普森多样性估计在不同方法之间存在差异，照片样方检测到的估计值最低，全样方评估最高。多度估计在各方法之间是一致的。基于样本的稀疏和外推曲线表明，在大多数情况下，希尔数（丰富度、香农多样性和辛普森多样性）之间的差异是显著的，基于覆盖度的稀疏和外推曲线证实这些差异是由于方法之间的差异，而不是样本完整性。方法验证突出了所测试方法无法捕捉现有多样性的总体情况，同时进一步支持了外推多度的概念。我们的结果强调了研究方法一致性的必要性、使用多个多样性指数的优势以及在比较来自多个来源的数据时潜在的问题和考虑因素。
