The Influence of Beached Harmful Algal Blooms On Terrestrial Arthropods on the Shore of Lake Erie

Marine primary inputs, such as sea wrack and algae, offer a great niche for insects and other animals to exploit. The existence of a similar niche on the coast of lakes has received less attention. To complicate matters, many freshwater systems are seeing increases in proliferation of toxic and non-toxic cyanobacteria blooms. This study examined patterns in lake shore terrestrial arthropod abundance, diversity, and community composition across gradients of beached algae, with varying toxicity. We detected water microcystin effects on arthropod richness in survey three, beached material effects on Shannon’s Diversity in survey two, and water microcystin effects on the community structure on survey three. Our results suggest the beached aquatic inputs have diversifying effect and microcystin has a positive indirect relationship with certain orders of arthropods such as flies and spiders. We recommend further study into the mechanisms surrounding shore arthropod resource utilization and predator release from toxic blooms

Biodiversity Scale-Dependence and Opposing Multi-level Correlations Underlie Differences among Taxonomic, Phylogenetic and Functional Diversity

Aim: Biodiversity is a multidimensional property of biological communities that represents different information depending on how it is measured, but how dimensions relate to one another and under what conditions is not well understood. We explore how taxonomic, phylogenetic, and functional diversity can differ in scale-of-effect dependence and habitat-biodiversity relationships, and subsequently how spatial differences among biodiversity dimensions may arise. Location: Nebraska, United States. Taxon: Birds. Methods: Across 2016 and 2017, we conducted 2,641 point counts at 781 sites. We modeled the occupancy of 141 species using Bayesian Bernoulli-Bernoulli hierarchical logistic regressions. We calculated species richness (SR), phylogenetic diversity (PD), and functional diversity (FD) for each site and year based on predicted occupancy, accounting for imperfect detection. Using Bayesian latent indicator scale selection and multivariate modeling, we quantified the spatial scales-of-effect that best explained the relationships between environmental characteristics and SR, PD, and FD. Additionally, we decomposed the residual between-site and within-site biodiversity correlations using our repeated measures design. Results: Although relationships between specific land cover types and SR, PD, and FD were qualitatively similar, the spatial scales at which these variables were important in explaining biodiversity differed among dimensions. Between-site residual biodiversity correlations were negative, yet within-site biodiversity residual correlations were positive. Main conclusions: Our results demonstrate how spatial differences among biodiversity dimensions may arise from biodiversity-specific scale-dependent habitat relationships, low shared environmental correlations, and opposing residual correlations between dimensions, suggesting that single-scale and single-dimension analyses are not entirely appropriate for quantifying habitat-biodiversity relationships. After accounting for shared habitat relationships, we found positive within-site residual correlations between SR, PD, and FD, suggesting that habitat change over time influenced all biodiversity dimensions similarly. However, negative between-site residual correlation among biodiversity dimensions may indicate trade-offs in achieving maximum biodiversity across multiple biodiversity dimensions at any given location

Relationships Among Biodiversity Dimensions of Birds in Nebraska

Biological diversity, or biodiversity, is a multi-dimensional concept that can be decomposed to measure information about taxonomic, phylogenetic, and functional variation within communities. Although the dimensions of biodiversity are interrelated, the assumption that measuring one dimension of diversity can inform about patterns in another dimension does not necessarily follow from theory or empirical study. The relationships among biodiversity dimensions is not well understood, nor how differences among dimensions could influence conservation decision making. Using the avian community as a study system, we explored the relationships of breadth metrics from the taxonomic, phylogenetic, and functional dimensions among each other and across six gradients of land cover in Nebraska, USA. We found that all three metrics had a high between-sites correlation, yet the within-site correlation was weaker and even slightly negative, which suggests that these metrics could be used as adequate surrogates for one another broadly, yet they would generally be poor predictors locally. We also found substantial differences in spatial scale selection among the diversity metrics, which suggests that these metrics are being influences by different ecological and evolutionary processes. Within each metric’s selected spatial scale, land cover relationships were generally similar, yet projected differences in the relationships across land cover resulted in spatial mismatches, often of substantial magnitude. Differences among diversity metrics may help identify drivers of biodiversity patterns and predict community assembly. Furthermore, the taxonomic metric showed relative insensitivity compared to the phylogenetic and functional metric, suggesting managing for high taxonomic diversity offers a simple and strategic conservation opportunity to preserve phylogenetic and functional diversity as well. Once conservation areas are selected, holistic or intensively managed conservation approaches are recommended. Advisors: Erica F. Stuber and Joseph J. Fontain