Bio-Ecological Diversity vs. Socio-Economic Diversity: A Comparison of Existing Measures

This paper aims to enrich the standard toolbox for measuring diversity in economics. In so doing, we compare the indicators of diversity used by economists with those used by biologists and ecologists. Ecologists and biologists are concerned about biodiversity: the diversity of organisms that inhabit a given area. Concepts of species diversity such as alpha (diversity within community), beta (diversity across communities) and gamma (diversity due to differences among samples when they are combined into a single sample) have been developed (Whittaker, 1960). Biodiversity is more complex than just the species that are present, it includes species richness and species evenness. Those various aspects of diversity are measured by biodiversity indices such as Simpson’s Diversity Indices, Species Richness Index, Shannon Weaver Diversity Indices, Patil and Taillie Index, Modified Hill’s Ratio. In economics, diversity measures are multi-faceted ranging from inequality (Lorenz curve, Gini coefficient, quintile distribution), to polarisation (Esteban and Ray, 1994; Wolfon, 1994, D’Ambrosio (2001)) and heterogeneity (Alesina, Baqir and Hoxby, 2000). We propose an interdisciplinary comparison between indicators. We review their theoretical background and applications. We provide an assessment of their possible use according to their specific properties.Diversity, Growth, Knowledge

Bio-Ecological Diversity vs. Socio-Economic Diversity: A Comparison of Existing Measures

This paper aims to enrich the standard toolbox for measuring diversity in economics. In so doing, we compare the indicators of diversity used by economists with those used by biologists and ecologists. Ecologists and biologists are concerned about biodiversity: the diversity of organisms that inhabit a given area. Concepts of species diversity such as alpha (diversity within community), beta (diversity across communities) and gamma (diversity due to differences among samples when they are combined into a single sample) have been developed (Whittaker, 1960). Biodiversity is more complex than just the species that are present, it includes species richness and species evenness. Those various aspects of diversity are measured by biodiversity indices such as Simpson’s Diversity Indices, Species Richness Index, Shannon Weaver Diversity Indices, Patil and Taillie Index, Modified Hill’s Ratio. In economics, diversity measures are multi-faceted ranging from inequality (Lorenz curve, Gini coefficient, quintile distribution), to polarisation (Esteban and Ray, 1994; Wolfon, 1994, D’Ambrosio (2001)) and heterogeneity (Alesina, Baqir and Hoxby, 2000). We propose an interdisciplinary comparison between indicators. We review their theoretical background and applications. We provide an assessment of their possible use according to their specific properties.This paper aims to enrich the standard toolbox for measuring diversity in economics. In so doing, we compare the indicators of diversity used by economists with those used by biologists and ecologists. Ecologists and biologists are concerned about biodiversity: the diversity of organisms that inhabit a given area. Concepts of species diversity such as alpha (diversity within community), beta (diversity across communities) and gamma (diversity due to differences among samples when they are combined into a single sample) have been developed (Whittaker, 1960). Biodiversity is more complex than just the species that are present, it includes species richness and species evenness. Those various aspects of diversity are measured by biodiversity indices such as Simpson’s Diversity Indices, Species Richness Index, Shannon Weaver Diversity Indices, Patil and Taillie Index, Modified Hill’s Ratio. In economics, diversity measures are multi-faceted ranging from inequality (Lorenz curve, Gini coefficient, quintile distribution), to polarisation (Esteban and Ray, 1994; Wolfon, 1994, D’Ambrosio (2001)) and heterogeneity (Alesina, Baqir and Hoxby, 2000). We propose an interdisciplinary comparison between indicators. We review their theoretical background and applications. We provide an assessment of their possible use according to their specific properties.Non-Refereed Working Papers / of national relevance onl

Soil Microbial Networks Shift Across a High-Elevation Successional Gradient.

While it is well established that microbial composition and diversity shift along environmental gradients, how interactions among microbes change is poorly understood. Here, we tested how community structure and species interactions among diverse groups of soil microbes (bacteria, fungi, non-fungal eukaryotes) change across a fundamental ecological gradient, succession. Our study system is a high-elevation alpine ecosystem that exhibits variability in successional stage due to topography and harsh environmental conditions. We used hierarchical Bayesian joint distribution modeling to remove the influence of environmental covariates on species distributions and generated interaction networks using the residual species-to-species variance-covariance matrix. We hypothesized that as ecological succession proceeds, diversity will increase, species composition will change, and soil microbial networks will become more complex. As expected, we found that diversity of most taxonomic groups increased over succession, and species composition changed considerably. Interestingly, and contrary to our hypothesis, interaction networks became less complex over succession (fewer interactions per taxon). Interactions between photosynthetic microbes and any other organism became less frequent over the gradient, whereas interactions between plants or soil microfauna and any other organism were more abundant in late succession. Results demonstrate that patterns in diversity and composition do not necessarily relate to patterns in network complexity and suggest that network analyses provide new insight into the ecology of highly diverse, microscopic communities

Avian taxonomic and functional diversity in early stage of longleaf pine (Pinus palustris) stands restored at agricultural lands: Variations in scale dependency

In agricultural landscapes, the Longleaf Pine Initiative (LLPI) and the Bobwhite Quail Initiative (BQI) aim to restore longleaf pine forests and early successional habitats, respectively. The early stage of longleaf pine stands and grass and forb vegetation produced by a combination of both restoration programs (LLPI-BQI) may form habitat conditions favorable to early successional bird species and other birds, increasing avian diversity. We investigated how the LLPI and BQI programs affected taxonomic and functional diversity of birds and abundance of early successional birds (grassland and scrub/shrub species), and what environmental characteristics were associated with the diversity and abundance of birds. Our study was performed at 41 fields in Georgia, USA, during 2001-2002 by considering environmental characteristics at two spatial scales: local-scale vegetation features and restoration program type (LLPI or LLPI-BQI) and landscape-scale vegetation features and landscape heterogeneity. Functional evenness, species richness, and abundance of grassland and scrub/shrub species did not show a clear association with local- or landscape-scale variables. Shannon-Wiener diversity was slightly influenced by restoration program type (local-scale variable) with higher value at LLPI-BQI stands than at LLPI stands despite no significant differences in local vegetation features between those stands. Functional divergence was strongly positively associated with landscape-scale variables. That is, niche differentiation increased with increasing shrub coverage within a landscape, reducing competition between abundant bird species and others. Our results suggest that although a combination of BQI and LLPI program may have a positive effect on avian taxonomic diversity, it is important to consider shrub vegetation cover within a landscape to improve functional diversity

Avian taxonomic and functional diversity in early stage of longleaf pine (Pinus palustris) stands restored at agricultural lands: Variations in scale dependency

In agricultural landscapes, the Longleaf Pine Initiative (LLPI) and the Bobwhite Quail Initiative (BQI) aim to restore longleaf pine forests and early successional habitats, respectively. The early stage of longleaf pine stands and grass and forb vegetation produced by a combination of both restoration programs (LLPI-BQI) may form habitat conditions favorable to early successional bird species and other birds, increasing avian diversity. We investigated how the LLPI and BQI programs affected taxonomic and functional diversity of birds and abundance of early successional birds (grassland and scrub/shrub species), and what environmental characteristics were associated with the diversity and abundance of birds. Our study was performed at 41 fields in Georgia, USA, during 2001-2002 by considering environmental characteristics at two spatial scales: local-scale vegetation features and restoration program type (LLPI or LLPI-BQI) and landscape-scale vegetation features and landscape heterogeneity. Functional evenness, species richness, and abundance of grassland and scrub/shrub species did not show a clear association with local- or landscape-scale variables. Shannon-Wiener diversity was slightly influenced by restoration program type (local-scale variable) with higher value at LLPI-BQI stands than at LLPI stands despite no significant differences in local vegetation features between those stands. Functional divergence was strongly positively associated with landscape-scale variables. That is, niche differentiation increased with increasing shrub coverage within a landscape, reducing competition between abundant bird species and others. Our results suggest that although a combination of BQI and LLPI program may have a positive effect on avian taxonomic diversity, it is important to consider shrub vegetation cover within a landscape to improve functional diversity

Microhabitats Shape Bacterial Community Composition, Ecosystem Function, and Genome Traits

This dissertation helps to integrate bacteria into the broader field of ecology by investigating bacterial community composition and diversity as it relates to ecosystem function in microhabitats within freshwater systems of the Great Lakes Region. Here, I combine field- and laboratory-based measurements of observational data collected from three major types of lake ecosystems: inland lakes, a freshwater estuary (Muskegon Lake), and a Great Lake (Lake Michigan). First, to determine the primary controls on lake bacterial community composition, I assessed the influence of lake layer (i.e. stratification), lake productivity, and particle-association on the bacterial community across 11 inland lakes with varying productivity in Southwestern Michigan. I found that particle-association very strongly structures freshwater bacterial community composition. Second, I studied a freshwater estuarine lake, Muskegon Lake, which has a large spatio-temporal variation in bacterial heterotrophic productivity, to test whether there was an association between heterotrophic production and bacterial biodiversity (defined as the number of taxa and taxon abundance). I specifically focused on two co-occurring freshwater habitats that my first chapter showed to be populated by very distinct communities: particle-associated and free-living. Positive biodiversity-heterotrophic productivity relationships were found only in particles. Third, I performed a genome-based analysis of free-living specialists, particle-associated bacterial specialists, and generalists to characterize the genomic architecture and genetic traits that are associated with adaptations to these specific habitats. The genomes of particle-associated specialist bacteria were about twice the size of the genomes of free-living specialists and generalists, which had streamlined genomes. Fourth, to identify the bacterial taxa driving heterotrophic productivity across the large set of lake samples, I found that high nucleic acid (i.e., HNA) functional groups identified by flow cytometry can serve as a proxy for freshwater bacterial heterotrophic productivity, whereas low nucleic acid (i.e., LNA) functional groups cannot. Then, I used a machine learning approach to identify bacterial taxa associated with HNA and LNA. This allowed me to identify the bacterial taxa, which were often members of the Phylum Bacteroidetes, that are associated heterotrophic productivity. Finally, I investigated patterns of lake specificity and phylogenetic conservation of taxonomic groups. Throughout my dissertation, I found that there was very deep (Class to Phylum-level) phylogenetic conservation of which bacteria lived in which habitats, but not of what bacterial taxa contributed to HNA and LNA functional groups, and thus heterotrophic productivity. Positive biodiversity-heterotrophic productivity relationships only existed in particle-associated, and not free-living communities, and communities composed of more phylogenetically related organisms were more productive per-capita. These differences in biodiversity-ecosystem function relationships may in part be explained by particle-associated bacteria having larger genomes, higher nitrogen content, and more unique genes that provide the potential for niche complementarity. The taxa that drove HNA and LNA cell numbers, and by proxy heterotrophic productivity, were lake and time-specific and indicated that taxa could switch between the two functional groups. Overall, my dissertation elucidates the ecological and evolutionary effects of microhabitat structure on bacterial communities and genomes in natural systems.PHDEcology and Evolutionary BiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/147651/1/marschmi_1.pd

Redefining the field to mobilize three-dimensional diversity and ecosystem services on the arable farm

In this article we explore the concept and implications of three-dimensional (spatial, temporal, and genetic) infield crop diversification to inform systems redesign towards ecological intensification. We first present a conceptual framework for classifying diversity in arable contexts. We then apply the framework to analyse two longterm systems experiments in The Netherlands where spatial and genetic diversity measures were implemented via strip and mixed intercropping with the aim to increase ecosystem service delivery: incidence and spreading rate of late blight (Phytophthora infestans) in potato (Solanum tubersosum L.), and biocontrol control potential in wheat (Triticum aestivum L.). In the case of late blight, potatoes planted in strips had significantly lower disease incidence than the monoculture reference across all years, and adding cultivar mixing within the strip was more powerful in mitigating late blight than spatial diversification alone. In the case of biocontrol in wheat, strips supported significantly larger (for all but one taxonomic group) and significantly more diverse epigeic natural enemy populations than the sole culture reference in all years. However, the addition of species mixing within strips did not further increase biocontrol indices compared to sole-wheat strips. These results imply that compromises between management complexity and ecosystem service enhancement are achievable through strip cropping, an operable practice with current machinery, and one that does not require a thorough reconfiguration of the production system. The three-dimensional diversity framework proved useful for unpacking experimental outcomes in terms of diversity-mediated mechanisms, however it requires further development before it can be used to facilitate multi-objective optimization

Evaluation of estuarine biotic indices to assess macro-benthic structure and functioning following nutrient remediation actions: A case study on the Eden estuary Scotland

© 2018 Despite a wealth of methods currently proposed by the European Water Framework Directive (WFD) to assess macro-benthic integrity, determining good ecological status (GES) and assessing ecosystem recovery following anthropogenic degradation is still one of the biggest challenges in marine ecology research. In this study, our aim was to test a number of commonly used structural (e.g. Shannon–Wiener, Average Taxonomic Diversity ([Formula presented]), M-AMBI) and functional indicators (e.g. BTA, BPc) currently used in benthic research and monitoring programmes on the Eden estuary (Scotland). Historically the estuary has a legacy of high nutrient conditions and was designated as a Nitrate Vulnerable Zone (NVZ) in 2003, whence major management measures were implemented in order to ameliorate the risk of eutrophication symptoms. We therefore collected data on intertidal macro-benthic communities over a sixteen year interval, covering a pre-management (1999) and post-management (2015) period to assess the effectiveness of the intended restoration efforts. In the post-management period, the results suggested an improvement in the structure and functioning of the estuary as a whole, but macro-benthic assemblages responded to restoration variably along the estuarine gradient. The greatest improvements were noticed in the upper and central sites of the estuary with functional traits analysis suggesting an increased ability of these sites to provide ecosystem services associated with the benthic environment such as carbon and organic matter cycling. Generally, almost all of the structural and functional indicators detected the prevailing environmental conditions (with the exception of (Pielou's index and Average Taxonomic Diversity ([Formula presented])), highlighting the appropriateness of such methods to be used in monitoring the recovery of transitional systems. This research also provides a robust baseline to monitor further management actions in the Eden estuary and provides evidence that notable reductions in nitrate concentrations resulting from NVZ designations may result in significant improvements to benthic structure and functioning