scholarly journals More Than a Functional Group: Diversity within the Legume–Rhizobia Mutualism and Its Relationship with Ecosystem Function

Diversity ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 50 ◽  
Author(s):  
Benton N. Taylor ◽  
Ellen L. Simms ◽  
Kimberly J. Komatsu
Keyword(s):  
Ecosystem Function ◽  
Functional Group ◽  
Reciprocal Relationship ◽  
Ecosystem Functions ◽  
Negative Effects ◽  
Full Diversity ◽  
Competitive Interference ◽  
Biodiversity And Ecosystem Function ◽  
Dilution Effects ◽  
Group Diversity

Studies of biodiversity and ecosystem function (BEF) have long focused on the role of nitrogen (N)-fixing legumes as a functional group that occupies a distinct and important niche relative to other plants. Because of their relationship with N-fixing rhizobial bacteria, these legumes access a different pool of N than other plants and therefore directly contribute to increases in productivity and N-cycling. Despite their recognized importance in the BEF literature, the field has not moved far beyond investigating the presence/absence of the legume functional group in species mixtures. Here, we synthesize existing information on how the diversity (species richness and functional diversity) of both legumes and the rhizobia that they host impact ecosystem functions, such as nitrogen fixation and primary productivity. We also discuss the often-overlooked reciprocal direction of the BEF relationship, whereby ecosystem function can influence legume and rhizobial diversity. We focus on BEF mechanisms of selection, complementarity, facilitation, competitive interference, and dilution effects to explain how diversity in the legume–rhizobia mutualism can have either positive or negative effects on ecosystem function—mechanisms that can operate at scales from rhizobial communities affecting individual legume functions to legume communities affecting landscape-scale ecosystem functions. To fully understand the relationship between biodiversity and ecosystem function, we must incorporate the full diversity of this mutualism and its reciprocal relationship with ecosystem function into our evolving BEF framework.

scholarly journals Blind spots in global soil biodiversity and ecosystem function research

2019 ◽  
Author(s):  
Carlos A. Guerra ◽  
Anna Heintz-Buschart ◽  
Johannes Sikorski ◽  
Antonis Chatzinotas ◽  
Nathaly Guerrero-Ramírez ◽  
...  
Keyword(s):  
Ecosystem Function ◽  
Ecosystem Functioning ◽  
Ecosystem Functions ◽  
Soil Organisms ◽  
Substantial Fraction ◽  
Soil Biodiversity ◽  
Global Soil ◽  
Biodiversity And Ecosystem Function ◽  
And Function ◽  
Blind Spots

AbstractSoils harbor a substantial fraction of the world’s biodiversity, contributing to many crucial ecosystem functions. It is thus essential to identify general macroecological patterns related to the distribution and functioning of soil organisms to support their conservation and governance. Here we identify and characterize the existing gaps in soil biodiversity and ecosystem function data across soil macroecological studies and >11,000 sampling sites. These include significant spatial, environmental, taxonomic, and functional gaps, and an almost complete absence of temporally explicit data. We also identify the limitations of soil macroecological studies to explore general patterns in soil biodiversity-ecosystem functioning relationships, with only 0.6% of all sampling sites having a non-systematic coverage of both biodiversity and function datasets. Based on this information, we provide clear priorities to support and expand soil macroecological research.

Dominance determines fish community biomass in a temperate seagrass ecosystem

2019 ◽  
Author(s):  
Aaron Matthius Eger ◽  
Rebecca J. Best ◽  
Julia Kathleen Baum
Keyword(s):  
Species Richness ◽  
Ecosystem Function ◽  
Fish Community ◽  
Prey Capture ◽  
Fish Communities ◽  
Functional Trait ◽  
Ecosystem Functions ◽  
Community Biomass ◽  
Ecosystem Valuation ◽  
Species Abundances

Biodiversity and ecosystem function are often correlated, but there are multiple hypotheses about the mechanisms underlying this relationship. Ecosystem functions such as primary or secondary production may be maximized by species richness, evenness in species abundances, or the presence or dominance of species with certain traits. Here, we combined surveys of natural fish communities (conducted in July and August, 2016) with morphological trait data to examine relationships between diversity and ecosystem function (quantified as fish community biomass) across 14 subtidal eelgrass meadows in the Northeast Pacific (54° N 130° W). We employed both taxonomic and functional trait measures of diversity to investigate if ecosystem function is driven by species diversity (complementarity hypothesis) or by the presence or dominance of species with particular trait values (selection or dominance hypotheses). After controlling for environmental variation, we found that fish community biomass is maximized when taxonomic richness and functional evenness is low, and in communities dominated by species with particular trait values – those associated with benthic habitats and prey capture. While previous work on fish communities has found that species richness is positively correlated with ecosystem function, our results instead highlight the capacity for regionally prevalent and locally dominant species to drive ecosystem function in moderately diverse communities. We discuss these alternate links between community composition and ecosystem function and consider their divergent implications for ecosystem valuation and conservation prioritization.

scholarly journals Environmental and Social Risks to Biodiversity and Ecosystem Health—A Bottom-Up, Resource-Focused Assessment Framework

Earth ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 440-456
Author(s):  
Roger A. Pielke ◽  
Jimmy Adegoke ◽  
Faisal Hossain ◽  
Dev Niyogi
Keyword(s):  
Ecosystem Function ◽  
Ecosystem Health ◽  
Interactive System ◽  
Integrative Approach ◽  
Individual Species ◽  
Assessment Framework ◽  
Top Down ◽  
Bottom Up ◽  
Social Risks ◽  
Biodiversity And Ecosystem Function

Risks from human intervention in the climate system are raising concerns with respect to individual species and ecosystem health and resiliency. A dominant approach uses global climate models to predict changes in climate in the coming decades and then to downscale this information to assess impacts to plant communities, animal habitats, agricultural and urban ecosystems, and other parts of the Earth’s life system. To achieve robust assessments of the threats to these systems in this top-down, outcome vulnerability approach, however, requires skillful prediction, and representation of changes in regional and local climate processes, which has not yet been satisfactorily achieved. Moreover, threats to biodiversity and ecosystem function, such as from invasive species, are in general, not adequately included in the assessments. We discuss a complementary assessment framework that builds on a bottom-up vulnerability concept that requires the determination of the major human and natural forcings on the environment including extreme events, and the interactions between these forcings. After these forcings and interactions are identified, then the relative risks of each issue can be compared with other risks or forcings in order to adopt optimal mitigation/adaptation strategies. This framework is a more inclusive way of assessing risks, including climate variability and longer-term natural and anthropogenic-driven change, than the outcome vulnerability approach which is mainly based on multi-decadal global and regional climate model predictions. We therefore conclude that the top-down approach alone is outmoded as it is inadequate for robustly assessing risks to biodiversity and ecosystem function. In contrast the bottom-up, integrative approach is feasible and much more in line with the needs of the assessment and conservation community. A key message of our paper is to emphasize the need to consider coupled feedbacks since the Earth is a dynamically interactive system. This should be done not just in the model structure, but also in its application and subsequent analyses. We recognize that the community is moving toward that goal and we urge an accelerated pace.

scholarly journals The dynamic association between body mass index and cognition from midlife through late-life, and the effect of sex and genetic influences

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ida K. Karlsson ◽  
Margaret Gatz ◽  
Thalida Em Arpawong ◽  
Anna K. Dahl Aslan ◽  
Chandra A. Reynolds
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Genetic Predisposition ◽  
Cognitive Abilities ◽  
Late Life ◽  
Change Score ◽  
Reciprocal Relationship ◽  
European Ancestry ◽  
Negative Effects ◽  
Dynamic Relationship

AbstractBody mass index (BMI) is associated with cognitive abilities, but the nature of the relationship remains largely unexplored. We aimed to investigate the bidirectional relationship from midlife through late-life, while considering sex differences and genetic predisposition to higher BMI. We used data from 23,892 individuals of European ancestry from the Health and Retirement Study, with longitudinal data on BMI and three established cognitive indices: mental status, episodic memory, and their sum, called total cognition. To investigate the dynamic relationship between BMI and cognitive abilities, we applied dual change score models of change from age 50 through 89, with a breakpoint at age 65 or 70. Models were further stratified by sex and genetic predisposition to higher BMI using tertiles of a polygenic score for BMI (PGSBMI). We demonstrated bidirectional effects between BMI and all three cognitive indices, with higher BMI contributing to steeper decline in cognitive abilities in both midlife and late-life, and higher cognitive abilities contributing to less decline in BMI in late-life. The effects of BMI on change in cognitive abilities were more evident in men compared to women, and among those in the lowest tertile of the PGSBMI compared to those in the highest tertile, while the effects of cognition on BMI were similar across groups. In conclusion, these findings highlight a reciprocal relationship between BMI and cognitive abilities, indicating that the negative effects of a higher BMI persist from midlife through late-life, and that weight-loss in late-life may be driven by cognitive decline.

scholarly journals COVID-19 Pandemic Turns Life-Science Students into “Citizen Scientists”: Data Indicate Multiple Negative Effects of Urbanization on Biota

2021 ◽  
Vol 13 (5) ◽  
pp. 2992
Author(s):  
Jens Schirmel
Keyword(s):  
Citizen Science ◽  
Online Teaching ◽  
Teaching Strategy ◽  
Ecosystem Functions ◽  
Negative Effects ◽  
Ecological Data ◽  
Pollinating Insects ◽  
Impact Of Urbanization ◽  
Data Collections ◽  
The Impact

The COVID-19 pandemic and its restrictions strongly affect the higher education community and require diverse teaching strategies. We designed a course where we combined online teaching with independently conducted ecological data collections by students using a “citizen science” approach. The aim was to analyze the impact of urbanization on biota by comparing urban and rural grasslands. Seventy-five students successfully conducted the data collections and the results provide evidence for prevailing negative effects of urbanization. Individual numbers of ground-dwelling invertebrates (−25%) and pollinating insects (−33%) were generally lower in urban sites. Moreover, animal and seed predation were reduced in urban grasslands, indicating the potential of urbanization to alter ecosystem functions. Despite the general limitations of online teaching and citizen science approaches, outcomes of this course showed this combination can be a useful teaching strategy, which is why this approach could be used to more actively involve students in scientific research.

Linking functional group richness and ecosystem functions of dung beetles: an experimental quantification

Oecologia ◽  
2016 ◽  
Vol 183 (1) ◽  
pp. 177-190 ◽  
Author(s):  
Tanja Milotić ◽  
Stijn Quidé ◽  
Thomas Van Loo ◽  
Maurice Hoffmann
Keyword(s):  
Functional Group ◽  
Dung Beetles ◽  
Ecosystem Functions

scholarly journals The effects of earthworm functional group diversity on earthworm community structure

Pedobiologia ◽  
2007 ◽  
Vol 50 (6) ◽  
pp. 479-487 ◽  
Author(s):  
Cróna Sheehan ◽  
Laura Kirwan ◽  
John Connolly ◽  
Thomas Bolger
Keyword(s):  
Community Structure ◽  
Functional Group ◽  
Group Diversity

scholarly journals Different processes shape prokaryotic and picoeukaryotic assemblages in the sunlit ocean microbiome

2018 ◽  
Author(s):  
Ramiro Logares ◽  
Ina M. Deutschmann ◽  
Caterina. R. Giner ◽  
Anders K. Krabberød ◽  
Thomas S. B. Schmidt ◽  
...  
Keyword(s):  
Ecosystem Function ◽  
Sequence Data ◽  
Scale Effects ◽  
Dispersal Limitation ◽  
Global Scale ◽  
Global Ocean ◽  
Ecosystem Functions ◽  
Ecological Processes ◽  
Surface Ocean

ABSTRACTThe smallest members of the sunlit-ocean microbiome (prokaryotes and picoeukaryotes) participate in a plethora of ecosystem functions with planetary-scale effects. Understanding the processes determining the spatial turnover of this assemblage can help us better comprehend the links between microbiome species composition and ecosystem function. Ecological theory predicts thatselection,dispersalanddriftare main drivers of species distributions, yet, the relative quantitative importance of these ecological processes in structuring the surface-ocean microbiome is barely known. Here we quantified the role of selection, dispersal and drift in structuring surface-ocean prokaryotic and picoeukaryotic assemblages by using community DNA-sequence data collected during the global Malaspina expedition. We found that dispersal limitation was the dominant process structuring picoeukaryotic communities, while a balanced combination of dispersal limitation, selection and drift shaped prokaryotic counterparts. Subsequently, we determined the agents exerting abiotic selection as well as the spatial patterns emerging from the action of different ecological processes. We found that selection exerted via temperature had a strong influence on the structure of prokaryotic communities, particularly on species co-occurrences, a pattern not observed among communities of picoeukaryotes. Other measured abiotic variables had limited selective effects on microbiome structure. Picoeukaryotes presented a higher differentiation between neighbouring communities and a higher distance-decay when compared to prokaryotes, agreeing with their higher dispersal limitation. Finally, drift seemed to have a limited role in structuring the sunlit-ocean microbiome. The different predominance of ecological processes acting on particular subsets of the ocean microbiome suggests uneven responses to environmental change.SIGNIFICANCE STATEMENTThe global ocean contains one of the largest microbiomes on Earth and changes on its structure can impact the functioning of the biosphere. Yet, we are far from understanding the mechanisms that structure the global ocean microbiome, that is, the relative importance of environmentalselection,dispersaland random events (drift). We evaluated the role of these processes at the global scale, based on data derived from a circumglobal expedition and found that these ecological processes act differently on prokaryotes and picoeukaryotes, two of the main components of the ocean microbiome. Our work represents a significant contribution to understand the assembly of marine microbial communities, providing also insights on the links between ecological mechanisms, microbiome structure and ecosystem function.

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