scholarly journals Ecosystem responses to exotic earthworm invasion in northern North American forests

2019 ◽  
Vol 5 ◽  
Author(s):  
Nico Eisenhauer ◽  
Olga Ferlian ◽  
Dylan Craven ◽  
Jes Hines ◽  
Malte Jochum
Keyword(s):  
North American ◽  
Ecosystem Functioning ◽  
Soil Fauna ◽  
Ecosystem Processes ◽  
Global Scale ◽  
Ecosystem Responses ◽  
Earthworm Invasion ◽  
Exotic Earthworms ◽  
Meta Analyses ◽  
Gains And Losses

Earth is experiencing a substantial loss of biodiversity at the global scale, while both species gains and losses are occurring at local and regional scales. The influence of these nonrandom changes in species distributions could profoundly affect the functioning of ecosystems and the essential services that they provide. However, few experimental tests have been conducted examining the influence of species invasions on ecosystem functioning. Even fewer have been conducted using invasive ecosystem engineers, which can have disproportionately strong influence on native ecosystems relative to their own biomass. The invasion of exotic earthworms is a prime example of an ecosystem engineer that is influencing many ecosystems around the world. In particular, European earthworm invasions of northern North American forests cause simultaneous species gains and losses with significant consequences for essential ecosystem processes like nutrient cycling and crucial services to humanity like soil erosion control and carbon sequestration. Exotic earthworms are expected to select for specific traits in communities of soil microorganisms (fast-growing bacteria species), soil fauna (promoting the bacterial energy channel), and plants (graminoids) through direct and indirect effects. This will accelerate some ecosystem processes and decelerate others, fundamentally altering how invaded forests function. This project aims to investigate ecosystem responses of northern North American forests to earthworm invasion. Using a novel, synthetic combination of field observations, field experiments, lab experiments, and meta-analyses, the proposed work will be the first systematic examination of earthworm effects on (1) plant communities and (2) soil food webs and processes. Further, (3) effects of a changing climate (warming and reduced summer precipitation) on earthworm performance will be investigated in a unique field experiment designed to predict the future spread and consequences of earthworm invasion in North America. By assessing the soil chemical and physical properties as well as the taxonomic (e.g., by the latest next-generation sequencing techniques) and functional composition of plant, soil microbial and animal communities and the processes they drive in four forests, work packages I-III take complementary approaches to derive a comprehensive and generalizable picture of how ecosystems change in response to earthworm invasion. Finally, in work package IV, meta-analyses will be used to integrate the information from work packages I-III and existing literature to investigate if earthworms cause invasion waves, invasion meltdowns, habitat homogenization, and ecosystem state shifts. Global data will be synthesized to test if the relative magnitude of effects differs from place to place depending on the functional dissimilarity between native soil fauna and exotic earthworms. Moving from local to global scale, the present proposal examines the influence of earthworm invasions on biodiversity–ecosystem functioning relationships from an aboveground–belowground perspective in natural settings. This approach is highly innovative as it utilizes the invasion by exotic earthworms as an exciting model system that links invasion biology with trait-based community ecology, global change research, and ecosystem ecology, pioneering a new generation of biodiversity–ecosystem functioning research.

scholarly journals Earthworm invasion causes declines across soil fauna size classes and biodiversity facets in northern North American forests

Oikos ◽  
2021 ◽  
Author(s):  
Malte Jochum ◽  
Olga Ferlian ◽  
Madhav P. Thakur ◽  
Marcel Ciobanu ◽  
Bernhard Klarner ◽  
...  
Keyword(s):  
North American ◽  
Soil Fauna ◽  
Size Classes ◽  
Earthworm Invasion

scholarly journals Global‐scale characterization of turning points in arid and semi‐arid ecosystem functioning

2020 ◽  
Vol 29 (7) ◽  
pp. 1230-1245 ◽  
Author(s):  
Paulo N. Bernardino ◽  
Wanda De Keersmaecker ◽  
Rasmus Fensholt ◽  
Jan Verbesselt ◽  
Ben Somers ◽  
...  
Keyword(s):  
Ecosystem Functioning ◽  
Turning Points ◽  
Global Scale ◽  
Arid Ecosystem ◽  
Scale Characterization ◽  
Semi Arid

First comparison of quantitative estimates of termite biomass and abundance reveals strong intercontinental differences

2014 ◽  
Vol 30 (2) ◽  
pp. 143-152 ◽  
Author(s):  
Cecilia A.L. Dahlsjö ◽  
Catherine L. Parr ◽  
Yadvinder Malhi ◽  
Homathevi Rahman ◽  
Patrick Meir ◽  
...  
Keyword(s):  
Functional Groups ◽  
Functional Diversity ◽  
Ecosystem Processes ◽  
Global Scale ◽  
Species Density ◽  
Abundance Data ◽  
Standardized Protocol ◽  
Biogeographical Distribution ◽  
Belt Transect

Abstract:Termite species and functional groups differ among regions globally (the functional-diversity anomaly). Here we investigate whether similar differences in biomass and abundance of termites occur among continents. Biomass and abundance data were collected with standardized sampling in Cameroon, Malaysia and Peru. Data from Peru were original to this study, while data from Cameroon and Malaysia were compiled from other sources. Species density data were sampled using a standardized belt transect (100 × 2 m) while the biomass and abundance measurements were sampled using a standardized protocol based on 2 × 2-m quadrats. Biomass and abundance data confirmed patterns found for species density and thus the existence of the functional diversity anomaly: highest estimates for biomass and abundance were found in Cameroon (14.5 ± 7.90 g m−2 and 1234 ± 437 ind m−2) followed by Malaysia (0.719 ± 0.193 g m−2 and 327 ± 72 ind m−2) and then Peru (0.345 ± 0.103 g m−2 and 130 ± 39 ind m−2). The biomass and abundance for each functional group were significantly different across sites for most termite functional groups. Biogeographical distribution of lineages was the primary cause for the functional diversity anomaly with true soil-feeding termites dominating in Cameroon and the absence of fungus-growing termites from Peru. These findings are important as the biomass and abundance of functional groups may be linked to ecosystem processes. Although this study allowed for comparisons between data from different regions further comparable data are needed to enhance the understanding of the role of termites in ecosystem processes on a global scale.

Spatiotemporal palaeodiversity patterns of modern crocodiles (Crocodyliformes: Eusuchia)

2019 ◽  
Vol 189 (2) ◽  
pp. 635-656 ◽  
Author(s):  
Ane De Celis ◽  
Iván Narváez ◽  
Francisco Ortega
Keyword(s):  
South America ◽  
Least Squares ◽  
Late Miocene ◽  
North American ◽  
Fossil Record ◽  
Generalized Least Squares ◽  
Global Scale ◽  
Biotic Factors ◽  
Species Dynamics ◽  
Over Time

Abstract Eusuchia is a crocodyliform clade with a rich and diverse fossil record dating back to the Mesozoic. There are several recent studies that analyse crocodyliform palaeodiversity over time, but none of them focuses exclusively on eusuchians. Thus, we estimated subsampled eusuchian palaeodiversity species dynamics over time not only at a global scale, but also by continents and main crocodylian lineages (Alligatoroidea, Crocodyloidea and Gavialoidea). These estimates reveal complex spatiotemporal palaeodiversity patterns, in which two maxima can be detected: the first during the Palaeocene and the second, which is also the biggest, in the middle-late Miocene. The Palaeocene shift is related to a North American alligatoroid diversification, whereas the middle–late Miocene maximum is related to a diversification of the three main Crocodylia lineages in Gondwanan land masses, but especially in South America. Additionally, a model-based study using generalized least squares was carried out to analyse the relationships between different abiotic and sampling proxies and eusuchian palaeodiversity. The results show that palaeotemperature is the most important factor amongst the analysed proxies, in accordance with previous studies. However, the results suggest that, along with palaeotemperature, other abiotic and/or biotic factors might also be driving eusuchian palaeodiversity dynamics.

scholarly journals Global distribution and conservation status of ecologically rare mammal and bird species

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicolas Loiseau ◽  
Nicolas Mouquet ◽  
Nicolas Casajus ◽  
Matthias Grenié ◽  
Maya Guéguen ◽  
...  
Keyword(s):  
Human Development ◽  
Rare Species ◽  
Human Development Index ◽  
Ecosystem Functioning ◽  
Conservation Status ◽  
Bird Species ◽  
Ecosystem Processes ◽  
Potential Contribution ◽  
Development Index

Abstract Identifying species that are both geographically restricted and functionally distinct, i.e. supporting rare traits and functions, is of prime importance given their risk of extinction and their potential contribution to ecosystem functioning. We use global species distributions and functional traits for birds and mammals to identify the ecologically rare species, understand their characteristics, and identify hotspots. We find that ecologically rare species are disproportionately represented in IUCN threatened categories, insufficiently covered by protected areas, and for some of them sensitive to current and future threats. While they are more abundant overall in countries with a low human development index, some countries with high human development index are also hotspots of ecological rarity, suggesting transboundary responsibility for their conservation. Altogether, these results state that more conservation emphasis should be given to ecological rarity given future environmental conditions and the need to sustain multiple ecosystem processes in the long-term.

scholarly journals Network structure of vertebrate scavenger assemblages at the global scale: drivers and ecosystem functioning implications

Ecography ◽  
2020 ◽  
Vol 43 (8) ◽  
pp. 1143-1155 ◽  
Author(s):  
Esther Sebastián‐González ◽  
Zebensui Morales‐Reyes ◽  
Francisco Botella ◽  
Lara Naves‐Alegre ◽  
Juan M. Pérez‐García ◽  
...  
Keyword(s):  
Network Structure ◽  
Ecosystem Functioning ◽  
Global Scale

scholarly journals The dilemma of controlling cultural eutrophication of lakes

2012 ◽  
Vol 279 (1746) ◽  
pp. 4322-4333 ◽  
Author(s):  
David W. Schindler
Keyword(s):  
Large Scale ◽  
Ecosystem Processes ◽  
Nutrient Fluxes ◽  
Nutrient Cycles ◽  
Case Histories ◽  
Short Term ◽  
Ecosystem Responses ◽  
Lake Recovery ◽  
Recent Claim

The management of eutrophication has been impeded by reliance on short-term experimental additions of nutrients to bottles and mesocosms. These measures of proximate nutrient limitation fail to account for the gradual changes in biogeochemical nutrient cycles and nutrient fluxes from sediments, and succession of communities that are important components of whole-ecosystem responses. Erroneous assumptions about ecosystem processes and lack of accounting for hysteresis during lake recovery have further confused management of eutrophication. I conclude that long-term, whole-ecosystem experiments and case histories of lake recovery provide the only reliable evidence for policies to reduce eutrophication. The only method that has had proven success in reducing the eutrophication of lakes is reducing input of phosphorus. There are no case histories or long-term ecosystem-scale experiments to support recent claims that to reduce eutrophication of lakes, nitrogen must be controlled instead of or in addition to phosphorus. Before expensive policies to reduce nitrogen input are implemented, they require ecosystem-scale verification. The recent claim that the ‘phosphorus paradigm’ for recovering lakes from eutrophication has been ‘eroded’ has no basis. Instead, the case for phosphorus control has been strengthened by numerous case histories and large-scale experiments spanning several decades.

scholarly journals International differences in home treatment for mental health problems

2002 ◽  
Vol 181 (5) ◽  
pp. 375-382 ◽  
Author(s):  
Tom Burns ◽  
Jocelyn Catty ◽  
Hilary Watt ◽  
Christine Wright ◽  
Martin Knapp ◽  
...  
Keyword(s):  
Mental Health ◽  
North American ◽  
American Studies ◽  
Mental Health Problems ◽  
Home Treatment ◽  
European Studies ◽  
Location Service ◽  
The Usa ◽  
Meta Analyses

BackgroundIt is perceived that North American home treatment studies reveal greater success in reducing days in hospital than do European studies. There are difficulties in extrapolating findings internationally.AimsWe aimed to determine whether North American studies find greater reductions in days in hospital and whether experimental service patients in North American studies spend less time in hospital.MethodThe results of a systematic review were analysed with respect to study location. Service components ascertained through follow-up were utilised to interpret the meta-analyses conducted.ResultsMost of the 91 studies found were from the USA and UK. North American studies found a difference of one hospital day (per patient per month) more than European studies but there was no difference in experimental data between the two locations.ConclusionsNorth American studies demonstrate greater differences in days in hospital but patients in their experimental services seem to spend no fewer days in hospital, implying a disparity in control services.

scholarly journals Research Roundup: Advocating for Children’s Rights

2018 ◽  
Vol 16 (2) ◽  
pp. 37
Author(s):  
Tess Prendergast ◽  
Betsy Diamant-Cohen ◽  
Annette Y. Goldsmith
Keyword(s):  
North American ◽  
Cultural Context ◽  
Children's Rights ◽  
Global Scale ◽  
School Libraries ◽  
Children’S Rights ◽  
North American Society ◽  
The World ◽  
Children And Childhood ◽  
American Society

Although the American Library Association and the Association for Library Service to Children are international organizations, meaning they welcome members from around the world, our scope tends to be North American in practice. While communities and funding structures in North American libraries are different (rural vs. urban for example), children’s librarians often share similar outlooks on children and childhood in general.However, while most ALSC members work within the cultural context of North American society, it is also important to understand the state of childhood on a more global scale. One way this can be accomplished is by taking a children’s rights approach. The following annotated links (many shortened through TinyUrl.com) and print resources are meant as an introduction to children’s rights for those working in public and school libraries around the world. 

scholarly journals Meta-analysis of high-latitude nitrogen-addition and warming studies imply ecological mechanisms overlooked by land models

2014 ◽  
Vol 11 (8) ◽  
pp. 12375-12414 ◽  
Author(s):  
N. J Bouskill ◽  
W. J Riley ◽  
J. Tang
Keyword(s):  
High Latitude ◽  
Field Experiments ◽  
Meta Analysis ◽  
Nitrogen Addition ◽  
Nutrient Competition ◽  
Ecosystem Responses ◽  
Nitrogen Concentrations ◽  
Ecological Mechanisms ◽  
Underlying Mechanisms ◽  
Meta Analyses

Abstract. Accurate representation of ecosystem processes in land models is crucial for reducing predictive uncertainty in energy and greenhouse gas feedbacks with the atmosphere. Here we describe an observational and modeling meta-analysis approach to benchmark land models, and apply the method to the land model CLM4.5 with two versions of belowground biogeochemistry. We focused our analysis on the above and belowground high-latitude ecosystem responses to warming and nitrogen addition, and identified mechanisms absent, or poorly parameterized in CLM4.5. While the two model versions predicted similar trajectories for soil carbon stocks following both types of perturbation, other variables (e.g., belowground respiration) differed from the observations in both magnitude and direction, indicating the underlying mechanisms are inadequate for representing high-latitude ecosystems. The observational synthesis attribute these differences to missing representations of microbial dynamics, characterization of above and belowground functional processes, and nutrient competition. We use the observational meta-analyses to discuss potential approaches to improving the current models (e.g., the inclusion of dynamic vegetation or different microbial functional guilds), however, we also raise a cautionary note on the selection of data sets and experiments to be included in a meta-analysis. For example, the concentrations of nitrogen applied in the synthesized field experiments (average =72 kg ha−1 yr−1) are many times higher than projected soil nitrogen concentrations (from nitrogen deposition and release during mineralization), which preclude a rigorous evaluation of the model responses to nitrogen perturbation. Overall, we demonstrate here that elucidating ecological mechanisms via meta-analysis can identify deficiencies in both ecosystem models and empirical experiments.

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