bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanistic reconciliation of community and invasion ecology
Authors: Latombe Guillaume , Richardson David M. , McGeoch Melodie A. , Altwegg Res , Catford Jane A. , Chase Jonathan M. , Courchamp Franck , Esler Karen J. , Jeschke Jonathan M. , Landi Pietro , Measey John , Midgley Guy F. , Minoarivelo Henintsoa O. , Rodger James G. , Hui Cang 
Published: February 2021

AbstractCommunity and invasion ecology have mostly grown independently. There is substantial overlap in the processes captured by different models in the two fields, and various frameworks have been developed to reduce this redundancy and synthesize information content. Despite broad recognition that community and invasion ecology are interconnected, a process‐based framework synthesizing models across these two fields is lacking. Here we review 65 representative community and invasion models and propose a common framework articulated around six processes (dispersal, drift, abiotic interactions, within‐guild interactions, cross‐guild interactions, and genetic changes). The framework is designed to synthesize the content of the two fields, provide a general perspective on their development, and enable their comparison. The application of this framework and of a novel method based on network theory reveals some lack of coherence between the two fields, despite some historical similarities. Community ecology models are characterized by combinations of multiple processes, likely reflecting the search for an overarching theory to explain community assembly and structure, drawing predominantly on interaction processes, but also accounting largely for the other processes. In contrast, most models in invasion ecology invoke fewer processes and focus more on interactions between introduced species and their novel biotic and abiotic environment. The historical dominance of interaction processes and their independent developments in the two fields is also reflected in the lower level of coherence for models involving interactions, compared to models involving dispersal, drift, and genetic changes. It appears that community ecology, with a longer history than invasion ecology, has transitioned from the search for single explanations for patterns observed in nature to investigate how processes may interact mechanistically, thereby generating and testing hypotheses. Our framework paves the way for a similar transition in invasion ecology, to better capture the dynamics of multiple alien species introduced in complex communities. Reciprocally, applying insights from invasion to community ecology will help us understand and predict the future of ecological communities in the Anthropocene, in which human activities are weakening species’ natural boundaries. Ultimately, the successful integration of the two fields could advance a predictive ecology that is urgently required in a rapidly changing world.
Coastal protection assessment: a tradeoff between ecological, social, and economic issues
Authors: Trégarot Ewan , Catry Thibault , Pottier Auréa , El‐Hacen El‐Hacen M. , Sidi Cheikh Mohamed Ahmed , Cornet Cindy C. , Maréchal Jean‐Philippe , Failler Pierre 
Published: February 2021

AbstractMarine coastal ecosystems are crucial to human populations in reducing disaster risk. Least Developed Countries are particularly vulnerable to the effects of climate change, such as sea‐level rise and storm surges. The Mauritanian coast, West Africa, ranks among the most vulnerable worldwide to sea‐level rise, and coastal communities in the National Park of Banc d’Arguin (PNBA) are particularly at risk. Here, we assessed the service of coastal protection in PNBA by (1) mapping the coastal marine ecosystems with Sentinel‐2 imagery and determining their spatial wave height attenuation rates; (2) assessing the vulnerability of villages and natural habitats to coastal hazard risk; and (3) assessing the applicability of coastal protection measures in the PNBA. We found that a total of 83% of the populated coastline presents a moderate to high risk of flooding and erosion, with Iwik and R’Gueiba being the most threatened villages in the PNBA. As for the ecological risk, two low‐elevated islands, which support breeding colonies of birds, are particularly vulnerable to sea‐level rise. However, in other areas, the rupture in the dune cord created new lagoons that present valuable ecological and economic interests like the Lagoon of Bellaat. Improving the comprehension of wave attenuation provided by coastal habitats, combined with identifying the vulnerability and applicability of coastal protection measures, is essential for achieving the Sendai Framework for Disaster Risk Reduction goals. In the PNBA, relocation of identified villages at risk is probably the best cost‐effective solution with the least disturbance to both breeding and wintering birds. Protection of coastal ecosystems will also ensure a continued provision of other ecosystem services, including food supply for sea dependent populations, and contribute to achieving the Paris Agreement and Sustainable Development Goals.
Enzootic plague reduces survival of Mexican woodrats (Neotoma mexicana) in Colorado
Authors: Biggins Dean E. , Ramakrishnan Shantini , Rocke Tonie E. , Williamson Judy L. , Wimsatt Jeffrey 
Published: February 2021

AbstractPlague is a flea‐vectored disease introduced to North America c. 1900. It is lethal to many American mammal species, causes major die‐offs (epizootics) in some populations, and may be ecologically disruptive even at lower interepizootic (enzootic) levels of transmission. We sought to determine the effects of enzootic plague on survival of Mexican woodrats (Neotoma mexicana) and to test the hypothesis that the causative bacterium Yersinia pestis can be maintained by a highly plague‐susceptible species like these woodrats. We compared apparent survival for woodrats in groups with and without plague management. Woodrat groups were (1) treated for vector control with an insecticide (deltamethrin), (2) vaccinated against plague, (3) treated with both vaccine and vector control, and (4) without plague management treatments. Flea prevalence on woodrats was reduced >90% in response to deltamethrin. Apparent survival during May–September, 2010, was 31.1% for non‐vaccinated adult woodrats living in deltamethrin‐treated nests, compared to 9.6% for woodrats in non‐treated nests. During May–September of 2010 and 2011, vaccinated juvenile woodrat survival was 16.8%, compared to 8.4% for non‐vaccinated juveniles. Peak numbers of woodrats captured were 139 for the first trapping session of 2010 and 76 for the first session of 2011, suggesting a population decline consistent with the relatively low estimated survival rates. Survival results suggest that this highly plague‐susceptible species can locally maintain enzootic plague while encountering substantial rates of mortality.
Allelopathy and micropredation paradigms reconcile with system stoichiometry
Authors: Cagle Sierra E. , Roelke Daniel L. , Muhl Rika W. 
Published: February 2021

AbstractAllelopathy, a type of interference competition involving exuded chemicals, has been documented for several types of organisms including terrestrial plants, aquatic macrophytes, microbes, and planktonic algae. However, due to the dynamic nature of the aquatic environment it is unclear whether allelopathy is an evolutionarily stable competition mechanism in such a setting. In this research, we consider a cosmopolitan harmful algae species, Prymnesium parvum, for which multiple ecological roles of its produced deleterious chemicals have been suggested, including broadcast allelopathy (chemicals produced and exuded) and micropredation via cell–cell interactions (chemicals produced and held within the cell). To further investigate the ecological role of the deleterious chemicals, bioassays (with phytoplankton and zooplankton target organisms) were conducted using various fractions of a P. parvum culture grown under balanced N:P stoichiometry or imbalanced, P‐reduced stoichiometry. In addition, time‐series counts were generated with cell density enumerations and observations of behavior of a mixed species culture at intervals over a 24‐h period. Our results suggest that the apparent ecological role of the chemicals in a relatively high‐density population shifts depending on system stoichiometry in regard to nitrogen and phosphorus. We show that under balanced N:P conditions, deleterious chemical production is low and cell contact mediates mortality of prey. Differently, under imbalanced, P‐reduced conditions chemical effect is high and mass mortality occurs independent of cell contact. Thus, imbalanced N:P ratios shift the apparent ecological role of the deleterious chemicals from one of micropredation to one of broadcast allelopathy. These differences likely influence bloom dynamics and result in different ecological outcomes for systems affected by blooms. Further, we suggest that these differences indicate the importance of predatory mixotrophic feeding in the evolutionary maintenance of deleterious chemical production and the occurrence of allelopathic effects as a byproduct.
Thermal conditions during embryogenesis influence metabolic rates of juvenile brown troutSalmo trutta
Authors: Durtsche Richard D. , Jonsson Bror , Greenberg Larry A. 
Published: February 2021

AbstractThe projected climate change and increase in thermal conditions in northern latitudes over the next 60 yr has the potential to alter the metabolic scope and potential fitness of aquatic ectotherms. Here, we experimentally tested if elevated egg incubation temperature affected metabolic scope in juvenile brown trout (Salmo trutta) as a phenotypically plastic response. Cohorts of brown trout from anadromous and resident crosses were raised through embryogenesis in either natural river temperatures (cold) or elevated (+3°C, warm) temperatures until they could feed exogenously. The standard metabolic rate (SMR), maximum metabolic rate (MMR), and aerobic scope (AS = MMR − SMR) of juveniles from four anadromous‐resident crosses and from both incubation temperatures were tested at 13°C. We found that metabolic measures (SMR, MMR, AS) were lower in warm than cold‐incubated fish. There was no difference in the metabolic rates of fish from different anadromous‐resident crosses. The results of this experiment are consistent with the countergradient variation hypothesis (CGV) in which phenotypic variation, in this case variation in metabolic rates, is inversely related to thermal conditions, originally proposed in relation to altitudinal or latitudinal gradients. While previous studies have related CGV to genetic differences between populations, our study shows that thermal differences encountered at the embryonic stage can produce a phenotypic pattern consistent with CGV. It is difficult to predict the consequences of these metabolic changes in a future warmer climate, as lower metabolic rates indicate that brown trout will probably expend less energy, but a reduced aerobic scope may counteract this affect, limiting their ability as a top predator and in escaping predators. Our results suggest that there are mechanisms used to adjust to elevated water temperature that can be initiated during embryogenesis. Given that there were no differences among crosses, it is likely that temperature‐induced differences are the result of plastic responses.
Nitrogen dynamics in grain cropping systems integrating multiple ecologically based management strategies
Authors: Isbell Sarah A. , Bradley Brosi A. , Morris Andrew H. , Wallace John M. , Kaye Jason P. 
Published: February 2021

AbstractNitrogen (N) management is a critical agronomic challenge, as N losses are a source of pollution affecting both waterways and air quality and a potential economic loss for farmers. One approach to N conservation is through ecologically based agricultural systems that reduce tillage and incorporate cover crops. However, these systems exhibit considerable complexity resulting in potential agronomic trade‐offs. To address these concerns, four crop management systems were implemented within an organically managed corn–soy–winter grain crop rotation. These systems varied in tillage frequency and intensity, cover crop species selection, cover crop termination and establishment methods, fertilizer management, and cash crop season length. We used field measurements to investigate the impact of each system on N pools and to reveal the strengths and weaknesses of each system in addressing N provisioning services, with a focus on the supply and retention of N before and after the corn phase of the rotation. All systems had greater estimated N inputs (via manure and N‐fixation) than outputs (via crop harvest) at the end of the three‐year rotation, demonstrating the importance of prioritizing N retention in cover crops. Interactions among system components were important drivers of temporal N dynamics; cover crop species traits and timing of manure application contributed to differences in total aboveground plant biomass N among systems. For example, one cropping system which included a no‐till corn planting into a rolled cover crop mulch had soil inorganic N availability that was asynchronous with the N needs of the corn crop even though it received the same amount of N inputs as the other systems. In general, neither interseeding cover crop mixtures nor reducing tillage resulted in marked N benefits at the system level; we did not observe improved N retention from either practice in these systems, and there was no increase in N uptake by corn. What did clearly emerge from this experiment is the importance of managing for synchrony between soil inorganic N availability and cash crop N demand as influenced by the N retention capacity of cover crops and the timing of N mineralization due to tillage.
Revisiting the paradigm of shark‐driven trophic cascades in coral reef ecosystems
Authors: Desbiens Amelia A. , Roff George , Robbins William D. , Taylor Brett M. , Castro‐Sanguino Carolina , Dempsey Alexandra , Mumby Peter J. 
Published: February 2021

AbstractGlobal overfishing of higher‐level predators has caused cascading effects to lower trophic levels in many marine ecosystems. On coral reefs, which support highly diverse food webs, the degree to which top‐down trophic cascades can occur remains equivocal. Using extensive survey data from coral reefs across the relatively unfished northern Great Barrier Reef (nGBR), we quantified the role of reef sharks in structuring coral reef fish assemblages. Using a structural equation modeling (SEM) approach, we explored the interactions between shark abundance and teleost mesopredator and prey functional group density and biomass, while explicitly accounting for the potentially confounding influence of environmental variation across sites. Although a fourfold difference in reef shark density was observed across our survey sites, this had no impact on either the density or biomass of teleost mesopredators or prey, providing evidence for a lack of trophic cascading across nGBR systems. Instead, many functional groups, including sharks, responded positively to environmental drivers. We found reef sharks to be positively associated with habitat complexity. In turn, physical processes such as wave exposure and current velocity were both correlated well with multiple functional groups, reflecting how changes to energetic conditions and food availability, or modification of habitat affect fish distribution. The diversity of species within coral reef food webs and their associations with bottom‐up drivers likely buffers against trophic cascading across GBR functional guilds when reef shark assemblages are depleted, as has been demonstrated in other complex ecosystems.
Pollinator community species richness dilutes prevalence of multiple viruses within multiple host species
Authors: Fearon Michelle L. , Tibbetts Elizabeth A. 
Published: February 2021

AbstractMost pathogens are embedded in complex communities composed of multiple interacting hosts, but we are still learning how community‐level factors, such as host diversity, abundance, and composition, contribute to pathogen spread for many host–pathogen systems. Evaluating relationships among multiple pathogens and hosts may clarify whether particular host or pathogen traits consistently drive links between community factors and pathogen prevalence. Pollinators are a good system to test how community composition influences pathogen spread because pollinator communities are extremely variable and contain several multi‐host pathogens transmitted on shared floral resources. We conducted a field survey of four pollinator species to test the prevalence of three RNA viruses (deformed wing virus, black queen cell virus, and sacbrood virus) among pollinator communities with variable species richness, abundance, and composition. All three viruses showed a similar pattern of prevalence among hosts. Apis mellifera and Bombus impatiens had significantly higher viral prevalence than Lasioglossum spp. and Eucera pruinosa. In each species, lower virus prevalence was most strongly linked with greater pollinator community species richness. In contrast, pollinator abundance, species‐specific pollinator abundance, and community composition were not associated with virus prevalence. Our results support a consistent dilution effect for multiple viruses and host species. Pollinators in species‐rich communities had lower viral prevalence than pollinators from species‐poor communities, when accounting for differences in pollinator abundance. Species‐rich communities likely had lower viral prevalence because species‐rich communities contained more native bee species likely to be poor viral hosts than species‐poor communities, and all communities contained the highly competent hosts A. mellifera and B. impatiens. Interestingly, the strength of the dilution effect was not consistent among hosts. Instead, host species with low viral prevalence exhibited weaker dilution effects compared to hosts with high viral prevalence. Therefore, host species susceptibility and competence for each virus may contribute to variation in the strength of dilution effects. This study expands biodiversity–disease studies to the pollinator–virus system, finding consistent evidence of the dilution effect among multiple similar pathogens that infect “replicate” host communities.
Impact of telemedicine on the management of heart failure patients during coronavirus disease 2019 pandemic
Authors: Afonso Nogueira Marta , Ferreira Fernanda , Raposo Ana Filipa , Mónica Lurdes , Simões Dias Sara , Vasconcellos Rafael , Proença Gonçalo 
Published: February 2021

AimsChronic heart failure (HF) is a major comorbidity accounting for an increased severity and mortality related to coronavirus disease 2019 (COVID‐19). To reduce the risk of COVID‐19 in HF patients, telemedicine has been encouraged.Methods and resultsDuring the COVID‐19 pandemic, telemedical management with mainly over‐the‐phone appointments became a major strategy of follow‐up of our HF clinic patients. Previously, the large majority of patients have been seen in the hospital with direct patient‐provider contact. We compared both strategies of follow‐up, in pre‐pandemic (PPP) and pandemic (PP) periods, regarding total mortality and hospitalizations/emergency department (ED) visits due to HF exacerbation. We prospectively studied a cohort of 196 patients. The mean follow‐up time in PPP was 1.4 years. In this period, 20 patients died. In PP (follow‐up of 71 days), there was one additional death. Total mortality in the first year of follow‐up was 12.0%, matching the mortality predicted by the Meta‐Analysis Global Group in Chronic Heart Failure score. Considering hospitalizations/ED visits due to decompensated HF, there was no statistically significant difference between PPP and PP. Only one patient was diagnosed with COVID‐19.ConclusionsIn the light of an increase in telemedical management of this cohort of HF patients, we were able to maintain a low rate of admissions due to HF decompensation, without an increment in mortality. Regarding these results, we encourage the incremental use of telemedicine in HF patients in the context of this or future pandemics and also in situations in which physical consultation might not be possible due to logistic issues.
Impella versus extracorporal life support in cardiogenic shock: a propensity score adjusted analysis
Authors: Wernly Bernhard , Karami Mina , Engström Annemarie E. , Windecker Stephan , Hunziker Lukas , Lüscher Thomas F. , Henriques Jose P. , Ferrari Markus W. , Binnebößel Stephan , Masyuk Maryna , Niederseer David , Abel Peter , Fuernau Georg , Franz Marcus , Kelm Malte , Busch Mathias C. , Felix Stephan B. , Thiele Holger , Lauten Alexander , Jung Christian 
Published: February 2021

AbstractAimsThe mortality in cardiogenic shock (CS) is high. The role of specific mechanical circulatory support (MCS) systems is unclear. We aimed to compare patients receiving Impella versus ECLS (extracorporal life support) with regard to baseline characteristics, feasibility, and outcomes in CS.Methods and resultsThis is a retrospective cohort study including CS patients over 18 years with a complete follow‐up of the primary endpoint and available baseline lactate level, receiving haemodynamic support either by Impella 2.5 or ECLS from two European registries. The decision for device implementation was made at the discretion of the treating physician. The primary endpoint of this study was all‐cause mortality at 30 days. A propensity score for the use of Impella was calculated, and multivariable logistic regression was used to obtain adjusted odds ratios (aOR).In total, 149 patients were included, receiving either Impella (n = 73) or ECLS (n = 76) for CS. The feasibility of device implantation was high (87%) and similar (aOR: 3.14; 95% CI: 0.18–56.50; P = 0.41) with both systems. The rates of vascular injuries (aOR: 0.95; 95% CI: 0.10–3.50; P = 0.56) and bleedings requiring transfusions (aOR: 0.44; 95% CI: 0.09–2.10; P = 0.29) were similar in ECLS patients and Impella patients. The use of Impella or ECLS was not associated with increased odds of mortality (aOR: 4.19; 95% CI: 0.53–33.25; P = 0.17), after correction for propensity score and baseline lactate level. Baseline lactate level was independently associated with increased odds of 30 day mortality (per mmol/L increase; OR: 1.29; 95% CI: 1.14–1.45; P < 0.001).ConclusionsIn CS patients, the adjusted mortality rates of both ECLS and Impella were high and similar. The baseline lactate level was a potent predictor of mortality and could play a role in patient selection for therapy in future studies. In patients with profound CS, the type of device is likely to be less important compared with other parameters including non‐cardiac and neurological factors.