scholarly journals Environmentally triggered evolutionary cascade across trophic levels in an experimental phage-bacteria-insect system

2019 ◽  
Author(s):  
Matthieu Bruneaux ◽  
Roghaieh Ashrafi ◽  
Ilkka Kronholm ◽  
Anni-Maria Örmälä-Odegrip ◽  
Juan A. Galarza ◽  
...  
Keyword(s):  
Environmental Effects ◽  
Large Scale ◽  
Environmental Changes ◽  
Galleria Mellonella ◽  
Biotic Interactions ◽  
Trophic Levels ◽  
Lytic Cycle ◽  
Biological Interactions ◽  
Insect Host ◽  
Cascading Effects

AbstractEnvironmental changes can cause strong cascading effects in species communities due to altered biological interactions between species (Zarnetske et al., 2012). Highly specialized interactions arising from the co-evolution of hosts and parasites, such as bacteria and phages, and short generation times of these species could rapidly lead to considerable evolutionary changes in their biotic interactions (Kerr, 2012; Buck and Ripple, 2017), with potential large-scale ramifications to other trophic levels. Here we report experimental evidence of cascading environmental effects across trophic levels in an experimental system where phage-bacteria coevolution in an abiotically altered environment cascaded on bacterial virulence in an insect host. We found that the lytic cycle of the temperate phage KPS20 induced at low temperatures led to selection in the bacterial host Serratia marcescens that tempered the likelihood of triggering the phage’s lytic cycle. These changes in S. marcescens concomitantly attenuated its virulence in an insect host, Galleria mellonella. In addition, our data suggests that this effect is mediated by mutations and epigenetic modifications of bacterial genes moderating the onset of the temperate phage’s lytic cycle. Given the abundance of temperate phages in bacterial genomes (Canchaya et al., 2003), the sensitivity of the onset of their lytic cycle to environmental conditions (Howard-Varona et al., 2017), and the predominance of environmental change due to climate change, our results warrants attention as a cautionary example of the dangers of predicting environmental effects on species without considering complex biotic interactions.

scholarly journals Cascading Effects of Moth Outbreaks on Subarctic Soil Food Webs

2021 ◽  
Author(s):  
Irene Calderón-Sanou ◽  
Tamara Münkemüller ◽  
Lucie Zinger ◽  
Heidy Schimann ◽  
Nigel Gilles Yoccoz ◽  
...  
Keyword(s):  
Food Webs ◽  
Large Scale ◽  
Trophic Levels ◽  
Trophic Groups ◽  
Holistic View ◽  
Cascading Effects ◽  
Soil Food Webs ◽  
Network Analyses ◽  
Northern Fennoscandia ◽  
Belowground Diversity

Abstract The increasing severity and frequency of natural disturbances requires a better understanding of their effects on all compartments of biodiversity. In Northern Fennoscandia, recent large-scale moth outbreaks have led to an abrupt change in plant communities from birch forests dominated by dwarf shrubs to grass-dominated systems. However, the indirect effects on the belowground compartment remained unclear. Here, we combined eDNA survey of multiple trophic groups with network analyses to demonstrate that moth defoliation has far-reaching consequences on soil food webs. Following this disturbance, diversity and relative abundance of certain trophic groups declined (e.g. ectomycorrhizal fungi) while many others profited (e.g. bacterivores, omnivores) making soil food webs more diverse and structurally different. Overall, the direct and indirect consequences of moth outbreaks increased belowground diversity at different trophic levels. Our results highlight that a holistic view of ecosystems improves our understanding of cascading effects of major disturbances on soil food webs.

scholarly journals Biotic predictors complement models of bat and bird responses to climate and tree diversity in European forests

2019 ◽  
Vol 286 (1894) ◽  
pp. 20182193 ◽  
Author(s):  
Luc Barbaro ◽  
Eric Allan ◽  
Evy Ampoorter ◽  
Bastien Castagneyrol ◽  
Yohan Charbonnier ◽  
...  
Keyword(s):  
Functional Diversity ◽  
Environmental Changes ◽  
Insect Herbivory ◽  
Biotic Interactions ◽  
Trophic Levels ◽  
Explained Variance ◽  
Spider Abundance ◽  
Insect Activity ◽  
Bat Diversity ◽  
Functional Evenness

Bats and birds are key providers of ecosystem services in forests. How climate and habitat jointly shape their communities is well studied, but whether biotic predictors from other trophic levels may improve bird and bat diversity models is less known, especially across large bioclimatic gradients. Here, we achieved multi-taxa surveys in 209 mature forests replicated in six European countries from Spain to Finland, to investigate the importance of biotic predictors (i.e. the abundance or activity of defoliating insects, spiders, earthworms and wild ungulates) for bat and bird taxonomic and functional diversity. We found that nine out of 12 bird and bat diversity metrics were best explained when biotic factors were added to models including climate and habitat variables, with a mean gain in explained variance of 38% for birds and 15% for bats. Tree functional diversity was the most important habitat predictor for birds, while bats responded more to understorey structure. The best biotic predictors for birds were spider abundance and defoliating insect activity, while only bat functional evenness responded positively to insect herbivory. Accounting for potential biotic interactions between bats, birds and other taxa of lower trophic levels will help to understand how environmental changes along large biogeographical gradients affect higher-level predator diversity in forest ecosystems.

scholarly journals Widespread decline in plant diversity across six decades

2020 ◽  
Author(s):  
Eichenberg David ◽  
Diana E. Bowler ◽  
Bonn Aletta ◽  
Bruelheide Helge ◽  
Grescho Volker ◽  
...  
Keyword(s):  
Plant Species ◽  
Native Species ◽  
Large Scale ◽  
Grid Cell ◽  
Trophic Levels ◽  
Native Plant ◽  
Cascading Effects ◽  
Occurrence Data ◽  
Temporal Models ◽  
The 1960S

AbstractBased on plant occurrence data covering all parts of Germany, we investigated changes in the distribution of 2146 plant species between 1960 and 2017. We analyzed 29 million occurrence records over an area of ∼350.000 km2 on a 5 × 5 km grid using temporal and spatio-temporal models and accounting for sampling bias. Since the 1960s, more than 70% of investigated plant species showed significant declines in nation-wide occurrence. Archaeophytes (species introduced before 1492) most strongly declined but also native plant species experienced severe declines. In contrast, neophytes (species introduced after 1492) increased in their nation-wide occurrence but not homogeneously throughout the country. Our analysis suggests that the strongest declines in native species already happened in the 1960s-80s, a time frame in which usually few data exist. Increases in neophytic species were strongest in the 1990s and 2010s. Overall, the increase in neophytes did not compensate for the loss of other species, resulting in a decrease in mean grid-cell species-richness of -1.9% per decade. The decline in plant biodiversity is a widespread phenomenon occurring in different habitats and geographic regions. It is likely that this decline has major repercussions on ecosystem functioning and overall biodiversity, potentially with cascading effects across trophic levels. The approach used in this study is transferable to large-scale trend analyses using heterogeneous occurrence data.

scholarly journals Cascading effects of moth outbreaks on subarctic soil food webs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Irene Calderón-Sanou ◽  
Tamara Münkemüller ◽  
Lucie Zinger ◽  
Heidy Schimann ◽  
Nigel Gilles Yoccoz ◽  
...  
Keyword(s):  
Food Webs ◽  
Large Scale ◽  
Trophic Levels ◽  
Trophic Groups ◽  
Holistic View ◽  
Cascading Effects ◽  
Soil Food Webs ◽  
Network Analyses ◽  
Northern Fennoscandia ◽  
Belowground Diversity

AbstractThe increasing severity and frequency of natural disturbances requires a better understanding of their effects on all compartments of biodiversity. In Northern Fennoscandia, recent large-scale moth outbreaks have led to an abrupt change in plant communities from birch forests dominated by dwarf shrubs to grass-dominated systems. However, the indirect effects on the belowground compartment remained unclear. Here, we combined eDNA surveys of multiple trophic groups with network analyses to demonstrate that moth defoliation has far-reaching consequences on soil food webs. Following this disturbance, diversity and relative abundance of certain trophic groups declined (e.g., ectomycorrhizal fungi), while many others expanded (e.g., bacterivores and omnivores) making soil food webs more diverse and structurally different. Overall, the direct and indirect consequences of moth outbreaks increased belowground diversity at different trophic levels. Our results highlight that a holistic view of ecosystems improves our understanding of cascading effects of major disturbances on soil food webs.

scholarly journals Defective phagocyte association during infection of Galleria mellonella with Yersinia pseudotuberculosis is detrimental to both insect host and microbe

Virulence ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 638-653
Author(s):  
Anne Marie Krachler ◽  
Natalie Sirisaengtaksin ◽  
Pauline Monteith ◽  
C. E. Timothy Paine ◽  
Christopher J. Coates ◽  
...  
Keyword(s):  
Yersinia Pseudotuberculosis ◽  
Galleria Mellonella ◽  
Insect Host

scholarly journals Impact of the municipal merger on watershed management: a study of Lake Kasumigaura, Japan

2021 ◽  
Author(s):  
Takeshi Mizunoya ◽  
Noriko Nozaki ◽  
Rajeev Kumar Singh
Keyword(s):  
Watershed Management ◽  
Large Scale ◽  
Environmental Changes ◽  
Water Environment ◽  
Reduction Rate ◽  
Oxygen Demand ◽  
Policy Implications ◽  
Pollution Reduction ◽  
Lake Kasumigaura ◽  
The Impact

AbstractIn the early 2000s, Japan instituted the Great Heisei Consolidation, a national strategy to promote large-scale municipal mergers. This study analyzes the impact that this strategy could have on watershed management. We select the Lake Kasumigaura Basin, the second largest lake in Japan, for the case study and construct a dynamic expanded input–output model to simulate the ecological system around the Lake, the socio-environmental changes over the period, and their mutual dependency for the period 2012–2020. In the model, we regulate and control the following water pollutants: total nitrogen, total phosphorus, and chemical oxygen demand. The results show that a trade-off between economic activity and the environment can be avoided within a specific range of pollution reduction, given that the prefectural government implements optimal water environment policies, assuming that other factors constraining economic growth exist. Additionally, municipal mergers are found to significantly reduce the budget required to improve the water environment, but merger budget efficiency varies nonlinearly with the reduction rate. Furthermore, despite the increase in financial efficiency from the merger, the efficiency of installing domestic wastewater treatment systems decreases drastically beyond a certain pollution reduction level and eventually reaches a limit. Further reductions require direct regulatory instruments in addition to economic policies, along with limiting the output of each industry. Most studies on municipal mergers apply a political, administrative, or financial perspective; few evaluate the quantitative impact of municipal mergers on the environment and environmental policy implications. This study addresses these gaps.

scholarly journals Modelling Tree Growth in Monospecific Forests from Forest Inventory Data

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 753
Author(s):  
Guadalupe Sáez-Cano ◽  
Marcos Marvá ◽  
Paloma Ruiz-Benito ◽  
Miguel A. Zavala
Keyword(s):  
Tree Growth ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Carbon Sink ◽  
Size Variation ◽  
Biotic Interactions ◽  
Richards Equation ◽  
Tree Level ◽  
Forest Inventories ◽  
Large Scale Data

The prediction of tree growth is key to further understand the carbon sink role of forests and the short-term forest capacity on climate change mitigation. In this work, we used large-scale data available from three consecutive forest inventories in a Euro-Mediterranean region and the Bertalanffy–Chapman–Richards equation to model up to a decade’s tree size variation in monospecific forests in the growing stages. We showed that a tree-level fitting with ordinary differential equations can be used to forecast tree diameter growth across time and space as function of environmental characteristics and initial size. This modelling approximation was applied at different aggregation levels to monospecific regions with forest inventories to predict trends in aboveground tree biomass stocks. Furthermore, we showed that this model accurately forecasts tree growth temporal dynamics as a function of size and environmental conditions. Further research to provide longer term prediction forest stock dynamics in a wide variety of forests should model regeneration and mortality processes and biotic interactions.

scholarly journals Tree Diversity Reduces Fungal Endophyte Richness and Diversity in a Large-Scale Temperate Forest Experiment

Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 234 ◽  
Author(s):  
Eric A. Griffin ◽  
Joshua G. Harrison ◽  
Melissa K. McCormick ◽  
Karin T. Burghardt ◽  
John D. Parker
Keyword(s):  
Phylogenetic Diversity ◽  
Large Scale ◽  
High Throughput Sequencing ◽  
Spatial Scales ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Tree Diversity ◽  
Trophic Levels ◽  
Community Diversity ◽  
And Function

Although decades of research have typically demonstrated a positive correlation between biodiversity of primary producers and associated trophic levels, the ecological drivers of this association are poorly understood. Recent evidence suggests that the plant microbiome, or the fungi and bacteria found on and inside plant hosts, may be cryptic yet important drivers of important processes, including primary production and trophic interactions. Here, using high-throughput sequencing, we characterized foliar fungal community diversity, composition, and function from 15 broadleaved tree species (N = 545) in a recently established, large-scale temperate tree diversity experiment using over 17,000 seedlings. Specifically, we tested whether increases in tree richness and phylogenetic diversity would increase fungal endophyte diversity (the “Diversity Begets Diversity” hypothesis), as well as alter community composition (the “Tree Diversity–Endophyte Community” hypothesis) and function (the “Tree Diversity–Endophyte Function” hypothesis) at different spatial scales. We demonstrated that increasing tree richness and phylogenetic diversity decreased fungal species and functional guild richness and diversity, including pathogens, saprotrophs, and parasites, within the first three years of a forest diversity experiment. These patterns were consistent at the neighborhood and tree plot scale. Our results suggest that fungal endophytes, unlike other trophic levels (e.g., herbivores as well as epiphytic bacteria), respond negatively to increasing plant diversity.

scholarly journals Biological Impact of a Large-Scale Genomic Inversion That Grossly Disrupts the Relative Positions of the Origin and Terminus Loci of theStreptococcus pyogenesChromosome

2019 ◽  
Vol 201 (17) ◽  
Author(s):  
Dragutin J. Savic ◽  
Scott V. Nguyen ◽  
Kimberly McCullor ◽  
W. Michael McShan
Keyword(s):  
Dna Sequences ◽  
Parental Strain ◽  
Large Scale ◽  
Galleria Mellonella ◽  
Acute Infection ◽  
Relative Length ◽  
Published Data ◽  
Rich Medium ◽  
Content Type

ABSTRACTA large-scale genomic inversion encompassing 0.79 Mb of the 1.816-Mb-longStreptococcus pyogenesserotype M49 strain NZ131 chromosome spontaneously occurs in a minor subpopulation of cells, and in this report genetic selection was used to obtain a stable lineage with this chromosomal rearrangement. This inversion, which drastically displaces theorisite relative to the terminus, changes the relative length of the replication arms so that one replichore is approximately 0.41 Mb while the other is about 1.40 Mb in length. Genomic reversion to the original chromosome constellation is not observed in PCR-monitored analyses after 180 generations of growth in rich medium. Compared to the parental strain, the inversion surprisingly demonstrates a nearly identical growth pattern in the first phase of the exponential phase, but differences do occur when resources in the medium become limited. When cultured separately in rich medium during prolonged stationary phase or in an experimental acute infection animal model (Galleria mellonella), the parental strain and the invertant have equivalent survival rates. However, when they are coincubated together, bothin vitroandin vivo, the survival of the invertant declines relative to the level for the parental strain. The accompanying aspect of the study suggests that inversions taking place nearoriCalways happen to secure the linkage oforiCto DNA sequences responsible for chromosome partition. The biological relevance of large-scale inversions is also discussed.IMPORTANCEBased on our previous work, we created to our knowledge the largest asymmetric inversion, covering 43.5% of theS. pyogenesgenome. In spite of a drastic replacement of origin of replication and the unbalanced size of replichores (1.4 Mb versus 0.41 Mb), the invertant, when not challenged with its progenitor, showed impressive vitality for growthin vitroand in pathogenesis assays. The mutant supports the existing idea that slightly deleterious mutations can provide the setting for secondary adaptive changes. Furthermore, comparative analysis of the mutant with previously published data strongly indicates that even large genomic rearrangements survive provided that the integrity of theoriCand the chromosome partition cluster is preserved.

scholarly journals Identifying appropriate sampling and modelling approaches for analysing distributional patterns of Antarctic terrestrial arthropods along the Victoria Land latitudinal gradient

2010 ◽  
Vol 22 (6) ◽  
pp. 742-748 ◽  
Author(s):  
Tancredi Caruso ◽  
Ian D. Hogg ◽  
Roberto Bargagli
Keyword(s):  
Abiotic Factors ◽  
Relevant Literature ◽  
Biotic Interactions ◽  
Terrestrial Ecosystems ◽  
Climatic Conditions ◽  
Trophic Levels ◽  
Terrestrial Arthropods ◽  
Victoria Land ◽  
Dispersal Capability ◽  
Modelling Techniques

AbstractBiotic communities in Antarctic terrestrial ecosystems are relatively simple and often lack higher trophic levels (e.g. predators); thus, it is often assumed that species’ distributions are mainly affected by abiotic factors such as climatic conditions, which change with increasing latitude, altitude and/or distance from the coast. However, it is becoming increasingly apparent that factors other than geographical gradients affect the distribution of organisms with low dispersal capability such as the terrestrial arthropods. In Victoria Land (East Antarctica) the distribution of springtail (Collembola) and mite (Acari) species vary at scales that range from a few square centimetres to regional and continental. Different species show different scales of variation that relate to factors such as local geological and glaciological history, and biotic interactions, but only weakly with latitudinal/altitudinal gradients. Here, we review the relevant literature and outline more appropriate sampling designs as well as suitable modelling techniques (e.g. linear mixed models and eigenvector mapping), that will more adequately address and identify the range of factors responsible for the distribution of terrestrial arthropods in Antarctica.

Sign in / Sign up

Export Citation Format

Share Document