scholarly journals Warming decreases host survival with multiple parasitoids, but parasitoid performance also decreases

2021 ◽  
Author(s):  
Mélanie Thierry ◽  
Nicholas A. Pardikes ◽  
Benjamin Rosenbaum ◽  
Miguel G. Ximénez-Embún ◽  
Jan Hrček
Keyword(s):  
Ecosystem Functioning ◽  
Species Interactions ◽  
Community Dynamics ◽  
Abiotic Factors ◽  
Interactive Effects ◽  
Global Changes ◽  
Ecological Communities ◽  
Top Down ◽  
Multiple Predators ◽  
Abiotic And Biotic Factors

AbstractCurrent global changes are reshaping ecological communities and modifying environmental conditions. We need to recognize the combined impact of these biotic and abiotic factors on species interactions, community dynamics and ecosystem functioning. Specifically, the strength of predator-prey interactions often depends on the presence of other natural enemies: it weakens with competition and interference, or strengthens with facilitation. Such effects of multiple predators on prey are likely to be affected by changes in the abiotic environment, altering top-down control, a key structuring force in both natural and agricultural ecosystems. Here, we investigated how warming alters the effects of multiple predators on prey suppression using a dynamic model coupled with empirical laboratory experiments with Drosophila-parasitoid communities. While the effects of multiple parasitoids on host suppression were the average of the effects of individual parasitoid at ambient temperature, host suppression with multiple parasitoids was higher than expected under warming. Multiple parasitoid species had equivalent effect to multiple individuals of a same species. While multiple parasitoids enhanced top-down control under warming, parasitoid performance generally declined when another parasitoid was present due to competitive interactions, which could reduce top-down control in the long-term. Our study highlights the importance of accounting for interactive effects between abiotic and biotic factors to better predict community dynamics in a rapidly changing world, and better preserve ecosystem functioning and services such as biological control.

scholarly journals Environmental fluctuations restrict eco-evolutionary dynamics in predator–prey system

2015 ◽  
Vol 282 (1808) ◽  
pp. 20150013 ◽  
Author(s):  
Teppo Hiltunen ◽  
Gökçe B. Ayan ◽  
Lutz Becks
Keyword(s):  
Species Interactions ◽  
Community Dynamics ◽  
Evolutionary Dynamics ◽  
Temporal Dynamics ◽  
Rapid Evolution ◽  
Interactive Effects ◽  
Top Down ◽  
Bottom Up ◽  
Evolutionary Response ◽  
Environmental Fluctuations

Environmental fluctuations, species interactions and rapid evolution are all predicted to affect community structure and their temporal dynamics. Although the effects of the abiotic environment and prey evolution on ecological community dynamics have been studied separately, these factors can also have interactive effects. Here we used bacteria–ciliate microcosm experiments to test for eco-evolutionary dynamics in fluctuating environments. Specifically, we followed population dynamics and a prey defence trait over time when populations were exposed to regular changes of bottom-up or top-down stressors, or combinations of these. We found that the rate of evolution of a defence trait was significantly lower in fluctuating compared with stable environments, and that the defence trait evolved to lower levels when two environmental stressors changed recurrently. The latter suggests that top-down and bottom-up changes can have additive effects constraining evolutionary response within populations. The differences in evolutionary trajectories are explained by fluctuations in population sizes of the prey and the predator, which continuously alter the supply of mutations in the prey and strength of selection through predation. Thus, it may be necessary to adopt an eco-evolutionary perspective on studies concerning the evolution of traits mediating species interactions.

scholarly journals A Holling Functional Response Model for Mapping QTLs Governing Interspecific Interactions

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiao-Yu Zhang ◽  
Huiying Gong ◽  
Qing Fang ◽  
Xuli Zhu ◽  
Libo Jiang ◽  
...  
Keyword(s):  
Functional Response ◽  
Species Interactions ◽  
Community Dynamics ◽  
Interspecific Interactions ◽  
Microbial Interactions ◽  
Ecological Communities ◽  
Response Model ◽  
Ecological Interactions ◽  
Dynamic Complexity ◽  
Genome Level

Genes play an important role in community ecology and evolution, but how to identify the genes that affect community dynamics at the whole genome level is very challenging. Here, we develop a Holling type II functional response model for mapping quantitative trait loci (QTLs) that govern interspecific interactions. The model, integrated with generalized Lotka-Volterra differential dynamic equations, shows a better capacity to reveal the dynamic complexity of inter-species interactions than classic competition models. By applying the new model to a published mapping data from a competition experiment of two microbial species, we identify a set of previously uncharacterized QTLs that are specifically responsible for microbial cooperation and competition. The model can not only characterize how these QTLs affect microbial interactions, but also address how change in ecological interactions activates the genetic effects of the QTLs. This model provides a quantitative means of predicting the genetic architecture that shapes the dynamic behavior of ecological communities.

scholarly journals Long-term empirical evidence of ocean warming leading to tropicalization of fish communities, increased herbivory, and loss of kelp

2016 ◽  
Vol 113 (48) ◽  
pp. 13791-13796 ◽  
Author(s):  
Adriana Vergés ◽  
Christopher Doropoulos ◽  
Hamish A. Malcolm ◽  
Mathew Skye ◽  
Marina Garcia-Pizá ◽  
...  
Keyword(s):  
Empirical Evidence ◽  
Species Interactions ◽  
Abiotic Factors ◽  
Fish Communities ◽  
Kelp Forests ◽  
Ecological Communities ◽  
Epilithic Algae ◽  
Fish Herbivory ◽  
Eastern Australia

Some of the most profound effects of climate change on ecological communities are due to alterations in species interactions rather than direct physiological effects of changing environmental conditions. Empirical evidence of historical changes in species interactions within climate-impacted communities is, however, rare and difficult to obtain. Here, we demonstrate the recent disappearance of key habitat-forming kelp forests from a warming tropical–temperate transition zone in eastern Australia. Using a 10-y video dataset encompassing a 0.6 °C warming period, we show how herbivory increased as kelp gradually declined and then disappeared. Concurrently, fish communities from sites where kelp was originally abundant but subsequently disappeared became increasingly dominated by tropical herbivores. Feeding assays identified two key tropical/subtropical herbivores that consumed transplanted kelp within hours at these sites. There was also a distinct increase in the abundance of fishes that consume epilithic algae, and much higher bite rates by this group at sites without kelp, suggesting a key role for these fishes in maintaining reefs in kelp-free states by removing kelp recruits. Changes in kelp abundance showed no direct relationship to seawater temperatures over the decade and were also unrelated to other measured abiotic factors (nutrients and storms). Our results show that warming-mediated increases in fish herbivory pose a significant threat to kelp-dominated ecosystems in Australia and, potentially, globally.

scholarly journals A common framework for identifying linkage rules across different types of interactions

2015 ◽  
Author(s):  
Ignasi Bartomeus ◽  
Dominique Gravel ◽  
Jason Tylianakis ◽  
Marcelo Aizen ◽  
Ian Dickie ◽  
...  
Keyword(s):  
Ecosystem Functioning ◽  
Species Interactions ◽  
Community Dynamics ◽  
Developmental Stages ◽  
Environmental Gradients ◽  
Interspecific Interactions ◽  
General Structure ◽  
Species Traits ◽  
Ecological Processes ◽  
Wrong Reason

Species interactions, ranging from antagonisms to mutualisms, form the architecture of biodiversity and determine ecosystem functioning. Understanding the rules responsible for who interacts with whom, as well as the functional consequences of these interspecific interactions, is central to predicting community dynamics and stability. Species traitssensu latomay affect different ecological processes determining species interactions through a two-step process. First, ecological and life-history traits govern species distributions and abundance, and hence determine species co-occurrence, which is a prerequisite for them to interact. Second, morphological traits between co-occurring potential interaction partners should match for the realization of an interaction. Moreover, inferring functioning from a network of interactions may require the incorporation of interaction efficiency. This efficiency may be also trait-mediated, and can depend on the extent of matching, or on morphological, physiological or behavioural traits. It has been shown that both neutral and trait-based models can predict the general structure of networks, but they rarely accurately predict individual interactions, suggesting that these models may be predicting the right structure for the wrong reason. We propose to move away from testing null models with a framework that explicitly models the probability of interaction among individuals given their traits. The proposed models integrate both neutral and trait-matching constraints while using only information about known interactions, thereby overcoming problems originating from under-sampling of rare interactions (i.e. missing links). They can easily accommodate qualitative or quantitative data, and can incorporate trait variation within species, such as values that vary along developmental stages or environmental gradients. We use three case studies to show that they can detect strong trait matching (e.g. predator-prey system), relaxed trait matching (e.g. herbivore-plant system) and barrier trait matching (e.g. plant-pollinator systems). Only by elucidating which species traits are important in each process, i.e. in determining interaction establishment, frequency, and efficiency, can we advance in explaining how species interact and the consequences for ecosystem functioning.

Dynamics of Ecological Communities Following Current Retreat of Glaciers

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Gentile Francesco Ficetola ◽  
Silvio Marta ◽  
Alessia Guerrieri ◽  
Mauro Gobbi ◽  
Roberto Ambrosini ◽  
...  
Keyword(s):  
Community Dynamics ◽  
Abiotic Factors ◽  
Empirical Studies ◽  
Experimental System ◽  
Theoretical Models ◽  
Glacier Retreat ◽  
Community Formation ◽  
Annual Review ◽  
Publication Date ◽  
Ecological Communities

Glaciers are retreating globally, and the resulting ice-free areas provide an experimental system for understanding species colonization patterns, community formation, and dynamics. The last several years have seen crucial advances in our understanding of biotic colonization after glacier retreats, resulting from the integration of methodological innovations and ecological theories. Recent empirical studies have demonstrated how multiple factors can speed up or slow down the velocity of colonization and have helped scientists develop theoretical models that describe spatiotemporal changes in community structure. There is a growing awareness of how different processes (e.g., time since glacier retreat, onset or interruption of surface processes, abiotic factors, dispersal, biotic interactions) interact to shape community formation and, ultimately, their functional structure through succession. Here, we examine how these studies address key theoretical questions about community dynamics and show how classical approaches are increasingly being combined with environmental DNA metabarcoding and functional trait analysis to document the formation of multitrophic communities, revolutionizing our understanding of the biotic processes that occur following glacier retreat. Expected final online publication date for the Annual Review of Ecology, Evolution, and Systematics, Volume 52 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals An invasive herbivore structures plant competitive dynamics

2017 ◽  
Vol 13 (11) ◽  
pp. 20170374
Author(s):  
Lydia Wong ◽  
Tess Nahanni Grainger ◽  
Denon Start ◽  
Benjamin Gilbert
Keyword(s):  
Invasive Species ◽  
Indirect Effects ◽  
Species Interactions ◽  
Native Species ◽  
Community Dynamics ◽  
Aphid Species ◽  
Ecological Communities ◽  
Native Plant ◽  
Native Communities ◽  
Species Invasions

Species interactions are central to our understanding of ecological communities, but may change rapidly with the introduction of invasive species. Invasive species can alter species interactions and community dynamics directly by having larger detrimental effects on some species than others, or indirectly by changing the ways in which native species compete among themselves. We tested the direct and indirect effects of an invasive aphid herbivore on a native aphid species and two host milkweed species. The invasive aphid caused a 10-fold decrease in native aphid populations, and a 30% increase in plant mortality (direct effects). The invasive aphid also increased the strength of interspecific competition between the two native plant hosts (indirect effects). By investigating the role that indirect effects play in shaping species interactions in native communities, our study highlights an understudied component of species invasions.

scholarly journals A process-based metacommunity framework linking local and regional scale community ecology

2019 ◽  
Author(s):  
Patrick L. Thompson ◽  
Laura Melissa Guzman ◽  
Luc De Meester ◽  
Zsófia Horváth ◽  
Robert Ptacnik ◽  
...  
Keyword(s):  
Simulation Model ◽  
Community Ecology ◽  
Species Interactions ◽  
Community Dynamics ◽  
Regional Scale ◽  
Ecological Communities ◽  
Data Accessibility ◽  
Species Sorting ◽  
Wide Range ◽  
Underlying Processes

AbstractThe metacommunity concept has the potential to integrate local and regional dynamics within a general community ecology framework. To this end, the concept must move beyond the discrete archetypes that have largely defined it (e.g. neutral vs. species sorting) and better incorporate local scale species interactions and coexistence mechanisms. Here, we present a fundamental reconception of the framework that explicitly links local coexistence theory to the spatial processes inherent to metacommunity theory, allowing for a continuous range of competitive community dynamics. These dynamics emerge from the three underlying processes that shape ecological communities: 1) density-independent responses to abiotic conditions, 2) density-dependent biotic interactions, and 3) dispersal. Stochasticity is incorporated in the demographic realization of each of these processes. We formalize this framework using a simulation model that explores a wide range of competitive metacommunity dynamics by varying the strength of the underlying processes. Using this model and framework, we show how existing theories, including the traditional metacommunity archetypes, are linked by this common set of processes. We then use the model to generate new hypotheses about how the three processes combine to interactively shape diversity, functioning, and stability within metacommunities.Statement of authorshipThis project was conceived at the sTURN working group, of which all authors are members. PLT developed the framework and model with input from all authors. PLT wrote the model code. PLT and LMG performed the simulations. PLT produced the figures and wrote the first draft with input from LMG and JMC. All authors provided feedback and edits on several versions of the manuscript.Data accessibilityAll code for running the simulation model and producing the figures is archived on Zenodo - https://doi.org/10.5281/zenodo.3833035.

scholarly journals The iDiv Ecotron - a flexible research platform for multitrophic biodiversity research

2021 ◽  
Author(s):  
Anja Schmidt ◽  
Jessica Hines ◽  
Manfred Türke ◽  
François Buscot ◽  
Martin Schädler ◽  
...  
Keyword(s):  
Ecosystem Functioning ◽  
Field Experiments ◽  
Morphological Changes ◽  
Abiotic Factors ◽  
Global Environmental Change ◽  
Terrestrial Ecosystems ◽  
Ecosystem Functions ◽  
Ecological Communities ◽  
Food Web Structure ◽  
Cascading Effects

Across the globe, ecological communities are confronted with multiple global environmental change drivers, and they are responding in complex ways ranging from behavioural, physiological, and morphological changes within populations to changes in community composition and food web structure with consequences for ecosystem functioning. A better understanding of global change-induced alterations of multitrophic biodiversity and the ecosystem-level responses in terrestrial ecosystems requires holistic and integrative experimental approaches to manipulate and study complex communities and processes above and below the ground. We argue that mesocosm experiments fill a critical gap in this context, especially when based on ecological theory and coupled with microcosm experiments, field experiments, and observational studies of macroecological patterns. We describe the design and specifications of a novel terrestrial mesocosm facility, the iDiv Ecotron. It was developed to allow the setup and maintenance of complex communities and the manipulation of several abiotic factors in a near-natural way, while simultaneously measuring multiple ecosystem functions. To demonstrate the capabilities of the facility, we provide a case study. This study shows that changes in aboveground multitrophic interactions caused by decreased predator densities can have cascading effects on the composition of belowground communities. The iDiv Ecotrons technical features, which allow for the assembly of an endless spectrum of ecosystem components, create the opportunity for collaboration among researchers with an equally broad spectrum of expertise. In the last part, we outline some of such components that will be implemented in future ecological experiments to be realized in the iDiv Ecotron. Key words: food webs, biodiversity and ecosystem functioning, mesocosms, biotic interactions, lysimeters, climate chambers

scholarly journals Seasonal food webs with migrations: multi-season models reveal indirect species interactions in the Canadian Arctic tundra

2020 ◽  
Vol 378 (2181) ◽  
pp. 20190354 ◽  
Author(s):  
Chantal Hutchison ◽  
Frédéric Guichard ◽  
Pierre Legagneux ◽  
Gilles Gauthier ◽  
Joël Bêty ◽  
...  
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Ecosystem Functioning ◽  
Species Interactions ◽  
Multiple Equilibria ◽  
Community Dynamics ◽  
Static Model ◽  
Predator Prey ◽  
Summer Time ◽  
The Impact

Models incorporating seasonality are necessary to fully assess the impact of global warming on Arctic communities. Seasonal migrations are a key component of Arctic food webs that still elude current theories predicting a single community equilibrium. We develop a multi-season model of predator–prey dynamics using a hybrid dynamical systems framework applied to a simplified tundra food web (lemming–fox–goose–owl). Hybrid systems models can accommodate multiple equilibria, which is a basic requirement for modelling food webs whose topology changes with season. We demonstrate that our model can generate multi-annual cycling in lemming dynamics, solely from a combined effect of seasonality and state-dependent behaviour. We compare our multi-season model to a static model of the predator–prey community dynamics and study the interactions between species. Interestingly, including seasonality reveals indirect interactions between migrants and residents not captured by the static model. Further, we find that the direction and magnitude of interactions between two species are not necessarily accurate using only summer time-series. Our study demonstrates the need for the development of multi-season models and provides the tools to analyse them. Integrating seasonality in food web modelling is a vital step to improve predictions about the impacts of climate change on ecosystem functioning. This article is part of the theme issue ‘The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning’.

Some concluding remarks and a look ahead

2019 ◽  
pp. 334-340
Author(s):  
Gary G. Mittelbach ◽  
Brian J. McGill
Keyword(s):  
Climate Change ◽  
Community Assembly ◽  
Ecosystem Functioning ◽  
Species Interactions ◽  
Species Distributions ◽  
Ecological Communities ◽  
Look Ahead ◽  
Local And Regional Processes ◽  
Regional Processes

This chapter reflects on the successes achieved and challenges that remain in the study of ecological communities. It concludes with a discussion of research topics expected to occupy the attention of community ecologists for the next decade or so and that may yield big dividends in terms of understanding the processes that structure communities and govern their functioning. These include metacommunities and the integration of local and regional processes; the drivers of regional biodiversity; community assembly and functional traits; pathogens, parasites and natural enemies; biodiversity and ecosystem functioning; changing technology will change how we collect data; eco-evolutionary feedbacks and regional pool processes; climate change, and its effects on species distributions and species interactions; and the role of time.

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