Migratory Animals Couple Biodiversity and Ecosystem Functioning Worldwide

Animal migrations span the globe, involving immense numbers of individuals from a wide range of taxa. Migrants transport nutrients, energy, and other organisms as they forage and are preyed upon throughout their journeys. These highly predictable, pulsed movements across large spatial scales render migration a potentially powerful yet underappreciated dimension of biodiversity that is intimately embedded within resident communities. We review examples from across the animal kingdom to distill fundamental processes by which migratory animals influence communities and ecosystems, demonstrating that they can uniquely alter energy flow, food-web topology and stability, trophic cascades, and the structure of metacommunities. Given the potential for migration to alter ecological networks worldwide, we suggest an integrative framework through which community dynamics and ecosystem functioning may explicitly consider animal migrations.

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Scaling up biodiversity–ecosystem functioning relationships: the role of environmental heterogeneity in space and time

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.2779 ◽

2021 ◽

Vol 288 (1946) ◽

pp. 20202779

Author(s):

Patrick L. Thompson ◽

Sonia Kéfi ◽

Yuval R. Zelnik ◽

Laura E. Dee ◽

Shaopeng Wang ◽

...

Keyword(s):

Environmental Conditions ◽

Ecosystem Functioning ◽

Environmental Heterogeneity ◽

Community Dynamics ◽

Formal Model ◽

Spatial Scales ◽

Scale Dependence ◽

Space And Time ◽

Number Of Species

The biodiversity and ecosystem functioning (BEF) relationship is expected to be scale-dependent. The autocorrelation of environmental heterogeneity is hypothesized to explain this scale dependence because it influences how quickly biodiversity accumulates over space or time. However, this link has yet to be demonstrated in a formal model. Here, we use a Lotka–Volterra competition model to simulate community dynamics when environmental conditions vary across either space or time. Species differ in their optimal environmental conditions, which results in turnover in community composition. We vary biodiversity by modelling communities with different sized regional species pools and ask how the amount of biomass per unit area depends on the number of species present, and the spatial or temporal scale at which it is measured. We find that more biodiversity is required to maintain functioning at larger temporal and spatial scales. The number of species required increases quickly when environmental autocorrelation is low, and slowly when autocorrelation is high. Both spatial and temporal environmental heterogeneity lead to scale dependence in BEF, but autocorrelation has larger impacts when environmental change is temporal. These findings show how the biodiversity required to maintain functioning is expected to increase over space and time.

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

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2019.0354 ◽

2020 ◽

Vol 378 (2181) ◽

pp. 20190354 ◽

Cited By ~ 1

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’.

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Scaling up biodiversity ecosystem functioning relationships: the role of environmental variability in space and time

10.1101/2020.11.04.367250 ◽

2020 ◽

Author(s):

Patrick L. Thompson ◽

Sonia Kéfi ◽

Yuval R. Zelnik ◽

Laura E. Dee ◽

Shaopeng Wang ◽

...

Keyword(s):

Environmental Conditions ◽

Ecosystem Functioning ◽

Community Dynamics ◽

Environmental Variability ◽

Formal Model ◽

Spatial Scales ◽

Environmental Variation ◽

Scale Dependence ◽

Temporal Scale ◽

Number Of Species

AbstractThe biodiversity and ecosystem functioning (BEF) relationship is expected to depend on the spatial or temporal scale at which it is measured. Environmental variation is hypothesized to explain this scale dependence because it influences how quickly biodiversity accumulates with scale. However, this link has yet to be demonstrated in a formal model. Here we use a Lotka-Volterra competition model to simulate community dynamics when environmental conditions vary across either space or time. Species differ in their optimal environmental conditions, which results in turnover in community composition. We vary biodiversity by modelling communities with different sized regional species pools and ask how the amount of biomass per unit area depends on the number of species present, and the spatial or temporal scale at which it is measured. We find that more biodiversity is required to maintain functioning at larger temporal and spatial scales. The number of species required increases quickly when environmental autocorrelation is low, and slowly when autocorrelation is high. Both spatial and temporal environmental variation led to scale dependence in BEF, but autocorrelation had larger impacts when environmental change was temporal. These findings show how the biodiversity required to maintain functioning is expected to increase over time and space.

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Hindcasting Ecosystem Functioning Change in an Anthropogenized Estuary: Implications for an Era of Global Change

Frontiers in Marine Science ◽

10.3389/fmars.2021.747833 ◽

2021 ◽

Vol 8 ◽

Author(s):

Xiaoyu Fang ◽

Francesco Cozzoli ◽

Sven Smolders ◽

Antony Knights ◽

Tom Moens ◽

...

Keyword(s):

Oxygen Uptake ◽

Ecosystem Functioning ◽

Anthropogenic Activities ◽

Spatial Scales ◽

Metabolic Model ◽

Distribution Model ◽

Soft Sediment ◽

Hediste Diversicolor ◽

Ecosystem Integrity ◽

Integrative Framework

Understanding how altered hydrodynamics related to climate change and anthropogenic modifications affect ecosystem integrity of shallow coastal soft-sediment environments requires a sound integration of how species populations influence ecosystem functioning across heterogeneous spatial scales. Here, we hindcasted how intertidal habitat loss and altered hydrodynamic regimes between 1955 and 2010 associated with geomorphological change to accommodate expansion in anthropogenic activities in the Western Scheldt altered spatial patterns and basin-wide estimates of ecosystem functioning. To this end we combined an empirically derived metabolic model for the effect of the common ragworm Hediste diversicolor on sediment biogeochemistry (measured as sediment oxygen uptake) with a hydrodynamic and population biomass distribution model. Our integrative modeling approach predicted an overall decrease by 304 tons in ragworm biomass between 1955 and 2010, accounting for a reduction by 28% in stimulated sediment oxygen uptake at the landscape scale. Local gains or losses in habitat suitability and ecosystem functioning were primarily driven by changes in maximal current velocities and inundation regimes resulting from deepening, dredging and disposal practices. By looking into the past, we have demonstrated how hydro- and morphodynamic changes affect soft-sediment ecology and highlight the applicability of the integrative framework to upscale anticipated population effects on ecosystem functioning.

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Reducing the Eltonian shortfall with trophic interaction models

10.22541/au.163251144.42146962/v1 ◽

2021 ◽

Author(s):

Dominique Caron ◽

Luigi Maiorano ◽

Wilfried Thuiller ◽

Laura J. Pollock

Keyword(s):

Food Web ◽

Food Webs ◽

Functional Traits ◽

Conservation Planning ◽

Ecosystem Functioning ◽

Species Interactions ◽

Large Scale ◽

Spatial Scales ◽

Functional Trait ◽

Predator Prey

While species interactions are fundamental for linking biodiversity to ecosystem functioning and for conservation, large-scale empirical data are lacking for most species and ecosystems. Accumulating evidence suggests that trophic interactions are predictable from available functional trait information, but we have yet to understand how well we can predict interactions across large spatial scales and food webs. Here, we built a model predicting predator-prey interactions based on functional traits for European vertebrates. We found that even models calibrated with very few known interactions (100 out of 71k) estimated the entire food web reasonably well. However, predators were easier to predict than prey, with prey in some clades being particularly difficult to predict (e.g., fowls and storks). Local food web connectance was also consistently over-estimated. Our results demonstrate the potential for filling gaps in sparse food webs, an important step towards a better description of biodiversity with strong implications for conservation planning.

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Faculty Opinions recommendation of Humans strengthen bottom-up effects and weaken trophic cascades in a terrestrial food web.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718009604.793495007 ◽

2014 ◽

Author(s):

Justin Brashares ◽

Kaitlyn Gaynor

Keyword(s):

Food Web ◽

Trophic Cascades ◽

Bottom Up

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On the generation of internal waves by river plumes in subcritical initial conditions

Scientific Reports ◽

10.1038/s41598-021-81464-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

R. Mendes ◽

J. C. B. da Silva ◽

J. M. Magalhaes ◽

B. St-Denis ◽

D. Bourgault ◽

...

Keyword(s):

Numerical Modeling ◽

Internal Waves ◽

Coastal Waters ◽

Initial Conditions ◽

Spatial Scales ◽

River Plumes ◽

Wide Range ◽

Near Shore ◽

Generation Mechanisms ◽

Douro River

AbstractInternal waves (IWs) in the ocean span across a wide range of time and spatial scales and are now acknowledged as important sources of turbulence and mixing, with the largest observations having 200 m in amplitude and vertical velocities close to 0.5 m s−1. Their origin is mostly tidal, but an increasing number of non-tidal generation mechanisms have also been observed. For instance, river plumes provide horizontally propagating density fronts, which were observed to generate IWs when transitioning from supercritical to subcritical flow. In this study, satellite imagery and autonomous underwater measurements are combined with numerical modeling to investigate IW generation from an initial subcritical density front originating at the Douro River plume (western Iberian coast). These unprecedented results may have important implications in near-shore dynamics since that suggest that rivers of moderate flow may play an important role in IW generation between fresh riverine and coastal waters.

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Evidence for Ecosystem-Level Trophic Cascade Effects Involving Gulf Menhaden (Brevoortia patronus) Triggered by the Deepwater Horizon Blowout

Journal of Marine Science and Engineering ◽

10.3390/jmse9020190 ◽

2021 ◽

Vol 9 (2) ◽

pp. 190

Author(s):

Jeffrey Short ◽

Christine Voss ◽

Maria Vozzo ◽

Vincent Guillory ◽

Harold Geiger ◽

...

Keyword(s):

Food Web ◽

Mississippi River ◽

Trophic Cascade ◽

Oil Spills ◽

Net Primary Production ◽

Spatial Scales ◽

Dominant Role ◽

Deepwater Horizon ◽

Predator Species ◽

Brevoortia Patronus

Unprecedented recruitment of Gulf menhaden (Brevoortia patronus) followed the 2010 Deepwater Horizon blowout (DWH). The foregone consumption of Gulf menhaden, after their many predator species were killed by oiling, increased competition among menhaden for food, resulting in poor physiological conditions and low lipid content during 2011 and 2012. Menhaden sampled for length and weight measurements, beginning in 2011, exhibited the poorest condition around Barataria Bay, west of the Mississippi River, where recruitment of the 2010 year class was highest. Trophodynamic comparisons indicate that ~20% of net primary production flowed through Gulf menhaden prior to the DWH, increasing to ~38% in 2011 and ~27% in 2012, confirming the dominant role of Gulf menhaden in their food web. Hyperabundant Gulf menhaden likely suppressed populations of their zooplankton prey, suggesting a trophic cascade triggered by increased menhaden recruitment. Additionally, low-lipid menhaden likely became “junk food” for predators, further propagating adverse effects. We posit that food web analyses based on inappropriate spatial scales for dominant species, or solely on biomass, provide insufficient indication of the ecosystem consequences of oiling injury. Including such cascading and associated indirect effects in damage assessment models will enhance the ability to anticipate and estimate ecosystem damage from, and provide recovery guidance for, major oil spills.

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