The influence of interspecific interactions on species range expansion rates.
Ongoing and predicted global change makes understanding and predicting species' range shifts an urgent scientific priority. Here, we provide a synthetic perspective on the so far poorly understood effects of interspecific interactions on range expansion rates. We present theoretical foundations for how interspecific interactions may modulate range expansion rates, consider examples from empirical studies of biological invasions and natural range expansions as well as process-based simulations, and discuss how interspecific interactions can be more broadly represented in process-based, spatiotemporally explicit range forecasts. Theory tells us that interspecific interactions affect expansion rates via alteration of local population growth rates and spatial displacement rates, but also via effects on other demographic parameters. The best empirical evidence for interspecific effects on expansion rates comes from studies of biological invasions. Notably, invasion studies indicate that competitive dominance and release from specialized enemies can enhance expansion rates. Studies of natural range expansions especially point to the potential for competition from resident species to reduce expansion rates. Overall, it is clear that interspecific interactions may have important consequences for range dynamics, but also that their effects have received too little attention to robustly generalize on their importance. We then discuss how interspecific interactions effects can be more widely incorporated in dynamic modeling of range expansions. Importantly, models must describe spatiotemporal variation in both local population dynamics and dispersal. Finally, we derive the following guidelines for when it is particularly important to explicitly represent interspecific interactions in dynamic range expansion forecasts: if most interacting species show correlated spatial or temporal trends in their effects on the target species, if the number of interacting species is low, and if the abundance of one or more strongly interacting species is not closely linked to the abundance of the target species.
( svenning@biology.au.dk ), Ecoinformatics and Biodiversity, Dept of Bioscience, Aarhus Univ., Ny Munkegade 114, DK-8000 Aarhus C, Denmark.
Jens-Christian
JC
Svenning
Dépt de biologie, chimie et géographie, Univ. du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, QC G5L 3A1, Canada.
Dominique
D
Gravel
Dept of Biology, Univ. of Florida, FL 32611, USA.
Robert D
RD
Holt
Univ. Montpellier 2, CNRS, Inst. des Sciences de l'Évolution (UMR 5554), Place Eugène Bataillon, FR-34095 Montpellier cedex 05, France, and Inst. of Biochemistry and Biology, Univ. of Potsdam, Maulbeerallee 2, DE-14469 Potsdam, Germany.
Frank M
FM
Schurr
Evolution, Modeling and Analyzing of BIOdiversity group, Laboratoire d'Ecologie Alpine, UMR CNRS 5553, Univ. Joseph Fourier, Grenoble Cedex 9, France.
Wilfried
W
Thuiller
Evolution, Modeling and Analyzing of BIOdiversity group, Laboratoire d'Ecologie Alpine, UMR CNRS 5553, Univ. Joseph Fourier, Grenoble Cedex 9, France.
Tamara
T
Münkemüller
Evolution, Modeling and Analyzing of BIOdiversity group, Laboratoire d'Ecologie Alpine, UMR CNRS 5553, Univ. Joseph Fourier, Grenoble Cedex 9, France.
Katja H
KH
Schiffers
Dept of Conservation Biology, Vegetation Ecology and Landscape Ecology, Univ. Wien, Rennweg 14, AT-1030 Vienna, Austria.
Stefan
S
Dullinger
USGS Utah Cooperative Fish and Wildlife Research Unit, Dept of Wildland Resources, 5230 Old Main Hill, Utah State Univ., Logan, UT 84322-5230, USA.
Thomas C
TC
Edwards
Biodiversity and Climate Research Centre (BiK-F), Goethe-Univ. Frankfurt, Senckenberganlage 25, DE-60325 Frankfurt am Main, Germany.
Thomas
T
Hickler
Botany Dept, Univ. of Otago, PO Box 56, Dunedin 9054, New Zealand.
Steven I
SI
Higgins
Landscape Dynamics, Swiss Federal Research Inst. WSL, Zürcherstr. 111, CH-8903 Birmensdorf, Switzerland, and Dept of Environmental System Science, Swiss Federal Inst. of Technology ETH, Universitätstrasse 16, CH-8092 Zurich, Switzerland.
Julia E M S
JE
Nabel
Univ. Montpellier 2, CNRS, Inst. des Sciences de l'Évolution (UMR 5554), Place Eugène Bataillon, FR-34095 Montpellier cedex 05, France, and Inst. of Biochemistry and Biology, Univ. of Potsdam, Maulbeerallee 2, DE-14469 Potsdam, Germany.
Jörn
J
Pagel
Landscape Dynamics, Swiss Federal Research Inst. WSL, Zürcherstr. 111, CH-8903 Birmensdorf, Switzerland.
Signe
S
Normand