Giorgos D. Kokkoris

Prof. Giorgos D. Kokkoris

Department of Marine Sciences, Faculty of the Environment, University of the Aegean, University Hill, Mytilene, Lesvos Island GR81100, Greece
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Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 April 2004 in Journal of Animal Ecology
Verified
Journal Article
Open access
PDF file
EBEric L. Berlow
Eric L. Berlow
ANAnje‐Margiet Neutel
Anje‐Margiet Neutel
JCJoel E. Cohen
Joel E. Cohen
PRPeter C. De Ruiter
Peter C. De Ruiter
BEBo Ebenman
Bo Ebenman
OPOwen Petchey
Owen Petchey
Summary: Recent efforts to understand how the patterning of interaction strength affects both structure and dynamics in food webs have highlighted several obstacles to productive synthesis. Issues arise with respect to goals and driving questions, methods and approaches, and placing results in the context of broader ecological theory. Much confusion stems from lack of clarity about whether the questions posed relate to community‐level patterns or to species dynamics, and to what authors actually mean by the term ‘interaction strength’. Here, we describe the various ways in which this term has been applied and discuss the implications of loose terminology and definition for the development of this field. Of particular concern is the clear gap between theoretical and empirical investigations of interaction strengths and food web dynamics. The ecological community urgently needs to explore new ways to estimate biologically reasonable model coefficients from empirical data, such as foraging rates, body size, metabolic rate, biomass distribution and other species traits. Combining numerical and analytical modelling approaches should allow exploration of the conditions under which different interaction strengths metrics are interchangeable with regard to relative magnitude, system responses, and species identity. Finally, the prime focus on predator–prey links in much of the research to date on interaction strengths in food webs has meant that the potential significance of non‐trophic interactions, such as competition, facilitation and biotic disturbance, has been largely ignored by the food web community. Such interactions may be important dynamically and should be routinely included in future food web research programmes.

1 March 2010 in Ecological Indicators
Verified
Journal Article
Closed access
IPIoannis Primpas
Ioannis Primpas
GTGeorge Tsirtsis
George Tsirtsis
MKMichael Karydis
Michael Karydis
GKGiorgos D. Kokkoris
Giorgos D. Kokkoris

1 March 1999 in Ecology Letters
Verified
Journal Article
Closed access
PDF file
GKGiorgos D. Kokkoris
Giorgos D. Kokkoris
ATA.Y. Troumbis
A.Y. Troumbis
JLJ.H. Lawton
J.H. Lawton

1 March 2002 in Journal of Animal Ecology
Verified
Journal Article
Open access
PDF file
GKGiorgos D. Kokkoris
Giorgos D. Kokkoris
VJVincent A. A. Jansen
Vincent A. A. Jansen
MLMichel Loreau
Michel Loreau
ATAndreas Y. Troumbis
Andreas Y. Troumbis
Summary: We examined the species richness of theoretical communities in relation to interaction strength between species. To do so, we used randomly constructed interaction matrices for competitive systems. To determine co‐existence, we tested for local stability and equilibrium feasibility of these theoretical assemblages. As expected, we found that a low mean species interaction strength could allow for many species to co‐exist. However, variance in the interaction strengths may alter previous results; two systems with the same mean interaction strength show markedly different diversity depending critically on the magnitude of the variance. If species are similar enough then many can co‐exist, even if they compete strongly. In addition we found that the species richness of a competitive community can greatly depend on the correlation between interaction strengths, an issue that so far has gone unreported. This correlation, a result of trade‐offs between species’ characteristics, may profoundly increase the potential for stable co‐existence of a highly species‐rich community. Competition may not be an anathema to diversity. Statistical properties of species’ interactions may be critical factors that contribute to the explanation of species diversity in natural communities.

1 August 2012 in Estuarine, Coastal and Shelf Science
Verified
Journal Article
Closed access
SGSylvaine Giakoumi
Sylvaine Giakoumi
ECEmma Cebrian
Emma Cebrian
GKGiorgos D. Kokkoris
Giorgos D. Kokkoris
EBEnric Ballesteros
Enric Ballesteros
ESEnric Sala
Enric Sala

8 May 2003 in Ecology Letters
Verified
Journal Article
Closed access
PDF file
VJVincent A. A. Jansen
Vincent A. A. Jansen
GKGiorgos D. Kokkoris
Giorgos D. Kokkoris