indirect effects affects ecosystem dynamics
DESCRIPTION
This presentation is the result of a one-week student group work during the Southerm-Summer School on Mathematical-Biology, held in São Paulo, BR, in January 2012, http://www.ictp-saifr.org/mathbioTRANSCRIPT
Indirect effects affects ecosystem Indirect effects affects ecosystem dynamicsdynamics
The effect of nonlethal effects in planktonic community
Alessandra Lütz; Garcia Guillerme, Maikol Rodriguez, Thiago Couto, Caio Graciani, Angel Segura
BiodiversityBiodiversity
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David M. Hillis, Derrick Zwickl, and Robin Gutell, University of Texas.
Energy flowEnergy flow
Ecosystem functioningEnergy fluxesTrophic models
Energy flowEnergy flow
Being eaten (predation)Change in prey abundanceand traitsModify community dynamics
Non Consumable Effects (NCE)Non Consumable Effects (NCE)
Traitmediated indirect effects (TMI)
Do not imply biomass removal
Trait variation: Phenotipic (size), behaviour (diel migration), etc
NCE effectsNCE effects
TMI TMI
Inducible defenses
Non Consumable Effects (NCE)Non Consumable Effects (NCE)
Traitmediated indirect effects (TMI)Not new (Science 1971)
How relevant are NCEs to How relevant are NCEs to community dynamics?community dynamics?
NCE are relevant for predator NCE are relevant for predator prey dynamicsprey dynamicsSmall experimental systemsRelevant (Significative change)Planktonic
Plankton dynamicsPlankton dynamicsMicrobial primary producersCells or coloniesHundreds of species Carbon sinking
Fast generation time (days)Easy to handleLarge size range
Plankton dynamicsPlankton dynamicsToxic bloomsEcosystems integrityBiodiversity lossHuman
NCE in planktonNCE in planktonWidely recognized
Seldomly taken into accountSeldomly taken into accountFew models include explicitly it effects
Long term dynamics of this effect unexplored
Are NCE effects important for Are NCE effects important for community dynamics?community dynamics?
Hipothesis:Hipothesis:Inducible defenses modify community Inducible defenses modify community dynamics because of changes in biomass dynamics because of changes in biomass fluxes mediated by NCEfluxes mediated by NCE
Objective Objective Analyse community dynamics when species Analyse community dynamics when species shown inducible defenses behaviourshown inducible defenses behaviour
Planktonic systemsPlanktonic systemsLots of information on basic physiologyMorphology based functional groupsNutrient (P limited)
Group VIIGroup I
Planktonic systemsPlanktonic systemsLots of information on basic physiologyMorphology based functional groupsNutrient (P limited)
Group VIIGroup I
Kruk et al., 2010
How to ensamble the “system”?How to ensamble the “system”?
Predator “Daphnia” Limiting resource PhosporusCompeting species
How to ensamble the “system”?How to ensamble the “system”?
Predator “Daphnia” Limiting resource PhosporusCompeting speciesExplicit competition
Group VII
Group I
PP
How to ensamble the “system”?How to ensamble the “system”?
Predator “Daphnia” Limiting resource PhosporusCompeting speciesExplicit competition
Group VII
Group I
PP
What if NCE?What if NCE?
Change for I to VII in the prescence of Daphnia
Group VII
Group I
PP
Lets put some maths!Lets put some maths!
Change for I to VII in the prescence of Daphnia (m)
Group VII
Group I
PP
m
How does system behaves?How does system behaves?
Change for I to VII in the prescence of Daphnia (m)
Group VII
Group I
PP
m
Changes in the fixed pointsChanges in the fixed points
Group VII
Group I
PP
mM=0 (Exclusion) m=0.4 (Coexistence)C or G>0 C,G,Z,P > 0
Group VII
Group I
PP
m
m=0 (Exclusion G) m=0.4 (Coexistence)
Sustained oscilationsSustained oscilationsImplications for biodiversity Implications for biodiversity
Group VII
Group I
PP
m
What about nature?What about nature?CoexistencepeaksCoexistencepeaks
Group VII
Group I
Group VII
Group I
PP
m
NCEs NCEs are are importantimportant
Non trivial effect Non trivial effect (Peacor et al 2012)(Peacor et al 2012)
Influence dominance and coexistenceInfluence dominance and coexistence
Explored in a mechanistic models based on Explored in a mechanistic models based on physiological principles (first time)physiological principles (first time)
Group VII
Group I
PP
mNCEs NCEs are are importantimportant
No data to compare with model outputNo data to compare with model output
Design of experiments for model evaluation Design of experiments for model evaluation and biological parametersand biological parameters
Mathemathical tools (topological aspects) Mathemathical tools (topological aspects)
Group VIIGroup I
PP
m
m>0
Group VII
Group I
PP
m
m=0
Group VII
Group I
PP
m
Group VII
Group I
PP
m
Similar behaviourSimilar behaviour
Similar patterns in simple and complex modelSimilar patterns in simple and complex model
Similar model beahviour (needs more formal Similar model beahviour (needs more formal analysis)analysis)
Other competing groups? More predators?Other competing groups? More predators?
