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Titles. Self-assembling plants and integration across ecological scales. Roderick Hunt ( Exeter, UK ) Ric Colasanti ( Corvallis, OR ). with acknowledgements to. Philip Grime ( Sheffield, UK ) Andrew Askew ( Sheffield, UK ). Presentation ready. Community image.
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Titles Self-assembling plants and integration across ecological scales Roderick Hunt (Exeter, UK) Ric Colasanti (Corvallis, OR) with acknowledgements to Philip Grime (Sheffield, UK) Andrew Askew (Sheffield, UK) Presentation ready
Community image A community of self-assembling virtual plants patches of resource depletion showing above- and below-ground
CSR type, frame 1 A single propagule … … about to grow
ditto f. 20 Abundant growth above- and below-ground … … with zones of resource depletion
Binary tree diagram Above-ground binary tree ( = shoot system) Each plant is built like this … A branching module Above-ground array Above-ground binary tree base module Below-ground array Below-ground binary tree base module … only a diagram, not a painting ! An end module Below-ground binary tree ( = root system)
Explanation End-modules capture resources: Light and carbon dioxide from above-ground Water and nutrients from below-ground Parent or offspring modules can pass resources to any adjoining modules … so whole plants can grow
Explanation The virtual plants interact with their environment and neighbours They possess most properties of real individuals and populations For example …
Validation Size Time Partitioning between root and shoot S-shaped growth curves Allometric coefficient Individual size Self-thinning line Foraging towards resources Population density Below-ground resource Functional equilibria Self-thinning in crowded populations
Explanation The foregoing plants all have the same functional specification (modular rulebase) … not yet comparative plant ecology ! But specifications can be changed if we want some plants to behave differently … … and we can simulate plant functional types
Definitions Some working definitions … Species within one functionalgroup share a single important trait Species within one functionaltype share a similar set of traits.
Implications … and some implications Functional types are multi-species levels of organization, lying above the population but below the community A single species can simultaneously be a member of several functional groups, e.g. both ‘legume’ and ’woody’ … … but a member of only one functional type, e.g. ‘K-strategist’
Why use? Why use functional types? They reduce the high dimensionality of real plant life “ There are many more actors on the stage than roles that can be played ”
... continued PFTs give a continuous view of vegetation even when relative abundances and identities of species are in flux Tools exist to allocate types to species (and type-mixes to whole communities) Large-scale (or cross-scale) studies of effects of environment or management on (e.g.) biodiversity, vulnerability and stability become possible
PFTs in CA How do we recreate basic PFTs within the self-assembling model ? … we change the modular rulebases controlling morphology, physiology and reproduction … … but we must begin to model at a high enough level to get “ airborne ” ... we need access to the emergent properties
Building blocks So we don’t build with these … we build with these !
Specifications Building a set of PFTs … Type Morphology Physiology Reproduction module size, tissue longevity, flowering speed, resource demand RGR, SLA, allocation, decomposability propagule size 1 Large Fast Slow 2 Small Slow Slow 3 Small Fast Fast 4 Medium Medium Slow 5 Small Medium Medium 6 Medium Fast Medium 7 Medium Medium Medium
Explanation Three levels in each of our three ‘ super-traits ’ = 27 possible PFTs … … but we model only 7 types the other 20 would include Darwinian Demons that do not respect evolutionary tradeoffs
Explanation Competition between two different types of plant …
R-CSR-R, frame 1 Small size, rapid growth and fast reproduction Medium size, moderately fast in growth and reproduction
ditto f. 9 (Red enters its 2nd generation)
