Community Structure & Dominance
30 Ontological Micro-Realms · Dominants, Keystones, Foundations & Species Interactions
The 30 Ontological Nodes of Realm 07
Ultra-Crisp 2-to-5-Word Architectural Portals
Ecological Dominance
- Exerting major controlling-influence
- Highest biomass concentration
- Numerical superiority control
- Governs community energy-flow
Dominant Species
- Defines community name
- Sal or Pines-forest
- Buffers local microclimate
- High abundance high-impact
Basal Area & Coverage
- Cross-sectional stem area
- Diameter breast height
- Herbage ground cover
- Canopy crown projection
Dominance Index (λ)
- Concentration of dominance
- Inverse of evenness
- Berger-Parker dominance index
- High in stressed-habitats
Monodominance vs Mixed
- Boreal single-species dominance
- Tropical multi-species sharing
- Dipterocarp ectomycorrhizal monodominance
- Latitudinal dominance shift
Subdominants & Rare Taxa
- Co-dominant secondary canopy
- Influent animal modifiers
- Long-tail rare species
- Insurance against environmental-shift
Keystone Species
- Robert Paine 1969
- Disproportionate community impact
- Low relative biomass
- Removal triggers collapse
Paine's Pisaster Proof
- Pisaster ochraceus starfish
- Controls Mytilus mussels
- Prevents mussel monoculture
- Maintains 15-species rocky-intertidal
Keystone Apex Predators
- Sea-otter suppresses urchins
- Prevents urchin barrens
- Grey-wolf Yellowstone cascade
- Mesopredator release prevention
Keystone Mutualists
- Ficus strangler figs
- Dry-season frugivore lifeline
- Mobile-linker pollinators dispersers
- Flying-fox island pollination
Keystone Modifiers
- Prairie-dog burrow towns
- African-elephant savanna clearing
- Gopher-tortoise 350-species burrows
- Beaver wetland creation
Keystone Prey & Hosts
- Antarctic krill food-base
- Pacific salmon nutrient-run
- Sustains entire guild
- High-fecundity predation resilience
Foundation Species
- Paul Dayton 1972
- Creates physical habitat-architecture
- High biomass high-abundance
- Corals kelps mangroves-redwoods
Ecosystem Engineers
- Jones Lawton Shachak
- Autogenic own body-tissue
- Allogenic mechanical transformation
- Woodpecker cavity excavation
Biomass–Impact Matrix
- Keystone: low-biomass high-impact
- Dominant: high-biomass proportional-impact
- Foundation: structural base-builder
- Rare: low-biomass low-impact
Umbrella & Flagship Roles
- Umbrella large home-range
- Tiger protects co-inhabitants
- Flagship charismatic ambassador
- Indicator environmental health-gauge
Community Structure Axes
- Physical vertical-horizontal zonation
- Biological richness-dominance web
- Temporal diurnal-seasonal rhythms
- Guild functional architecture
Top-Down vs Bottom-Up
- Bottom-up resource limitation
- Primary-producer nutrient control
- Top-down predator regulation
- Consumer-driven community structure
Trophic Cascades (HSS)
- Hairston Smith Slobodkin
- Green World Hypothesis
- Predators free vegetation
- Behaviorally-mediated landscape-of-fear
Interaction Matrix (+/−/0)
- Intraspecific same-species interactions
- Interspecific cross-species pairs
- Symbiotic close-living intimacy
- Harmonic versus disharmonic
Mutualism & Protocooperation
- Obligate mutualism (+/+)
- Termite gut-protozoa or-lichens
- Facultative protocooperation (+/+)
- Oxpecker-rhino or hermit-crab-anemone
Commensalism (+/0) Types
- Phoresy transport hitchhiking
- Remora-shark or barnacle-whale
- Inquilinism epiphytic orchids
- Metabiosis hermit-crab shells
Predation & Mimicry
- Cryptic camouflage coloration
- Aposematic warning signals
- Batesian harmless-copies-toxic
- Mullerian mutual-toxic co-mimics
Parasitism & Parasitoids
- Ectoparasites versus endoparasites
- Holoparasites Cuscuta Rafflesia
- Hemiparasites Santalum Viscum
- Brood-parasite cuckoo-koel
Herbivory & Plant Defense
- Mechanical thorns spines-trichomes
- Calotropis cardiac glycosides
- Alkaloids tannins terpenoids
- Induced volatile wasp-recruitment
Competition (−/−) Modes
- Exploitative scramble depletion
- Interference contest fighting
- Preemptive space occupation
- Abingdon-tortoise goat browse
Apparent Competition
- Robert Holt 1977
- Shared predator mediation
- Prey-A boosts predator-numbers
- Predator suppresses Prey-B
Amensalism & Allelopathy
- Asymmetric harm (−/0)
- Penicillium antibiosis mold
- Black-walnut juglone allelopathy
- Parthenium Lantana root-inhibitors
Facilitation & Nurse Effect
- Positive non-trophic aid
- Desert nurse-shrub shade
- Saguaro seedling protection
- Stress-Gradient Hypothesis shift
Interaction Network Strength
- Few strong links
- Many weak links
- Weak-links dampen oscillations
- Co-extinction cascade prevention
Core Ontological Distinctions
1. Dominant Species vs. Keystone Species vs. Foundation SpeciesDominant Species have high biomass/abundance and exert proportional control over energy flow (e.g., Pine trees in a pine forest). Keystone Species have low biomass/abundance but exert a disproportionately massive effect relative to their numbers (e.g., Sea otters, Pisaster starfish, Wolves). Foundation Species physically build and structure the 3D habitat frame itself (e.g., Reef-building corals, Kelp, Mangroves).
2. Batesian Mimicry vs. Müllerian MimicryIn Batesian Mimicry, a harmless, palatable species evolves to look like a toxic, dangerous model (bluffing predators). In Müllerian Mimicry, two or more genuinely unpalatable/venomous species evolve to look like each other, sharing the cost of educating predators.
3. Interference Competition vs. Exploitative vs. Apparent CompetitionInterference is direct physical aggression or allelopathy blocking access to resources. Exploitative is indirect depletion by consuming a shared limited resource faster. Apparent Competition occurs when two prey species do not share food at all, but one boosts the population of a shared predator that then decimates the other.
Realm 07 Complete
All 30 nodes of **Realm 07: Community Structure & Dominance** (`07.01` to `07.30`) are forged. Next in the **World A** sequence is **Realm 08: Stratification, Ecotones & Edge Effects** (`[008 / 266]`).