Ecological Community
30 Ontological Micro-Realms · Composition, Richness, Evenness & Diversity
The 30 Ontological Nodes of Realm 06
Ultra-Crisp 2-to-5-Word Architectural Portals
Community (Biocenosis)
- Karl Mobius 1877
- Multi-species interacting assemblage
- Shared geographic habitat
- Living ecosystem component
Biocenosis Triad
- Phytocenosis plant assemblage
- Zoocenosis animal assemblage
- Microbocenosis microbial decomposer-web
- Integrated functional triad
Major vs Minor Communities
- Major self-sustaining unit
- Direct solar independence
- Minor dependent society
- Fallen-log or cow-dung-mat
Clementsian Superorganism
- Frederic Clements 1916
- Holistic superorganism view
- Co-evolved tightly-bound species
- Discrete community boundaries
Gleasonian Continuum
- Henry Gleason 1926
- Individualistic species response
- Chance dispersal assembly
- Continuous gradient overlap
Open vs Closed Communities
- Opendiffuse ecocline boundaries
- Independent species distributions
- Closed sharp ecotones
- Serpentine soil boundaries
Species Composition
- Taxonomic identity roster
- Complete floristic-faunistic inventory
- Distinguishes equal-richness sites
- Diagnostic indicator taxa
Species Richness (S)
- Total species count
- Ignores relative abundance
- Margalef and Menhinick-indices
- Sample-size sensitivity
Relative Abundance (pi)
- Individuals per species
- Proportional representation (ni/N)
- Common versus rare-taxa
- Log-normal abundance distribution
Species Evenness (J')
- Equitability of distribution
- Pielou evenness index
- High-evenness uniform proportions
- Low-evenness single-species monopoly
Species Diversity Dualism
- Richness plus evenness
- Heterogeneity composite metric
- Uncertainty of encounter
- Effective species number
Shannon–Wiener Index (H')
- Information-theory entropy metric
- Sensitive to rare-species
- Typical range 1.5–3.5
- Increases with equitability
Simpson's Index (D)
- Probability of same-species-draw
- Weighted toward common-dominants
- Complement index (1-D)
- Reciprocal index (1/D)
Alpha, Beta & Gamma
- Robert Whittaker 1960
- Alpha within-habitat diversity
- Beta between-habitat turnover
- Gamma regional landscape-pool
Rank–Abundance Curves
- Whittaker dominance-diversity plots
- Curve length shows-richness
- Slope steepness shows-evenness
- Geometric broken-stick models
Species–Area Curve (S=cA^z)
- Alexander von Humboldt
- Log-log linear slope-z
- Mainland z = 0.1–0.2
- Frugivorous island z-steepening
Rarefaction & Collector Curves
- Standardizing unequal sample-sizes
- Asymptotic completeness plateau
- Chao-1 unseen species-estimator
- Sampling effort calibration
Raunkiaer's Life Forms
- Perennating bud height
- Phanerophytes and chamaephytes
- Hemicryptophytes and cryptophytes
- Therophytes annual seeds
Quantitative Characters
- Quadrat density per-area
- Frequency percentage occurrence
- Abundance in occupied-quadrats
- Canopy basal cover
Raunkiaer's Frequency Law
- Five frequency classes (A–E)
- J-shaped double-peak curve
- A > B > C >=< D < E
- Tests community homogeneity
Importance Value Index (IVI)
- Curtis and McIntosh
- Relative Density (RD)
- Relative Frequency (RF)
- Relative Dominance (RDo)
Qualitative Characters
- Physiognomy external appearance
- Phenology seasonal timing
- Sociability clumping degree
- Vitality reproductive vigor
Fidelity & Phytosociology
- Josias Braun-Blanquet school
- Faithfulness to community
- Exclusive selective preferential
- Indifferent accidental strangers
Physiognomy & Growth Forms
- Overall structural architecture
- Trees shrubs herbs-lianas
- Epiphytes and bryophytes
- Leaf-size evergreenness spectrum
Phenology & Aspection
- Seasonal life-cycle calendar
- Bud-burst flowering fruiting
- Prevernal vernal aestival
- Serotinal autumnal hibernal
Sociability & Vitality
- Braun-Blanquet S1–S5 scale
- Solitary stems to-pure-mats
- V1–V4 reproductive vitality
- Seed-set completion success
Community Organization
- Food-web connectance density
- Compartmentalized interaction modules
- Bottom-up nutrient control
- Top-down predator cascades
Assembly & Filtering Rules
- Regional species pool
- Dispersal filter barrier
- Abiotic environmental sieve
- Biotic interaction filter
Similarity Indices
- Sorensen index 2C/(A+B)
- Jaccard coefficient overlap
- Bray-Curtis abundance dissimilarity
- Community ordination clustering
Diversity–Stability Debate
- Elton-MacArthur stability hypothesis
- Robert May complexity-paradox
- Tilman portfolio effect
- Rivet-popper redundancy model
Core Ontological Distinctions
1. Species Richness vs. Species Evenness vs. Species DiversitySpecies Richness (S) is simply the raw count of different species present. Species Evenness (J') measures how equally individuals are distributed among those species. Species Diversity (H' or D) combines both: if Forest A and Forest B both have 10 tree species, but Forest A is 91% one species while Forest B has 10% of each, they have identical richness, but Forest B has vastly higher evenness and diversity.
2. Alpha (α) vs. Beta (β) vs. Gamma (γ) DiversityAlpha Diversity is local diversity within a single uniform habitat patch. Beta Diversity measures the rate of species turnover (replacement) as you move from one habitat to another along a gradient. Gamma Diversity is the total regional diversity across all habitats in a broad landscape.
3. Clementsian (Closed) vs. Gleasonian (Open) CommunityClements (1916) viewed a community as a tightly bound, co-evolved "superorganism" with sharp boundaries. Gleason (1926) proved that most communities are "open" continuums where each species responds individualistically to abiotic gradients according to its own tolerance range.
Realm 06 Complete
All 30 nodes of **Realm 06: Ecological Community** (`06.01` to `06.30`) are forged. We are halfway through **World A** and ready for **Realm 07: Community Structure & Dominance** (`[007 / 266]`).