Ecology Design — The Web of Life
Most fictional worlds have predators and prey and nothing else. Real ecosystems have decomposers, scavengers, parasites, filter-feeders, symbiotes, and organisms that exist in niches no one thinks about until they're missing. A world with wolves and deer but no fungi is a world where nothing rots — and that's a world that collapses.
This skill provides the framework for designing ecosystems that feel complete, even if you only show 10% of them to the reader (the iceberg principle).
The Getz 10-Niche Model
Wayne Getz's biomass transformation web organizes all organisms along three axes:
┌─────────── GATHERER (mobile) ──────────┐
│ │
Eats plants Eats animals Eats dead matter
┌─────────┐ ┌──────────┐ ┌───────────────┐
│Victivore│ │Bestivore │ │ Carcasivore │
│(deer, │ │(wolf, │ │ (vulture, │
│ rabbit) │ │ hawk) │ │ hyena) │
└─────────┘ └──────────┘ └───────────────┘
┌─────────── MINER (stationary) ─────────┐
│ │
Eats plants Eats animals Eats dead matter
┌─────────┐ ┌──────────┐ ┌───────────────┐
│Lectivore│ │Zotanophg.│ │ Thanatophage │
│(caterpil│ │(barnacle,│ │ (dung beetle, │
│ lar) │ │ anemone) │ │ carrion grub)│
└─────────┘ └──────────┘ └───────────────┘
Plus:
┌──────────┐ ┌──────────┐ ┌──────────┐ ┌──────────┐
│Detritivor│ │Sarcophage│ │Necrophage│ │Decomposer│
│(worm, │ │(parasite │ │(parasite │ │(fungus, │
│ millipede│ │ on live │ │ on dead │ │ bacteria)│
│ │ │ hosts) │ │ hosts) │ │ │
└──────────┘ └──────────┘ └──────────┘ └──────────┘
The 10 Niches
| Niche |
Role |
Real Example |
Fantasy Potential |
| Victivore |
Mobile plant-eater |
Deer, grasshopper |
Grazing beasts that migrate with seasons |
| Lectivore |
Stationary plant-eater |
Caterpillar, aphid |
Creatures that embed in crystal-trees and feed |
| Bestivore |
Mobile predator |
Wolf, hawk, spider |
Apex predators, pack hunters |
| Zotanophage |
Stationary predator |
Barnacle, venus flytrap |
Ambush organisms, trap-builders |
| Carcasivore |
Mobile scavenger |
Vulture, hyena |
Creatures that follow armies, haunt battlefields |
| Thanatophage |
Stationary scavenger |
Dung beetle, carrion grub |
Organisms in ruins, feeding on decay |
| Detritivore |
Particle consumer |
Earthworm, millipede |
Soil-makers, the invisible foundation |
| Sarcophage |
Parasite on living hosts |
Tapeworm, tick |
Creatures that feed on magic-users, or on cursed energy |
| Necrophage |
Parasite on dead matter |
Certain fungi on corpses |
Organisms that grow on the dead, transforming them |
| Decomposer |
Breaks down all dead matter |
Fungi, bacteria |
The recyclers — without them, nothing returns to the soil |
Design rule: Every ecosystem should have at least one organism in each niche. You don't need to name them all — but knowing they exist makes the 10% you show feel like it's sitting on top of a complete web.
Fantasy System Interaction
The most interesting ecological question: how does the fantasy system interact with the food web?
- If magic is ambient (like cursed energy), some organisms will have evolved to feed on it — a new energy source creates new niches
- If magic requires a rare material, organisms near deposits will evolve around it — crystal-eating insects, metal-filtering plants
- If magic can heal or resurrect, decomposers face competition — what happens to an ecosystem where nothing fully dies?
- If magic corrupts or mutates, the ecosystem near magical sites will be distorted — wrong niches, missing links, organisms that shouldn't exist
The Climate-Biome Cascade
Ecosystems don't exist randomly. They cascade from physical geography:
Latitude + Altitude + Ocean currents
│
▼
Temperature + Rainfall
│
▼
Biome Type
│
▼
Flora (plants shaped by climate)
│
▼
Fauna (animals shaped by flora + climate)
│
▼
Food Web (10 niches filled by available organisms)
│
▼
Human Use (what people harvest, hunt, cultivate)
Biome Quick Reference
| Biome |
Temperature |
Rainfall |
Key Feature |
| Tropical rainforest |
Hot year-round |
Very high |
Biodiversity maximum; vertical stratification |
| Savanna |
Hot, seasonal |
Moderate, seasonal |
Grasses dominate; large grazers and predators |
| Desert |
Hot or cold extremes |
Very low |
Adaptation to water scarcity; nocturnal life |
| Temperate forest |
Seasonal |
Moderate |
Deciduous cycles; rich soil from leaf litter |
| Taiga/Boreal |
Cold, long winters |
Low-moderate |
Coniferous; few species, high population density |
| Tundra |
Very cold |
Very low |
Permafrost; mosses and lichens; migratory animals |
| Steppe/Grassland |
Seasonal extremes |
Low-moderate |
Grasses; burrowing animals; fire-adapted |
| Wetland |
Varies |
Saturated |
Transition zones; extremely high productivity |
| Alpine |
Cold, UV-intense |
Varies |
Altitude-adapted; similar to tundra but with isolation |
| Deep ocean |
Cold, dark |
N/A |
Chemosynthetic base; pressure-adapted |
Designing a Fantasy Biome
If the fantasy system changes one physical variable, cascade the consequences:
- What changed? (e.g., "this region has ambient magical energy")
- How does that affect the base layer? (e.g., "plants grow faster and larger")
- What new niches open? (e.g., "organisms that feed on magical energy directly")
- What existing niches shift? (e.g., "predators are larger because prey is larger")
- What's the human consequence? (e.g., "agriculture is incredibly productive here — this region feeds an empire")
Ecosystem Health Indicators
When designing, check:
- Energy flow: Does energy enter (sunlight/magic) and exit (heat/entropy) the system? Closed loops are unrealistic.
- Nutrient cycling: Do dead things decompose and return nutrients? Without this, soil depletes.
- Population balance: Do predator populations lag behind prey populations? (Lotka-Volterra dynamics)
- Keystone species: Is there one species whose removal would collapse the web? These are narratively valuable.
- Edge effects: Where biomes meet, biodiversity increases. Borders are the most interesting places.
Read references/getz-model-detail.md for the full biomass transformation framework.
1---2name: ecology-design3description: Framework for designing complete, internally consistent ecosystems. Reference when creating biomes, flora, fauna, food chains, or any biological element of a world. Uses the Getz 10-niche model to ensure ecological completeness and the climate-biome cascade to derive ecosystems from geography.4---56# Ecology Design — The Web of Life78Most fictional worlds have predators and prey and nothing else. Real ecosystems have decomposers, scavengers, parasites, filter-feeders, symbiotes, and organisms that exist in niches no one thinks about until they're missing. A world with wolves and deer but no fungi is a world where nothing rots — and that's a world that collapses.910This skill provides the framework for designing ecosystems that feel complete, even if you only show 10% of them to the reader (the iceberg principle).1112## The Getz 10-Niche Model1314Wayne Getz's biomass transformation web organizes all organisms along three axes:1516```17 ┌─────────── GATHERER (mobile) ──────────┐18 │ │19 Eats plants Eats animals Eats dead matter20 ┌─────────┐ ┌──────────┐ ┌───────────────┐21 │Victivore│ │Bestivore │ │ Carcasivore │22 │(deer, │ │(wolf, │ │ (vulture, │23 │ rabbit) │ │ hawk) │ │ hyena) │24 └─────────┘ └──────────┘ └───────────────┘2526 ┌─────────── MINER (stationary) ─────────┐27 │ │28 Eats plants Eats animals Eats dead matter29 ┌─────────┐ ┌──────────┐ ┌───────────────┐30 │Lectivore│ │Zotanophg.│ │ Thanatophage │31 │(caterpil│ │(barnacle,│ │ (dung beetle, │32 │ lar) │ │ anemone) │ │ carrion grub)│33 └─────────┘ └──────────┘ └───────────────┘3435 Plus:36 ┌──────────┐ ┌──────────┐ ┌──────────┐ ┌──────────┐37 │Detritivor│ │Sarcophage│ │Necrophage│ │Decomposer│38 │(worm, │ │(parasite │ │(parasite │ │(fungus, │39 │ millipede│ │ on live │ │ on dead │ │ bacteria)│40 │ │ │ hosts) │ │ hosts) │ │ │41 └──────────┘ └──────────┘ └──────────┘ └──────────┘42```4344### The 10 Niches4546| Niche | Role | Real Example | Fantasy Potential |47|-------|------|-------------|-------------------|48| **Victivore** | Mobile plant-eater | Deer, grasshopper | Grazing beasts that migrate with seasons |49| **Lectivore** | Stationary plant-eater | Caterpillar, aphid | Creatures that embed in crystal-trees and feed |50| **Bestivore** | Mobile predator | Wolf, hawk, spider | Apex predators, pack hunters |51| **Zotanophage** | Stationary predator | Barnacle, venus flytrap | Ambush organisms, trap-builders |52| **Carcasivore** | Mobile scavenger | Vulture, hyena | Creatures that follow armies, haunt battlefields |53| **Thanatophage** | Stationary scavenger | Dung beetle, carrion grub | Organisms in ruins, feeding on decay |54| **Detritivore** | Particle consumer | Earthworm, millipede | Soil-makers, the invisible foundation |55| **Sarcophage** | Parasite on living hosts | Tapeworm, tick | Creatures that feed on magic-users, or on cursed energy |56| **Necrophage** | Parasite on dead matter | Certain fungi on corpses | Organisms that grow on the dead, transforming them |57| **Decomposer** | Breaks down all dead matter | Fungi, bacteria | The recyclers — without them, nothing returns to the soil |5859**Design rule**: Every ecosystem should have at least one organism in each niche. You don't need to name them all — but knowing they exist makes the 10% you show feel like it's sitting on top of a complete web.6061### Fantasy System Interaction6263The most interesting ecological question: **how does the fantasy system interact with the food web?**6465- If magic is ambient (like cursed energy), some organisms will have evolved to feed on it — a new energy source creates new niches66- If magic requires a rare material, organisms near deposits will evolve around it — crystal-eating insects, metal-filtering plants67- If magic can heal or resurrect, decomposers face competition — what happens to an ecosystem where nothing fully dies?68- If magic corrupts or mutates, the ecosystem near magical sites will be distorted — wrong niches, missing links, organisms that shouldn't exist6970## The Climate-Biome Cascade7172Ecosystems don't exist randomly. They cascade from physical geography:7374```75Latitude + Altitude + Ocean currents76 │77 ▼78 Temperature + Rainfall79 │80 ▼81 Biome Type82 │83 ▼84 Flora (plants shaped by climate)85 │86 ▼87 Fauna (animals shaped by flora + climate)88 │89 ▼90 Food Web (10 niches filled by available organisms)91 │92 ▼93 Human Use (what people harvest, hunt, cultivate)94```9596### Biome Quick Reference9798| Biome | Temperature | Rainfall | Key Feature |99|-------|-------------|----------|-------------|100| Tropical rainforest | Hot year-round | Very high | Biodiversity maximum; vertical stratification |101| Savanna | Hot, seasonal | Moderate, seasonal | Grasses dominate; large grazers and predators |102| Desert | Hot or cold extremes | Very low | Adaptation to water scarcity; nocturnal life |103| Temperate forest | Seasonal | Moderate | Deciduous cycles; rich soil from leaf litter |104| Taiga/Boreal | Cold, long winters | Low-moderate | Coniferous; few species, high population density |105| Tundra | Very cold | Very low | Permafrost; mosses and lichens; migratory animals |106| Steppe/Grassland | Seasonal extremes | Low-moderate | Grasses; burrowing animals; fire-adapted |107| Wetland | Varies | Saturated | Transition zones; extremely high productivity |108| Alpine | Cold, UV-intense | Varies | Altitude-adapted; similar to tundra but with isolation |109| Deep ocean | Cold, dark | N/A | Chemosynthetic base; pressure-adapted |110111### Designing a Fantasy Biome112113If the fantasy system changes one physical variable, cascade the consequences:1141151. **What changed?** (e.g., "this region has ambient magical energy")1162. **How does that affect the base layer?** (e.g., "plants grow faster and larger")1173. **What new niches open?** (e.g., "organisms that feed on magical energy directly")1184. **What existing niches shift?** (e.g., "predators are larger because prey is larger")1195. **What's the human consequence?** (e.g., "agriculture is incredibly productive here — this region feeds an empire")120121## Ecosystem Health Indicators122123When designing, check:124- **Energy flow**: Does energy enter (sunlight/magic) and exit (heat/entropy) the system? Closed loops are unrealistic.125- **Nutrient cycling**: Do dead things decompose and return nutrients? Without this, soil depletes.126- **Population balance**: Do predator populations lag behind prey populations? (Lotka-Volterra dynamics)127- **Keystone species**: Is there one species whose removal would collapse the web? These are narratively valuable.128- **Edge effects**: Where biomes meet, biodiversity increases. Borders are the most interesting places.129130Read `references/getz-model-detail.md` for the full biomass transformation framework.
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