Assembly rules

Community assembly rules are a framework in ecology used to test and explain the often predictable occurrence of species within specific biological communities, first proposed by Jared Diamond.^[1]

Rule 1: Forbidden species combinations

The rules were developed after more than a decade of research into the avian assemblages on islands near New Guinea. The rules assert that competition is responsible for determining the patterns of assemblage composition.

The first rule is "forbidden species combinations". Diamond's hypothesis was that competition, not random immigration, was the main force structuring the species composition of islands.

So for example, the Bismarck black myzomela (Myzomela pammelaena) excludes the black sunbird (Nectarinia sericea). The Bismarck black myzomela lives on 23 of the 41 surveyed islands in the Bismarck Archipelago, but not on any of the 14 islands inhabited by the black sunbird. The two birds are about the same size, and both use their curved bills to sip nectar; Diamond argued that competition affects their distribution.^[2]

Rule 2: Reduced niche overlap

Ted Case tested the assembly rule that species occurring together on islands should have less niche overlap than random assemblages because they have undergone specialization.^[3] His study measured niche overlap of lizards on 37 islands near Baja California and compared niche overlap to the median niche overlap of computer generated random species assemblages. Case found that 30 of the 37 islands had lower niche overlap than the random assemblages and that some of the competition is due to interspecific competition.

v t e Ecology: Modelling ecosystems: Trophic components
General	Abiotic component Abiotic stress Behaviour Biogeochemical cycle Biomass Biotic component Biotic stress Carrying capacity Competition Ecosystem Ecosystem ecology Ecosystem model Green world hypothesis Keystone species List of feeding behaviours Metabolic theory of ecology Productivity Resource Restoration
Producers	Autotrophs Chemosynthesis Chemotrophs Foundation species Kinetotrophs Mixotrophs Myco-heterotrophy Mycotroph Organotrophs Photoheterotrophs Photosynthesis Photosynthetic efficiency Phototrophs Primary nutritional groups Primary production
Consumers	Apex predator Bacterivore Carnivores Chemoorganotroph Foraging Generalist and specialist species Intraguild predation Herbivores Heterotroph Heterotrophic nutrition Insectivore Mesopredators Mesopredator release hypothesis Omnivores Optimal foraging theory Planktivore Predation Prey switching
Decomposers	Chemoorganoheterotrophy Decomposition Detritivores Detritus
Microorganisms	Archaea Bacteriophage Lithoautotroph Lithotrophy Marine Microbial cooperation Microbial ecology Microbial food web Microbial intelligence Microbial loop Mycoloop Microbial mat Microbial metabolism Phage ecology
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Processes	Ascendency Bioaccumulation Cascade effect Climax community Competitive exclusion principle Consumer–resource interactions Copiotrophs Dominance Ecological network Ecological succession Energy quality Energy systems language f-ratio Feed conversion ratio Feeding frenzy Mesotrophic soil Nutrient cycle Oligotroph Paradox of the plankton Trophic cascade Trophic mutualism Trophic state index
Defense, counter	Animal coloration Anti-predator adaptations Camouflage Deimatic behaviour Herbivore adaptations to plant defense Mimicry Plant defense against herbivory Predator avoidance in schooling fish

v t e Ecology: Modelling ecosystems: Other components
Population ecology	Abundance Allee effect Consumer-resource model Depensation Ecological yield Effective population size Intraspecific competition Logistic function Malthusian growth model Maximum sustainable yield Overpopulation Overexploitation Population cycle Population dynamics Population modeling Population size Predator–prey (Lotka–Volterra) equations Recruitment Small population size Stability Resilience Resistance Random generalized Lotka–Volterra model
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Species interaction	Antibiosis Biological interaction Commensalism Community ecology Ecological facilitation Interspecific competition Mutualism Parasitism Storage effect Symbiosis
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Outline of ecology

Rule 1: Forbidden species combinations

Rule 2: Reduced niche overlap

Testing and alternative theories

References

Further reading

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