CROPPRO 411: Beneficial Arthropods and Microorganisms Lecture Notes

A comprehensive set of practice flashcards covering institutional orientation, ecological definitions, energy flow, and the differences between natural ecosystems and agroecosystems.

Habitat

Derived from the Latin "habitatus," it is the place or location where an organism or biological population lives, resides, or exists.

Niche

The way an organism lives within an environment, including its role, food, shelter, predators, temperature, and moisture requirements.

Mutualism

A biological mechanism involving the exchange of resources between species, such as terrestrial plants providing carbon to fungi in exchange for phosphorus.

Pseudomyrmex ferruginea

Acacia ants that defend the bull-horn acacia (Acacia cornigera) from herbivores in exchange for nutrients and shelter.

Biological balance

The interrelationships among organisms, including food web structures and the ability of ecological systems to sustain themselves over time; it is a dynamic attribute.

Diversity

The number of species present in an ecological system and the extent to which some species are threatened or endangered; it emerges through colonization, evolution, and extinction.

Food Chain

A sequence where sunlight energy is passed from producers (green plants) to primary consumers and then to secondary consumers.

Energy pyramid

Also known as an ecological or trophic pyramid, it is a graphical representation of energy flow within an ecosystem at each trophic level.

Producers (Autotrophs)

Plants and microorganisms that capture energy from sunlight via photosynthesis and occupy the bottom level of the energy pyramid.

Secondary Consumers

Carnivorous animals, such as frogs that feed on grasshoppers, occupying the third trophic level.

Tertiary Consumers

Organisms like owls, hawks, and foxes that consume primary and secondary consumers; only $0.1\%$ of solar energy absorbed by producers reaches this level.

Decomposers

Organisms that break down dead organic matter, wastes, and feces, providing nutrients back to the soil for primary producers.

Ecology

Derived from the Greek words "oikos" (house) and "logos" (science), it is the scientific study of the distribution and abundance of organisms and their interactions.

Ecosystem

Any area of nature including living organisms (biotic factors) and non-living substances (abiotic factors) interacting to produce an exchange of materials.

Abiotic Factor

Non-living resources such as space and physical characteristics of habitats including elevation, temperature, and humidity.

Guild

A group of organisms that use the same ecological resource in a similar way or species competing for the same resources in a similar manner.

Stability

The capacity of an ecosystem to stabilize itself and return to its original state after a disturbance occurs.

Biological magnification

The progressive increase in chemical concentrations (e.g., DDT) within food webs as toxic remains are consumed indirectly by organisms at higher trophic levels.

Succession

Progressive changes in community structure through time.

Basil Bensin

The American agronomist who first coined the term "agroecology" in $1928$.

Agroecosystem

A community of plants and animals modified by people for economic gain to produce food, fiber, fuel, and other products.

Natural Ecosystem vs. Agroecosystem Stability

Natural ecosystems have High stability, while agroecosystems have Low stability.

Spatial diversity (patchiness)

An element of species diversity referring to the spatial unit occupied by a species; it is generally incompatible with mechanization.

Structural diversity

Diversity characterized by physical variations such as tall vs. short or shaded vs. open, which increases habitat variety.

Intraspecific diversity

Genetic diversity within a crop species, such as multiline, synthetic hybrids, or cultivar mixes.