Glossary
Biome
A large naturally occurring community of flora and fauna occupying a major habitat, characterized by its distinct climate and dominant plant life.
Example:
The desert biome presents unique challenges for survival, with its extreme temperatures and scarce water resources.
Carrying Capacity (K)
The maximum population size of a particular species that a given environment can sustain indefinitely, given the available resources.
Example:
The carrying capacity (K) of a small island for a deer population might be limited by the amount of edible vegetation available.
Competition
The struggle between organisms for limited resources such as food, water, territory, or mates.
Example:
When two different species of squirrels try to gather acorns from the same oak tree, they are engaging in competition for food resources.
Environmental Resistance
Factors in the environment that limit population growth, such as limited food, water, space, predation, disease, or competition.
Example:
As a deer population grows, increased predation and limited winter forage act as environmental resistance, slowing its growth.
Exponential growth
Population growth that occurs at a constant rate, leading to a rapid, accelerating increase in population size, often depicted as a J-shaped curve.
Example:
In ideal laboratory conditions with abundant nutrients, a bacterial colony can exhibit exponential growth, doubling its numbers every few hours.
Intrinsic Rate of Increase (r)
The maximum potential growth rate of a population under ideal conditions, with unlimited resources and no environmental resistance.
Example:
A species with a high intrinsic rate of increase (r), like rabbits, can quickly rebound from population declines if conditions are favorable.
J-Curve
The characteristic shape of a graph representing exponential population growth, where the population increases rapidly without apparent limits.
Example:
When a new invasive species is introduced to an ecosystem with no natural predators, its population often follows a J-Curve initially.
Logistic growth
Population growth that starts exponentially but then slows down as it approaches the carrying capacity, resulting in an S-shaped curve.
Example:
The population of fish in a newly stocked pond will likely show logistic growth, increasing rapidly at first, then leveling off as food becomes scarcer.
Overshoot
When a population temporarily exceeds the carrying capacity of its environment, often leading to resource depletion and a subsequent population crash.
Example:
If a herd of elk consumes too much vegetation in a short period, they might overshoot their habitat's carrying capacity, leading to starvation.
Population crash
A rapid and significant decline in a population's size, often occurring after an overshoot of the carrying capacity due to resource depletion or increased mortality.
Example:
Following a severe drought that decimated their food supply, a local rabbit population experienced a dramatic population crash.
Population growth
The change in the number of individuals in a population over time, influenced by environmental factors and a species' ability to sustain itself.
Example:
After a successful breeding season, a local bird sanctuary observed a significant population growth in its resident duck species.
S-Curve
The characteristic shape of a graph representing logistic population growth, showing an initial rapid increase followed by a leveling off as the population reaches carrying capacity.
Example:
A graph tracking the growth of a yeast culture in a sealed container will typically display an S-Curve as nutrients become depleted.
Self-Sufficiency
The ability of a species or population to provide for its own needs without external assistance, contributing to its sustainability.
Example:
A highly adaptable species that can find food and shelter in diverse conditions demonstrates strong self-sufficiency.
Unlimited Resources
A theoretical condition where a population has access to an endless supply of all necessary resources, allowing for unchecked growth.
Example:
For a short period, a small group of deer introduced to a vast, untouched forest might experience conditions of nearly unlimited resources.