Ecosystems glossary Flashcards
(28 cards)
What is biodiversity?
A collective term used to describe the vast multitude of life on Earth, relating to all living things including plants, animals, and bacteria.
A measure of the variety of life, usually referring to the number of species in an area, but includes both species richness and species abundance.
What is biomass?
A measure of the mass of every living organism, measured in tonnes of carbon.
What is vulnerability in an ecosystem?
The ease with which an ecosystem can be changed.
What is resilience in an ecosystem?
The ecosystem’s ability to deal with change.
What is dynamic equilibrium?
Refers to the state within an ecosystem where population, energy flow, and nutrient cycles tend to remain stable over time, even with changes.
When vulnerability is equal to resilience, the ecosystem can be characterized as being in a state of dynamic equilibrium.
What is an ecosystem?
Systems through which incoming solar energy is captured and channeled through a hierarchy of life forms.
What is ecosystem functioning?
The combined effects of all natural processes that sustain an ecosystem.
What is energy flow?
The flow of energy through living things within an ecosystem.
What are natural systems?
Open systems whose elements, boundary, and relationships exist independently of human control.
What is the nutrient cycle?
The repeated pathway of particular nutrients or elements from the environment through one or more organisms back to the environment.
What is ecological stress?
Natural factors that can cause disruption to ecosystems.
What is human stress?
Activities and impacts on ecosystems that are directly caused by human actions, e.g., habitat destruction.
What is ecological integrity?
Exists when an ecosystem is whole and unaltered by human activity.
In reality, it is impossible to find an ecosystem with no human influence.
What is biocapacity?
Relates to the regenerative capacity of an ecosystem - the ability of the ecosystem to replace resources used by humans and absorb pollutants emitted by human activities.
The higher the biocapacity, the more resilient it is to stresses caused by humans.
What is a feedback loop?
The result of a causal relationship between 2+ processes in nature.
Results from one process giving rise to another, which then causes the original process to accelerate or diminish.
What is elasticity in an ecosystem?
The rate of recovery of an ecosystem property following disturbance.
What is amplitude in an ecosystem?
Refers to the threshold level of strain beyond which return to the original state no longer occurs.
What is malleability in an ecosystem?
The difference between the ecosystem’s final recovery level and pre-stress level.
The greater the difference, the less resilient the ecosystem.
What is a tipping point?
A situation where even small changes can cause profound changes.
Biome
Region of world characterised by its resident life, environment and climate. Temperature, precipitation and amount of sunlight are key factors that define each biome.
Examples: savanna, rainforest, desert.
Ecosystem
A community of organisms and their physical environment interacting together.
Encompasses both abiotic and biotic factors (living and non-living facto
Habitat
Specific to a species or population of organisms
Species
Each species is a group of organisms with unique characteristics. An individual of a species can reproduce successfully, creating viable offspring, only with another member of that species.
Foundation species
The “engineers of ecosystems.” The activities of foundation species physically modify the environment and produce and maintain habitats that benefit other organisms that use those habitats. The North American beaver is the classic example of a foundation species. Beavers harvest trees, thus removing undergrowth and maintaining an open forest understory.Harvested trees are used to build dams, which retain stream water to form a pond, providing suitable habitat for a variety of aquatic organisms and a water source for terrestrial organisms.
