ecology I and II Flashcards
(36 cards)
Branch of biology which studies interrelationships
in communities and ecosystems
ECOLOGY
members of the same species occupying a common geographic area
population
populations of many species within a common geographic area
communites
The place where an organism can be found (e.g., under rocks, sea cliffs).
habitat
Define “ecological niche.”
The “profession” or role of an organism in a community, including its interactions with the physical environment.
What is competition in ecology?
Occurs when more than one species in an ecosystem have overlapping niches.
Define “ecosystem.”
Communities (biotic) and inorganic (abiotic) environment.
What is a biome?
Regions of the world characterized by a specific main type of ecosystem (e.g., tropical rain forest, tundra).
what is the biosphere
the sum of all the world’s ecosystems
what is a limiting factor
An abiotic component that limits the growth of populations in an ecosystem.
the predictable sequence of plant and animal communities replacing each other until a stable or climax community is established.
succession
Difference between primary and secondary succession?
Primary: succession on bare rock; Secondary: succession after disturbance in an established community.
what is the ultimate energy source for the biosphere?
the sun
What percentage of energy becomes “new organism” (anabolism) after consumption?
10 percent
who are producers?
Green plants, algae, some bacteria that synthesize organic compounds from inorganic ones using sunlight.
who are consumers
Animals that get food by eating other organisms.
insects, fungi, and bacteria that break down dead organic material.
What are decomposers?
what is an energy pyramid
a diagram showing energy stored as biomass at each trophic (feeding) level, with energy decreasing at higher levels.
What is biomagnification?
Accumulation of non-biodegradable compounds in organisms at higher trophic levels
what is a food web
the complex interrelationship of “who eats whom” in an ecosystem.
Why are natural ecosystems stable?
Due to efficient cycling of materials, balanced predation/parasitism, and reproductive capacity.
What is a monoculture?
An agricultural practice where only one type of crop is grown, reducing biodiversity.
How do human activities reduce biodiversity?
By loading ecosystems with waste, removing natural ecosystems, and replacing them with monocultures.
What is the main goal for more “natural” human ecosystems?
To achieve stability by recycling, reducing reliance on fossil fuels, and working in harmony with nature
