What is Ecology? Flashcards
Lecture 2: Jan. 24
What is Ecology?
The study of the distribution and abundance of organisms and the relationship of organisms to each other and the physical environment.
What questions does ecology address?
Where do organisms occur?
How many organisms occur there?
Why do organisms occur where they do?
What makes up ecological systems?
Individuals, populations, communities, ecosystems, landscapes, the biosphere.
Describe individuals in an ecological system. (Autecology)
Singular organism. Must acquire resources and get rid of waste.
What do individuals affect?
- Conditions of the environment
- Resources available to other organisms
- Flow of energy and chemical elements through the environment
What are adaptations? How do they come about?
How an individual’s morphology, physiology, and behavior allow it to survive in a particular environment.
Come about under natural selection.
Ecosystems are often dynamic steady state systems. What does this mean?
Gains = losses in the ecological system.
(E in = E out).
This allows ecological systems to persist (be stable).
Describe populations in ecological systems.
A group of individuals of the same species living in the same area (geographically or politically).
What five unique properties do populations have that individuals lack?
- Geographic range
- Abundance
- Density
- Change in numbers
- Change in composition (ex. age distribution, sex ratio).
What drives changes in population number and density?
Births, deaths, immigrants, emigrants.
These changes are influenced by species interactions, abiotic factors, genetic mutations, birth defects/rates.
Describe communities in ecological systems.
All populations in a particular area. Boundaries are often artificial and can encompass a large or small area.
What drives diversity and abundance of different species in a community?
Species interactions (interspecific competition, resource-consumer interactions).
Describe ecosystems
One or more communities interacting with their physical/chemical environment (ex. water, air, temp., sunlight).
Non-distinct boundaries.
What is the focus on for ecosystems? What does this encompass?
The flow of energy and cycling of matter between physical and biological components.
Flow of E: E (mostly sunlight) -> O compounds (photosynthesis) -> consumed by herbivores, then predators/parasites. What is not consumed/assimilated (used for growth/repro by consumer) is lost as heat and radiated back into space.
Matter: ex. elements cycle between physical things (atmos., soil, water, etc.) and living organisms.
Describe landscapes in ecological systems.
Multiple ecosystems connected by movement of individuals, populations, matter, and energy.
May include aquatic/terrestrial, natural/disturbed habitats.
Describe the biosphere in ecological systems?
Includes all ecosystems and landscapes on Earth.
Includes wind and water currents, migrating organisms moving energy and nutrients (matter), etc.
Where does energy come from? Where does it go?
The sun.
A trivial amount from chemosynthesis.
Lost to space.
What are producers?
Autotrophs. Convert solar E (photosynthesis) or chemical energy (chemosynthesis) into organic compounds.
Done by most algae and plants, many bacteria.
What are consumers?
Heterotrophs. Obtain E from other organisms (herbivores, predators, parasites, parasitoids, scavengers, detritivores, decomposers).
How do mixotrophs obtain energy?
From photosynthesis AND consumption of organic carbon/other organisms (ex. many algae, carnivorous plants).
What role do herbivores play?
Consume primary producers (plants). Typically do not kill the plant so are considered plant parasites.
What role do predators play?
Kill and consume multiple prey (herbivores, other predators, etc.) to complete development and sustain oneself.
What role do parasites play?
Live in/on the body of another organism. Only one host required to complete development; parasite rarely kills host.
What role do parasitoids play?
Similar to parasites: develop in/on host organism.
Similar to predator: always kill their host.
Mostly wasps and flies.
What role do scavengers/detritivores/decomposers play?
Consume dead organic matter (recycle it back through the ecosystem).
Scavengers: consume dead animals
Detritivores: break down organic matter into smaller particles
Decomposers: Break down organic material into simpler compounds and elements.
What are types of interspecific interactions?
- Competition
- Mutualism
- Commensalism
- Symbiosis
What is the outcome of competition?
Has negative effects on two species that require the same resource to survive/grow/reproduce.
What is the outcome of mutualism?
Two species are benefitted due to their interaction with each other.
What is the outcome of commensalism?
One species benefits while the other is neither helped nor harmed.
What is symbiosis?
Any physically close relationship between two organisms, whether helpful or harmful.
