the principles of ecology. ecology the study of how living things interact with each other and with...
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The Principles of Ecology
Ecology The study of how living things interact
with each other and with their environment By necessity it overlaps with geology,
geography, climatology and other sciences.
An organism is an individual living thing Like every other organism all organisms
have two basic needs ENERGY AND MATTER
Ecology Matter and energy are obtained from
the environment Organisms depend on and are influenced
by their environment Contains two kinds of factors
Biotic – living things Other organisms as well as members of the same
species Abiotic – nonliving aspects
Sunlight, Soil, Temperature, Water
The Ecosystem A unit of nature and the focus of the
study of ecology All the biotic and abiotic factors in an
area and how they interact with each other They vary in size
Lake Dead log
Ecosystems and Energy These are not closed systems
They need inputs of energy Most comes from sunlight A small amount comes from chemical
compounds Matter is not constantly added to an
ecosystem Matter is recycled
Water, Carbon, Nitrogen, Phosphorus
Niche Refers to the role of a species in its
ecosystem Includes the way the species interacts
with the biotic and abiotic factors of the environment.
The niche of a species The food it eats and how the food is
obtained
Bird Niches
Habitat This is the physical environment in
which a species lives and to whit it is adapted Mainly determined by abiotic factors
Temperature and rainfall These factors also influence the traits of the
organisms that live there
Competitive Exclusion Principle
A given habitat may have many different species, but each species must have a different niche.
Two different species cannot occupy the same niche in the same place for very long. This is know as the competitive exclusion
principle They compete for the same food and other
resource found in the environment
Competitive Exclusion Principle
Flow of Energy Energy enters in the form of sunlight or
chemical energy Some organisms use the energy to make
food Other organisms get energy by eating
food
Producers Produce food for themselves and other
organisms They are called autotrophs
Photoautotrophs Plants, Algae, and Bacteria
Chemoautotrophs Some bacteria, archea
Chemoautotrophs
Consumers Depend on other organisms for food
All animals and fungi Many Bacteria Some plants Called Heterotrophs
Herbivores Consume producers
Deer, Rabbits, Mice Carnivores (Obligate carnivores-can’t eat
plants Consume animals
Omnivores Eat both plants and animals
Decomposers Break down the remains and other waste
and release simple inorganic molecules back into the environment Scavengers – consume the soft tissues of
dead animals Vultures, Raccoons, and Blowflies
Detritivores – consume detritus Dead leaves, animal feces, and other organic
debris Earthworms, Millipedes, dung beetles on land Bottom feeders in water like sea cucumbers and
catfish Saprotrophs – feed on what’s left
Fungi, single-celled protozoa
The Ultimate Recyclers http://science.kqed.org/quest/video/scie
nce-on-the-spot-banana-slugs-unpeeled/
Food Chains and Food Webs They Show Who eats Whom Food Chains
Represent a single pathway through which energy and matter flow through an ecosystem
Food chains are generally simpler than what really happens in nature Typically not a one-on-one relationship
Food ChainWhere would you add the decomposers to this picture?
http://www.youtube.com/watch?v=TE6wqG4nb3M
Food Webs Represents multiple pathways through
which energy and matter flow through the ecosystem Includes many intersection food chains Shows that most organisms eat, and are
eaten, by more than one species.
Food Web
Trophic Levels The feeding positions in a food web are
called trophic levels Most food webs have 2-3 trophic levels
with a typical maximum of 4 levels
Trophic LevelsTrophic Level Where it Gets
FoodExample
1st – These are the producers
Make their own food
Plants
2nd Trophic Level – Primary Consumers
Consume Producers
Mice eat plants
3rd Trophic Level – Secondary Consumers
Consume Primary Consumers
Snakes eating mice
4th Trophic Level – Tertiary Consumers
Consumer Secondary Consumers
Hawks eat Mice
Trophic Levels and Energy Only about 10% of the energy from one
level is available for the next level So: What happens to the other 90%
Used for metabolic processes Given off to the environment as heat This is called the 10% rule
Energy Pyramid
Trophic Levels and Biomass
With less energy available to higher trophic levels there tend to be fewer organisms on those levels
Organisms at the higher trophic levels also tend to be larger in size
Biomass is the total mass or organisms at a trophic level
Ecological Pyramid
Summary Ecology is the study of how living things
interact with each other and their environment. The environment include abiotic and biotic factors
An ecosystem consists of all the biotic and abiotic factors. A niche refers to the role of a species in its ecosystem. A habitat is the physical environment in which a species lives and to which it is adapted. Two different species can’t occupy the same niche in the same place for very long.
Summary, Continued Ecosystems require constant inputs of
energy from sunlight and chemicals. Producers use energy and inorganic molecules to make food. Consumers take in food by eating producers or other living things. Decomposers break down dead organisms and other organic wastes and release inorganic molecules back to the environment
Summary Continued One More Time
Food chains and food webs are diagrams that represent feeding relationships. They model how energy and matter move through an ecosystem.
The different feeding positions in a food chain or web are called trophic levels. Generally, there are no more than four trophic levels because energy and biomass decrease from lower to higher levels.
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