Download 1.1 Biotic and Abiotic Factors in Ecosystems (sec 2.1 pg 21-24)

1.1 Biotic and Abiotic Factors in
Ecosystems
(sec 2.1 pg 21-24)
• The study of how organisms interact with each
other and with their physical environment is called
ecology.
• For practical reasons, ecologists divide the
environment into different levels:
• The environment is divided into different levels:
• Level 1: organism = single living thing.
• The environment is divided into different levels:
• Level 2: population = all of the organisms of the
same species that share a habitat.
• The environment is divided into different levels:
• Level 3: community = all of the different
populations in a particular area that interact.
• The environment is divided into different levels:
Level 4: ecosystem = includes the living community
as well as the physical environment in which the
organisms live
• The environment is divided into different levels:
• Level 5: Biosphere = is the total area of Earth where
living things are found.
• Each environment has two kinds of factors:
– Abiotic = non-living factors
– Biotic = living factors
ABIOTIC FACTORS
BIOTIC FACTORS
• A limiting factor is the most critical factor in
determining the types of organisms that exist in an
ecosystem.
• Many organisms compete for the same limiting
factor(s).
• Many ecosystems are in a state of dynamic
equilibrium, where there is a balance between the
abiotic and biotic factors and their connection to
each other, but there is also continuous change.
• Most ecosystems experience continuous change,
but the overall system is still stable.