Download APES Lesson 28 - Levels of Ecological Organization

AP Environmental
Science
Mr. Grant
Lesson 28
Evolution, Biodiversity, and
Population Ecology
Levels of Ecological
Organization
© 2011 Pearson Education, Inc.
Objectives:
• Define the terms ecosystems and niche.
• List the levels of ecological organization.
© 2011 Pearson Education, Inc.
Define the terms ecosystems and niche.
Ecosystems: All organisms and nonliving entities that
occur and interact in a particular area at the same time.
Niche: The functional role of a species in a community.
© 2011 Pearson Education, Inc.
List the levels of ecological organization.
• Ecologists study phenomena on the organismal, population,
community, and ecosystem levels-and, increasingly, at the level
of the biosphere.
• Habitat, niche, and specialization are important ecological
concepts.
© 2011 Pearson Education, Inc.
Ecology is studied at several levels
• Ecology and evolution are
tightly intertwined
• Biosphere = the total living
things on Earth
- And the areas they inhabit
• Community = interacting
species living in the same
area
• Ecosystem = communities
and the nonliving material
and forces they interact with
© 2011 Pearson Education, Inc.
Levels of ecological studies
• Population ecology = investigates the dynamics of
population change
- The factors affecting the distribution and abundance of
members of a population
- Why some populations increase and others decrease
• Community ecology = focuses on patterns of species
diversity and interactions
• Ecosystem ecology = studies living and nonliving
components of systems to reveal patterns
- Nutrient and energy flows
© 2011 Pearson Education, Inc.
Each organism has habitat needs
• Habitat = the environment where an organism lives
- It includes living and nonliving elements
• Habitat use = each organism thrives in certain
habitats, but not in others
- Results in nonrandom patterns of use
• Habitat selection = the process by which organisms
actively select habitats in which to live
- Availability and quality of habitat are crucial to an
organism’s well-being
- Human developments conflict with this process
© 2011 Pearson Education, Inc.
A specialized frog
• Epiphytes grow on trees for support
- Obtaining water from the air
- They collect pools of rainwater and pockets of leaf
litter
- Frogs lay their eggs in
these rainwater pools
© 2011 Pearson Education, Inc.
Habitats vary
• Habitats vary with the body size and needs of species
- A soil mite vs. an elephant
• Species have different habitat needs at different times
- Migratory birds use different habitats during
migration, summer and winter
• Species use different criteria to select habitat
- Soil, topography, vegetation, other species
- Water temperature, salinity, prey
• Species survival depends on having suitable habitat
© 2011 Pearson Education, Inc.
Organismal ecology: niche
• Niche = an organism’s use of resources
- Along with its functional role in a community
- Habitat use, food selection, role in energy and
nutrient flow, interactions with other individuals
• Specialists = have narrow niches and specific needs
- Extremely good at what they do
- But vulnerable when conditions change
• Generalists = species with broad niches
- They use a wide array of habitats and resources
- They can live in many different places
© 2011 Pearson Education, Inc.