Overview of Ecology
Ecology is a way of looking at organisms and their surroundings, which is often called
an ecosystem (in the big picture, the biosphere). Ecology is the field of biology
that looks at our environment and what goes on in our surroundings.
When we study ecology we ask questions and make observations about our surroundings.
For example, we might ask why certain organisms live where they do? We can see
that:
- Different organisms are found in different places
- There are only a few basic types of communities, or biomes, on earth which extend
over large land masses, (although, as one might suspect, most of these grade into
each other)
Ecological studies try to find out what characteristics the organisms have which give
them an advantage in their surroundings, and to find out what are the critical factors
of that ecosystem that help determine the successful characteristics.
So in the study of ecology we look at the:
Structure of ecosystems (what's there)
Processes occurring in ecosystems
Community Interactions
Biomes: the types of Ecosystems and the characteristic climatic features and organisms
that inhabit specific biomes
Your textbook provides an overview of some basic processes in ecology.
We will discuss some of the physical and biological interactions of ecosystems in
class, concluding with the terrestrial biomes, the different broad ecosystems we
find on earth. An outline of topics traditionally included in ecology follows. We will
address many of these in our remaining class time this term.
Abiotic (Non-living) Components of Ecosystems
Climate
- Solar radiation
- Air circulation (wind patterns)
- Light
- Heat (temperature)
- Atmosphere
- Substrate (mostly soils)
Dynamics of Ecosystems (Both Biotic and Abiotic Components)
Energy Flow in Ecosystems
- Trophic Levels (Who eats Whom?)
- Sun
- Producers
- Consumers
- Herbivores
- Carnivores (1 , 2 , 3 etc.)
- Reducers (Decomposers)
- Energy Flow Patterns
- Pyramids
- Energy pyramids
- Number pyramids
- Biomass pyramids
- Usefulness of one pyramid level biomass to next level
- Efficiency of obtaining energy source
- Ratio of nutrients to food volume
- Metabolic rates of consumers/reducers
- Trophic Levels, Complexity and Food Webs
Nutrient Cycles
- Energy used by living organisms is chemical
energy so major process of ecosystem is movement of nutrients
- Some nutrient cycles
- Human impacts on nutrient cycles
- Modifying amounts, form and location of nutrients
Community Interactions (Population Regulations) (Adjusting to the Carrying Capacity)
- Interactions that help to maintain populations at carrying capacity
- Competition
- Predation
- Plant-herbivore
- Predator-prey
- Mutualisms
- Commensalisms
We tie characteristics of the environment together when we look at Biomes
(and the Aquatic Life Zones for aquatic ecosystems which are not included
in your text or in this class). For biomes we look at features of climate,
characteristic vegetation, typical consumers, special needs (adaptations)
for survival, and human impacts on the biome.
Types of Terrestrial Biomes
- Tundra
- Coniferous Forest (Taiga)
- Temperate deciduous Forest
- Deserts
- Scrub or Mediterranean Forest
- Grasslands
- Savanna
- Tropical Forests
- Rain or Evergreen
- Deciduous
- Other Forests
Aquatic Life Zones
(Ecosystems)
- Lake Ecosystems
- Lake zones
- Seasonal lake changes
- Nutrient nature of lakes
- Marine Ecosystems
- Types
- Estuaries
- Coastal
- Open ocean