Environments of Life: Some Concepts
a. Habitat: Setting on or close to the Earth’s surface that are inhabited
1. Marine (oceans and seas) Reefs
2. Freshwater (lakes, rivers, and streams)
b. Ecology: the study of the factors that govern the distribution and abundance
of organisms in natural environments
c. Niche: relations between a given species and it environment
d. Life Habitat: the way a species lives within its niche.
i. Limiting factors: physical and chemical conditions that restrict every
species to its niche.
e. Population: group of individuals that belong to a single species
f. Community: populations of several species living together in a habit.
Some species feed on others
i. Producers: the foundation of the system, photosynthesizing organisms
or bacteria that harness the energy of chemical reactions
ii. Consumers: herbivores which feed on producers
iii. Carnivores, feed on other consumers
g. Ecosystem: Organisms of an ecological community and the physical environment
they occupy. Come in all sizes
i. Fauna: The animals and protozoans (Protists) of an ecosystem
ii. Flora: Plants and plantlike Protists of an ecosystem
iii. Biota: Flora and fauna living together
iv. Food Chain: sequence of species from producer to top carnivore
v. Diversity: designate the number of species that live together within
vi. Opportunistic species: species that specialize in invading newly vacated
habitats, e.g, land cleared by fire, or shore areas formed along rivers
that change course at flood stage.
h. Biogeography: Distributions and abundances of organisms on a broad geographic
i. Realms: a primary marine or terrestrial biogeographic division of the
a. Plankton: organisms that drift in water
b. Nekton: Animals that move through the water primarily by swimming
c. Pelagic: plankton and nekton in the open ocean
d. Benthos: immobile and mobile organisms that populate the seafloor.
e. Benthic herbivores graze on plantlike forms like algae
i. Suspension feeders: strain phytoplankton and plan debris from the water.
ii. Deposit feeders: Consume sediment and digest organic mater mixed in
with mineral grains.