The Ecology of Organisms and Populations. Ecology is the interaction between organisms and their environments. Environment can be divided into two parts: biotic and abiotic. Abiotic is nonliving Chemical and physical factors Temperature Light Air Water Minerals Fire Wind.
Ecology is the interaction between organisms and their environments.
Abiotic is nonliving
thick do you think the Biosphere would be?
Tundra and Prairie deserts
Chaparral and Savanna
Rich soils (lots of organic matter decay)
Many different types of trees
Trees loose leaves in cycles
(fall and spring mainly)
Rain (tropical) forest deserts
-up to 300+ inches of rain per year
-large trees-100’s of feet tall
-largest diversity of organisms of any biome
-divided into two parts; upper canopy above the
tree tops and forest floor
-trees will lose leaves during
Intertidal Benthic Estuary Pelagic
In Estuary Pelagic undisturbed ecosystems, all organisms keep each
other in check. Even the top predators control each
Ecosystems are complicated networks of trophic
--the pattern of feeding levels that determines
energy flow and chemical cycling in an ecosystem.
Tropic levels include:
Autotrophs—plants and plant material
the producers in an ecosystem
photosynthetic, so they can produce their
Heterotrophs– organisms that depend on other
organisms to feed them.
Heterotrophs are broken down into three categories: Estuary Pelagic
Herbivores—eat only plant material and have wide
flat teeth adapted for grinding down the plants
Omnivores – eat both plant and animal material
and have both flat teeth for grinding and canine
teeth for tearing.
Carnivores – eat only (mainly??) meat and have
canine teeth allowing them to grasp and tear flesh
Detrivores decompose organic matter and speed
up the process of returning nutrients to soil.
Most bacteria act as detrivores.
When wolves were exterminated from the West in the Estuary Pelagic
1920’s many shifts occurred in the food chain:
Elk numbers multiply…their #1 predator is gone
Quality of elk declines without predation
Elk eat many young aspen trees…even manage
to completely eliminate some
Without aspen, beaver are left without food
Beaver leaves and no dams are made so some
aquatic life suffers…
All because the wolf was removed from the ecosystem
Ripple effect is felt throughout the food chain.
Return wolf to environment in 1995 and 1996 Estuary Pelagic
wolves from Canada released in YNP (31) and central Idaho (35)
current numbers as of Dec. 2008 from USFWS data (GYA-449) (CID-803)
Subsequent increase in number of young aspen trees Estuary Pelagic
Elk can’t “hang out” here anymore because they
block the view and cannot see predators
Wolves prey on old and sick elk…reduce overall #’s
Beaver returns because food supply is increased Estuary Pelagic
Beaver dams create new aquatic environments thus inviting new aquatic life…i.e. Boreal toads
Balance is restored to
Do humans cull animals from populations like Natural Selection does?
--what type of animal do humans hunt??
--what does mother nature cull out??