Download Ecology primer EE

Ecosystems
Producers
• Producers – autotrophs
• Make their own food
– Photosyntheis
– chemosynthesis
Consumers
• Heterotrophs obtain their food by feeding
on other organisms
– Herbivores – eat plants
– Carnivores – eat meat
– Omnivores – eat plants
and animals
Decomposers
• Consumers that release nutrients in the
process of obtaining nutrients
• Detritivores – feed on wastes or decaying
bodies of other organisms
Food chain/food web
• Sequence of organisms each acting as a
nutrient for the next organism
• Complex network of interconnected food
chains
Ecology
• How organisms interact with one another
• Five levels:
– Organisms – an individual being
– Populations-a group of individuals of the same species
– Communities-populations of different species living in a
particular area
– Ecosystems-a community interacting with one another
and their nonliving environment
– Biosphere-parts of earth where life is found
Evolution
• Process whereby earth’s life changes over
time through changes in the genetic
characteristics of populations
– Begins with a mutation (change in DNA) that
results in a new genetic trait
– Natural selection-environmental conditions
favor some individuals with certain traits that
give them an advantage enabling them to
survive and reproduce at a higher rate
Adapted to cold through
heavier fur, short ears,
short legs, and short
nose. White fur matches
snow for camouflage.
Arctic Fox
Northern
population
Early fox
population
Different environmental
conditions lead to different
selective pressures and
evolution into two different
species.
Spreads
northward and
southward and
separates
Gray Fox
Southern
population
Adapted to heat through
lightweight fur and long
ears, legs, and nose,
which give off more heat.
Fig. 4-10, p. 91
Niche
• A species’ way of life in a community and
includes everything that affects its survival
and reproduction
– How much water and sunlight it needs how
much space it requires
– What it feeds on and what feeds on it
Fig. 4-14, p. 96
Species Interact in Five Major Ways
• Interspecific Competition-species compete for resources
• Predation-predator feeds on all or part of the prey as part of a
food web
• Parasitism-one species feeds on or inside the host; host is often
harmed
• Mutualism-two species behave in such a way that both benefit
• Commensalism
Interspecific Competition
• Competition for limited resources
• One species becomes more efficient than
another species
• When 2 species compete their niches
overlap
• Greater overlap – more intense
competition
One species takes the larger
share of resources
• Competing species must:
1. Move to another area
2. Adapt by shifting feeding habits/behavior
through natural selection to alter its
niche
3. Suffer population decline
4. Become extinct
What is biodiversity?
The variety of species and the genetic variety within a species
Abiotic factors – the
nonliving parts of an
ecosystem
sunlight
water
Rocks and soil
Biotic factors - the living parts
of an ecosystem
Plants, animals and
microorganisms
Identify biotic and abiotic
factors in each picture.
biome
• Large regions with distinctive climates and
organisms (especially vegetation) adapted
to them
Biomes of the 39th parallel of the US
Threats to biodiversity
•
•
•
•
•
•
H – habitat destruction
I – invasive species
P – population growth
P – pollution
C – climate change
O - overexploitation
Native versus nonnative
• A native species is a species that normally
lives in and thrives in an ecosystem.
• A nonnative species is a species that
migrates into or is introduced into an
ecosystem (also referred to as exotic
species)
• Invasive species are species that are
nonnative and harmful to their new
ecosystem (invasive because they have
no natural predators or competition to
control their numbers)
Invasive species
• Kudzu – brought from Japan to control
erosion
• Zebra mussels – clog water lines –
brought in accidentally on ships
• Fire ants
• nutria