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Environmental Changes
Ecological SuccessionThe natural process where a
habitat changes over time
Succession
• Bedrock- lichens- mosses- grass- trees
and shrubs- forest
• Gradual changes result in a stable
community
• Climate changes, natural disasters, animal
plant and human activity can alter the
stable environment
• Example: lake to forest- lake-sedimentsplant debris build up- lake fills in- swampforest
Succession
Lake Succession
Relationships
Symbiosis- organisms live
together
Symbiotic Relationships
• Commensalism- one organism benefits
and the other is not benefited or harmed.
EX. Barnacle on whale
• Mutualism- both organisms benefit
EX. Nitrogen fixing bacteria- fix nitrogen
for use by plants, protozoa in termites
• Parasitism- one organism benefits, the
other is harmed EX. Tapeworm or fleas in
dogs
The anemonefish lives
among the forest of
tentacles of an anemone
and is protected from
potential predators not
immune to the sting of the
anemone. The anemonefish
is protected from the sting
of the anomone tentacles
by a substance contained
in the mucous on its skin.
The exact nature of this
protective substance is not
known, but is believed to
be a combination of a
partial natural secretion
and chemicals the fish
harvests by rubbing up
against the anemone's
tentacles. What ever the
case may be, the anemone
treats the fish as part of
itself and does not sting it.
Commensalism
Mutualism
Bees and many
species of flowering
plants interact with
each other in a
mutualistic fashion. In
this interaction, the
flower becomes
pollinated by the
insect, while the bee
receives food in the
form of pollen and
nectar.
Parasitism
Mosquito: Females
ingest blood for the
protein. Male
mosquitos ingest
plant juices.
Very few animals have a diet that is restricted only a single food source, so the
concept of a linear food chain is extremely simplistic. In reality, trophic relationships
within a community are more like a food web in which dozens of plant species
support a wide variety of herbivores which in turn are consumed by numerous
predators and parasites. If one species within a food chain becomes scarce
(perhaps due to bad weather or over-exploitation), there will be serious
repercussions on all other species in the chain. But in a complex food web,
changes in individual populations are likely to have a smaller impact because they
are buffered by the availability of an alternative prey or host species.
Material Cycles
The recycling of Oxygen, Carbon
Dioxide, and Hydrogen in an
ecosystem from living organisms to soil
and back to living organisms
Cycles
• Photosynthesis- O2- Respiration- CO2photosynthesis
• Water- evaporation- water- condensation
• Nitrogen in air- converted to nitrates in soil
for use by plants by nitrogen fixing
bacteria
• Nitrates in soil converted to protein by
plants
• Nitrogenous waste and dead organisms
release ammonia when decomposed
Nitrogen cycle
Oxygen/Carbon Dioxide
Water Cycle