Ecology Presentation - Honors
Transcript of Ecology Presentation - Honors
We share the Earth…
Ecology & Environmental Issues
with a whole lot of other creatures…
We don’t share very well….
Ecology Putting it all together…
study of interactions between creatures & their environment, because…
Everything is connectedto everything else
Ecosystem Living (Biotic) factors
all plants & animals living in an area
Physical (Abiotic) factors soil, rock, temperature, moisture,
sunlight
habitat = address (where you live)niche = job (the role you play)
Creatures living in their environment
Populations
Earth’s land ecosystems
Marine
intertidal= lots of nutrients
coral reef= lots of light
benthos= deep ocean
high biodiversity
Tropical rainforest
lots of rain, lots of sunlight, always warm
many plants & animals
high biodiversity
Savannadry season/wet season, always warm
frequent fires in dry season
many herbivores
mid biodiversity
Desert
very dry, hot in day & cold at night
very few plants & only small animals:reptiles, insects, rodents, birds
low biodiversity
Temperate Grassland (Midwest U.S.)
dry season/wet season, cold winters/hot summers
frequent fires in dry season
many herbivores
mid biodiversity
Temperate Deciduous Forest
4 seasons: warm summer with rains, cold winter with snow
deciduous trees, many mammals, insects, birds, etc.
high biodiversity
Coniferous Forest (Taiga)
northern forest, drier, cooler
evergreens, mammals, birds, insects, etc.
mid biodiversity
Tundra
cold year round, dry, permafrost
only lichens & mosses & mostly migrating animals
low biodiversity
How do organisms live together? Community
populations of different species that live in the same place
Feeding relationships
Community
Community Interactions Niche Competition Predation Symbiosis
Mutualism Commensalism Parasitism
Feeding relationships all food chains
start with energy from the sun
first level of all food chains is plants
most food chainsusually go up only 4 or 5 levels
all levels connect to decomposers
Food chains
Fungi
Level 4
Level 3
Level 2
Level 1
Decomposers
Producer
Primary consumer
Secondary consumer
Tertiary consumer
Topcarnivore
Carnivore
Herbivore
Sun
Bacteria
Loss of energy Loss of energy between levels of food chain
To where is the energy lost? The cost of living!
only this energymoves on to the
next level in the food chain
17%growth
50%waste (feces)
33%cellularrespiration
energy lost todaily living
energy lost todaily living
Feeding levels How much energy
can you get from food? only the energy that is
stored in the organism
80-90% energy lost from one level to next
food chain can only have 4 or 5 levels
Food webs
Food chains are linked together into food webs
Who eats whom? eating meat? eating plants?
Many connections throughout ecosystem
Energy flows through…
sun
secondary consumers(carnivores)
primary consumers(herbivores)
producers (plants)
loss of energy
loss of energy
loss of energy
Food chain pyramid Loss of energy between levels of food chain
can feed fewer animals in each level
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Numbers
Vegetarians or Meat-eaters?? How many people can Earth support?
If we are meat eaters? If we are vegetarian?
more people canlive on Earth
fewer people canlive on Earth
But what about nutrients? Energy flows through
but nutrients cycle nutrients must be
recycled to be available for the next generation
decomposers return nutrients to the soil after creatures die fungi bacteria
nutrients
decomposers
Nutrients cycle around… through decomposers
soil
producers
consumers
decomposers
potassium
nitrogen
iron
calcium
phosphorus
magnesium
carbon
2006-2007
loss of energy
loss of energy
sun
secondary consumers(carnivores)
primary consumers(herbivores)
loss of energy producers (plants)
decomposers
Nutrients cycleEnergy flows
soilsoil
biosphere
Ecosystem inputs
constant inputof energy
energy flowsthrough
nutrients cycle
nutrients can only
cycle
inputs energy nutrients
Don’t forgetthe laws of
Physics!
Matter cannotbe created or
destroyed
Beneficial Bacteria 99% of bacteria are HELPFUL not
harmful! Roles they play in the environment
Decomposer Producer Nitrogen fixation Digestion – an example of mutualism
too!!
Characteristics of Populations1. Geographic distribution
– area inhabited by a population2. Density –
-number of individuals per unit area. 3. Population growth – populations can increase or decrease in size based on 3 factors:
Number of Births Number of Deaths Individuals that enter (immigration) or leave
(emigration) a population
Exponential Growth Individuals in a population reproduce
at a constant rate Graph = J-shaped curve At first, growth is slow. Over time,
growth grows until it reaches an infinitely large size.
Occurs under ideal conditions
Logistic Growth As resources become less available,
the growth of a population slows Graph = S shaped When does this happen?
birth rate slowsdeath rate increasesimmigration decreasesemigration increases
Carrying capacity – the largest number of individuals that a given environment can support.
Limiting Factors A factor that causes population
growth to decrease 2 Types
density dependent density independent
Density Dependent Factors Factor that depends on population size Effect large populations the most
Competition – crowded organisms compete with one another for food, water, space, sunlight & other essentials.
Predation – one organism captures & feeds on another organism
Parasitism & Disease – symbiotic relationship in which one organism lives in or on another organism (the host) and consequently harms it (often causing disease or death)
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Moose Wolves
Density Independent Factors Affect all populations in similar ways,
regardless of size Unusual weather Natural disasters Seasonal cycles Some human activities
Species will often crash due to one or more of these factors. After the crash some species will recover to build up again, others remain small.
Succession Primary Succession
No pre-existing community Secondary Succession
Disruption of pre-existing community Climax community
Fully mature ecosystem Equilibrium
Any Questions??