Ecosystems
Relationships and Populations
Biotic Factors
ECOSYSTEM
Abiotic Factors
Biotic and Abiotic Factors
(Living and Non-Living)
NichePart of the environment that
an organism uses
ROLE + HABITAT
Bay-Breasted WarblerFeeds in the middlepart of the tree
Yellow-Rumped WarblerFeeds in the lower part of the tree andat the bases of the middle branches
Cape May WarblerFeeds at the tips of branchesnear the top of the tree
Spruce tree
Warbler Niche
Community interactions
Competition individuals or species trying to use the same limited
resource
Competition competitive exclusion principle – 2 species
cannot occupy the same niche in the same habitat at the same time
Predator/Prey - +/- -the predator catches the prey
- One organism captures and kills another
http://inspectorgadget.files.wordpress.com/2007/12/tiger.jpg
http://www.wallpaperbase.com/wallpapers/animals/tigers/tiger_6.jpg
Two species living closely together
http://sugarmtnfarm.com/blog/uploaded_images/ClownInBubbleAnemone200511-780236.jpg
Symbiosis
Symbiosi
s a.Mutualism - +/+
both species benefit
Symbiosisb. commensalism
- +/0
– one benefits, the other is not helped nor
harmed
Example – a bird’s nest in a tree OR barnacles
on whales
Symbiosi
s c. Parasitism - +/- one species benefits (parasite), one is harmed
(host)
Ecological Succession – natural
progression of an environment 1. primary succession – starting where there is no soil
http://www.v-liz.com/galapagos/isabela/puntam~1/lavacac-.jpg
2. secondary succession – where there was a community, but it has been removed
Climax Community – last stage of succession, ecosystem has reached equilibrium
Important characteristics of populations
•geographic distribution – the area inhabited by a
population•density –
number of individuals per unit area•growth rate –
depends on birth rate and death rate
low density high density
•density – number of individuals per unit area
Exponential growth
ideal conditions
unlimited resources
Growth rate of bacteria
•some bacteria can divide every 20 minutes
•first 20 minutes – there will be two bacteria
•in one hour - there will be 64 bacteria
•in one day – there would be:
4,720, 000,000,000,000,000,000
or 4.72 x 1021
Logistic growth
as resources become limited•growth rate slows or stops•carrying capacity is reached
•Carrying Capacity – maximum population size an area can support
Num
ber
of
Yeast
Cel ls
Time (hours)
Carrying capacity
Logistic Growth – S shaped curve, levels off at the Carrying Capacity
Limiting factors nutrient
space
carbon dioxide level
density-dependent – competition, predation, disease, parasitism
density-independent – weather, human activities, seasonal cycles
Populations are dependent on Predator/Prey Relationships
Age-structure diagram shows number or percentage at each age
Top Related