forests and their interactions
DESCRIPTION
Forests and their Interactions. AP Environmental Science. Types of Forests. Any area where trees cover more than 10% of land. Includes: open savannas - < 20% ground cover Closed canopy forest – tree crowns overlap to cover most of the ground. - PowerPoint PPT PresentationTRANSCRIPT
Forests and their InteractionsAP Environmental Science
Types of Forests Any area where trees cover more than
10% of land. Includes:a. open savannas - < 20% ground coverb. Closed canopy forest – tree crowns
overlap to cover most of the ground.c. Primary forests: composed primarily of
native species
Reason why old forests are important?O.F. contain unique biological features w/: large live & dead trees a large variety of vegetation, insects
and animals species. Often home to rare species, threatened
species and endangered species of plants and animals, making themecologically significant.
Types of Forests-Old Growth
Other names include: 1. Virgin forests2. Primary forests3. Ancient forests4. Primevil forests
Old Growth Forests
New Growth Forests
New Growth forests
Deforestation & Consequences
Cause of deforestation? Logging industry Cattle ranching Farming Biofuel production Food production
(ie. palm oil)
Consequences!! Erosion Water Runoff Excess CO2 Loss of
biodiversity Loss of cultural &
historic values
Forest Canopies Upper canopy Mid-canopy Lower Canopy http://www.canopyintheclouds.com/pano
s/elfinforest
Forest Fires Forest Fire Management Nova Fires by Month 2000
Forest Fires-Hot Question In Mediterranean climates like portions of
California, a wetter than normal winter often leads to greater severity of fires following summer. This paradox occurs because increased rain leads to…
A. Greater accumulation of chaparral biomass B. Higher pollination of annual flowers C. Greater recreational use of parklands D. Greater erosion & damage to access roads E. Decreased summer rainfall
Forest Protection Legislation1. Debt for Nature Swap2. Roadless Rule – Clinton Administration3. Northwest Forest Plan to regulate
harvesting on about 9.9 million ha of federal lands in Oregon, Washing and northern California.
Question to ponder? The largest area of old-growth forest in
the United States is located in:A. AlaskaB. B. MontanaC. CaliforniaD. North CarolinaE. Michigan
Forest and Competition There are several species interactions
within an ecosystem:
1. Competitive Exclusion Principle 2. Resource Partitioning 3. Ecological Niche
This type of interspecific competition:– may occur when 2 or more species in community
use similar resources & those resources are in short supply OR
- may limit the population growth of the competing species
Intraspecific Interactions– Relationships within the same species
Competition Between Species
Experiment #1: Russian ecologist G. F. Gause studied the effects of interspecific competition in two closely related species of protists called Paramecium.What do these results tell you about the interaction of these 2 species?
1.
1. Competitive Exclusion Principle
P. aurelia
P. caudatum
Separate cultures
Combined cultures
From his research, Gause concluded that two species so similar that they compete for the same limiting resources cannot coexist in the same place for any length of time.
One species will always be more efficient and adaptable:….in getting food….in reproducing
• Ecologists called this concept the competitive exclusion principle
Ecological Niche:a. Sum total of a species’ use of biotic and abiotic resources in its environ &
b. A species’ habitat & it’s job (ex. Forest / producer)
• We can now restate the competitive exclusion principle as follows:
Two species cannot coexist in a community if their niches are identical.
Figure 19.7
A. ricordii
A. distichusA. aliniger
A. distichusA. cybotes
A. ricordii
A. insolitus
A. christophei
A. etheridgei
A. christophei
A. etheridgeiA. cybotes
A. distichus
A. insolitus
Resource Partitioning-
Experiment #1: Explain this example of resource partitioning. How have the different species adapted to their competition?
A. insolitus
There are two possible outcomes of competing species w/ identical niches (not just living in the same area)
2. Resource Partitioning
1. Extinction of one species2. Evolution of one species to use a
different set of resourcesResource partitioning is the differentiation of niches that enables similar species to coexist in a community.
Reproductive Potential…Is an organism’s ability to grow at the fastest rate.
(To replenish the species—innate!)
REPRODUCTIVEPOTENTIAL COMPARISON
1. R-selectedHint: Rapid Reproa. Early
reproductionb. Short life spanc. Hi mortalityd. Little/no
parental caree. Large # of
offspring produced
2. K-selected Hint: Longer Reproa. Late
reproductionb. Long life spanc. Low mortalityd. High parental
caree. Small # of
offspring produced
REPRODUCTION TYPESK-SELECTED TYPE
R-SELECTED TYPES
Reproduction Connection Which of the following is generally
true of a K-strategist species? A. They reach sexual maturity faster. B. They have more young. C. They are likely to be invasive
species. D. They have longer life spans. E. Their populations cycles are more
rapid.
The interrelatedness of interactions between species makes communities complex
The Complexity of Community Networks
Figure 19.17
WoundingDetection by plant
Release of volatile attractants
Recruitment
Chemical in saliva