Presentation on theme: "Forests and their Interactions AP Environmental Science."— Presentation transcript:
Forests and their Interactions AP Environmental Science
Types of Forests Any area where trees cover more than 10% of land. Includes: a. open savannas - < 20% ground cover b. 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 them ecologically significant.
Types of Forests-Old Growth Other names include: 1. Virgin forests 2. Primary forests 3. Ancient forests 4. 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!! EErosion WWater Runoff EExcess CO2 LLoss of biodiversity LLoss of cultural & historic values
Forest Fires Forest Fire Management Forest Fire Management Nova Fires by Month 2000 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 Legislation 1. Debt for Nature Swap 2. Roadless Rule – Clinton Administration 3. Northwest Forest Plan to regulate harvesting on about 9.9 million ha of federal lands in Oregon, Washing and northern California.
Question to ponder? TThe largest area of old-growth forest in the United States is located in: A. Alaska B. B. Montana C. California D. North Carolina E. 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 i nterspecific 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. distichus A. aliniger A. distichus A. cybotes A. ricordii A. insolitus A. christophei A. etheridgei A. christophei A. etheridgei A. 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 species 2. Evolution of one species to use a different set of resources Resource 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!)
REPRODUCTIVE POTENTIAL COMPARISON 1. R-selected Hint: Rapid Repro a. Early reproduction b. Short life span c. Hi mortality d. Little/no parental care e. Large # of offspring produced 2. K-selected Hint: Longer Repro a. Late reproduction b. Long life span c. Low mortality d. High parental care e. Small # of offspring produced
REPRODUCTION TYPES K-SELECTED TYPE R-SELECTED TYPES
Reproduction Connection Which of the following is generally true of a K-strategis t 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 Wounding Detection by plant Release of volatile attractants Recruitment Chemical in saliva