Presentation on theme: "Forests and their Interactions"— Presentation transcript:
1 Forests and their Interactions AP Environmental Science
2 Types of Forests Any area where trees cover more than 10% of land. Includes:open savannas - < 20% ground coverClosed canopy forest – tree crowns overlap to cover most of the ground.Primary forests: composed primarily of native species
3 Reason why old forests are important? O.F. contain unique biological features w/:large live & dead treesa 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.
10 Deforestation & Consequences Cause of deforestation?Consequences!!Logging industryCattle ranchingFarmingBiofuel productionFood production (ie. palm oil)ErosionWater RunoffExcess CO2Loss of biodiversityLoss of cultural & historic values
12 Forest FiresForest Fire ManagementNova Fires by Month 2000
13 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 biomassB. Higher pollination of annual flowersC. Greater recreational use of parklandsD. Greater erosion & damage to access roadsE. Decreased summer rainfall
14 Forest Protection Legislation 1. Debt for Nature SwapRoadless Rule – Clinton AdministrationNorthwest Forest Plan to regulate harvesting on about 9.9 million ha of federal lands in Oregon, Washing and northern California.
15 Question to ponder?The largest area of old-growth forest in the United States is located in:AlaskaB. MontanaCaliforniaNorth CarolinaMichigan
18 Forest and Competition There are several species interactions within an ecosystem:1. Competitive Exclusion Principle2. Resource Partitioning3. Ecological Niche
19 Competition Between Species 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 InteractionsRelationships within the same species
20 1. 1. Competitive Exclusion Principle 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?Separate culturesCombined culturesP. aureliaP. caudatum
21 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 reproducingEcologists called this concept thecompetitive exclusion principle
22 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.
23 Resource Partitioning- Experiment #1: Explain this example of resource partitioning. How have the different species adapted to their competition?A. ricordiiA. ricordiiA. insolitusA. distichusA. insolitusA. alinigerA. christopheiA. distichusA. distichusA. christopheiA. cybotesA. cybotesA. etheridgeiA. etheridgeiA. insolitusFigure 19.7
24 2. Resource Partitioning There are two possible outcomes of competing species w/ identical niches (not just living in the same area)1. Extinction of one species2. Evolution of one species to use adifferent set of resourcesResource partitioning is the differentiation of niches that enables similar species to coexist in a community.
25 Reproductive Potential …Is an organism’s ability to grow at the fastest rate.(To replenish the species—innate!)
26 REPRODUCTIVE POTENTIAL COMPARISON R-selectedHint: Rapid ReproEarly reproductionShort life spanHi mortalityLittle/no parental careLarge # of offspring produced2. K-selectedHint: Longer ReproLate reproductionLong life spanLow mortalityHigh parental careSmall # of offspring produced
27 REPRODUCTION TYPESR-SELECTED TYPESK-SELECTED TYPE
28 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.
29 The Complexity of Community Networks The interrelatedness of interactions between species makes communities complexRecruitmentRelease of volatile attractantsChemical in salivaWoundingDetection by plantFigure 19.17