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Ecology Keep this in mind… In California… LOS ANGELES, Oct. 31 — A 10-year-old boy admitted that he accidentally started one of the largest of last week’s Southern California wildfires while playing with matches, enforcement officials say. Fanned by high winds and hot, dry weather, it spread quickly, driving 15,000 people from their homes, destroying 21 houses and 22 other buildings, injuring three people and blackening more than 38,000 acres In Iceland… Volcano in Iceland erupted twice in one month. The volcano has erupted for the second time in less than a month, melting ice, shooting smoke and steam into the air and forcing hundreds of people to flee rising floodwaters. The volcanic ash has forced the cancellation of many flights and disrupted air traffic across. SUCCESSION • What happens to an area after a disturbance? A predictable set of stages begins to change the area The changes are plant based; referred to as ecological succession. • What does it mean if you call someone a successor? EXAMPLE: The prince is the king’s successor. Ecological Succession Natural, gradual changes in the types of plant species that occupy an area You have studied pond succession! Primary Succession occurs on an area of newly exposed rock, sand, lava or any area that has not been occupied previously by a living (biotic) community Secondary Succession takes place where a community has been removed, i.e. a plowed field, clearcut forest, forest fire Complete the Succession WS What is a pioneer species? What is a climax community? Do Now What type of succession would occur on this land? If a fire occurred 100 years into succession of this land what type of succession would occur? HAND IN! Population Populations are dynamic! 3 important characteristics of populations: geographic distribution, density and growth rate What is density? 1. 2. 3. 4. Nutrients can limit plant growth Plant life grows best when all nutrients are present Not present? Limited nutrient Animals have limiting factors that affect growth as well: Density-dependent factors Density-independent factors Factors that influence density… Other Limiting Factors environmental influences that prevent species from obtaining a high population: generally populations decrease in size Two categories: Density-dependent limited factors Density-independent limited factors Density-dependent factor Density-dependent factors- affects populations due to their size Example- predation Density-independent factors Density-independent factors- affects all populations in similar ways, regardless of population size Example- hurricane Density-dependent or density-independent? Competition Earthquake Flood Parasitism Disease Seasonal cycles Available mates Do Now Define population density. Label each factor as d.dependent or d.independent: Territory (available space) Food tornado Population Growth Three factors affect population size Number of births Number of deaths Number of individuals that enter or leave the population Immigration: movement of individuals into an area Emigration: movement of individuals out of a population Population Exponential Growth (J-shaped graph) Logistic Growth (S-shaped graph) Exponential Growth Under ideal conditions with unlimited resources, a population will grow Industrial revolution: 1820-1870 Current population: ~6 billion Exponential growth faces problems… Exponential growth does not continue in natural populations for very long As resources become less available, the growth of a population slows or stops Logistic Growth Acceleration, high growth period, deceleration, fairly steady state Carrying capacity the number of individuals who can be supported in a given area within natural resource limits Carrying capacity- K Carrying capacity Patterns of Population Growth Human population cannot keep growing exponentially forever because Earth and its resources are limited… Study of human population is demography Birthrate, death rates and the age structure of a population help predict population increases and decreases of countries Age-structured diagrams Population pyramid Birth vs death rate within a population US population pyramid Human limits? World Resources Renewable Nonrenewable Renewable Resources A resource that can be continually reproduced Capable of being replaced by - natural ecological cycles or - sound management practices humans need to think of "renewable" as replenishable only in the right circumstances and within the laws of the balance of nature Do NOT Think… "Oh well, it's renewable so we can use as much as we want" "It's OK to log these forests- trees grow back” "Industries can pull all the water they want from the Great Lakes, without limitation. After all, water is a renewable resource, like air." Renewable" resources become non- renewable due to mis-management by humans and pollution of the environment by humans. What are examples of renewable resources? trees, wildlife, oxygen, and fresh water Nonrenewable Resources A resource that cannot reproduce Once the resource is used up- it is gone Humans are using up natural resources at a great rate and at a great cost to the health of the natural environment and life on Earth. What do humans use A LOT of? (think carbon cycle) Nonrenewable Resources Fossil fuels- oil, natural gas, coal How do they form? How long does it take for these resources to form? The world at night from space Human Impact Acid Rain What it is, where does it come from and what damage can it cause? What is acid rain? Acid rain is rain that is lower on the pH scale than normal rain water… Acid rain carries the chemicals sulphur dioxide and nitrogen oxide pH may vary: 5.5 to 3.0 (normal water is ~7-5.6) (ocean water ~7-8) Acid rain cycle Damage from acid rain Lakes and streams are normally acidic, acid rain can make them so acidic that it damages animal and plant life. Acid rain can cause a mass killing to trees. Area's can become very hazy and foggy due to acid rain linked to breathing and lung problems in children, and people who have asthma. Stone buildings and monuments are targets of damage from acid rain. Damage of acid rain Acid "rain" isn't just rain; acid snow, acid fog or mist, acid gas, and acid dust all have the same effect as acid rain. So much pollution!!! (don’t write, just read) 40% of America’s rivers and 46% of America’s lakes are too polluted for fishing, swimming, or aquatic life 1.2 trillion gallons of untreated sewage, storm water, and industrial waste are discharged into US waters annually. Polluted drinking waters are a problem for about half of the world’s population. Each year there are about 250 million cases of water-based diseases, resulting in roughly 5 to 10 million deaths. Each year, U.S. factories spew 3 million tons of toxic chemicals into the air, land, and water. Every year, one American produces over 3,285 pounds of hazardous waste. Seventy-three different kinds of pesticides have been found in groundwater, which is potential drinking water Over 80% of items in landfills can be recycled, but they’re not. What should be recycled? NOT GUM!!! Plastic bottles, cans, paper, card board Pollution… Biomagnification Humans use of DDT (Dichloro-diphenyl-trichloroethane) insecticide and pesticide (world-wide use) 30 years prior to its cancellation, a total of approximately 1,350,000,000 pounds of DDT was used domestically DDT is a persistent, toxic chemical which easily collects in the food chain posing a proven hazard to non-target organisms such as fish and wildlife and otherwise upsetting the natural ecological balance Biomagnification Prime example of a non-target animal that was hurt by the use of DDT The bald eagle- What can be done to help? Recycle Turn off electronics Take shorter showers Educate yourself! ALTERNATIVE ENERGY Alternative Energy The Alternative Energy Institute (AEI) was formed in 1977 at West Texas State University, Texas, USA Consequences are minimal renewable and are thought to be "free" energy sources lower carbon emissions, compared to conventional energy sources Alternative Energy These include Biomass Energy, Wind Energy, Solar Energy, Geothermal Energy, Hydroelectric Energy sources Alternative energy Human Impact What is the differences and similiarities between… Ozone layer depletion Greenhouse effect Global warming Ozone layer Affects earths climate Gas that occurs naturally vital role by shielding humans and other life from harmful ultraviolet light from the Sun Ozone depletion chemicals, such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) Depleted protective layer International agreement to limit emissions Greenhouse effect Affects earths climate, especially temperature Positive and natural occurrence Greenhouse gases: such as water vapor, carbon dioxide, ozone and methane Greenhouse gases slow down the rate at which heat is released back into space Too much of these gases is a bad thing! Greenhouse effect Global warming Affects the earths climate Especially temperature! Not only in the air but on land Overabundance of greenhouse gases higher temperature Burning of fossil fuel, deforestation Possible effects of global warming: Melting ice results in water level rising Stronger hurricanes Ice age More drastic weather cycles
