Transcript Bio1001Ch42
Community Interactions and Human impact Chapter 42-45 __________ - All the populations that live together in a habitat ___________ -the type of place where individuals of a species typically live _________- Everything it takes to survive survive and reproduce Species Interactions • Most interactions are neutral • ___________________ helps one species and has no effect on the other • ___________________ helps both species • _________ and parasitism both benefit one species at a cost to another Obligatory ________________• Example- The Yucca and the yucca moth – Each species of yucca is pollinated only by one species of ______ – Moth larvae can grow only in that one species of _______ __________ •______________ promotes traits that help prey escape predation •Camouflage •It also promotes traits that make •Warning coloration _______________ more successful at•Mimicry capturing prey Moment-of-truth defenses ______________ Ecology • Natural restoration of a damaged community can take a very long time • Active restoration is an attempt to reestablish biodiversity in an area • ______________ are actively working to restore reefs, grasslands, and wetlands Community _________ • Disturbances can cause a community to change in ways that persist even if the change is reversed Species Introductions •Introduction of a nonindigenous species can decimate a community •No natural ___________or controls •Can outcompete _______________species Examples of instability _______________ in Lake Victoria • This predator ate native cichlids; drove many species to extinction Rabbits in ____________ • Rabbits were introduced, but without predators, their numbers soared ______________ in Georgia •No natural herbivores, pathogens, or competitors •Grows over landscapes and cannot be dug up or burned out Diversity by Latitude • Diversity of most groups is greatest in __________; declines toward poles Ant diversity Human Effects 1. ________________cycle 2. __________ cycle 3. _____________cycle 1. Phosphorous cycle •Phosphorus is part of _______________and all ________________ •most prevalent limiting factor in ecosystems •phosphorus runoff is causing ___________ of waterways Phosphorus Cycle mining excretion FERTILIZER GUANO agriculture uptake by autotrophs MARINE FOOD WEBS weathering DISSOLVED IN OCEAN WATER uptake by autotrophs weathering DISSOLVED IN SOILWATER, LAKES, RIVERS death, decomposition sedimentation death, decomposition leaching, runoff setting out uplifting over geolgic time MARINE SEDIMENTS ROCKS LAND FOOD WEBS 2. ___________ cycle diffusion Atmosphere Bicarbonate, volcanic action carbonate Marine food TERRESTRIAL webs ROCKS Terrestrial Rocks photosynthesis Land Food Webs Soil Water Peat, Fossil Fuels Marine Sediments weathering •Atmospheric carbon is mainly ________________ •Carbon dioxide is added to atmosphere by Aerobic respiration, volcanic action, burning fossil fuels •Removed by _____________________ 2. Carbon cycle Greenhouse Effect • Greenhouse gases (CO2, CFCs, methane) impede the escape of heat from Earth’s surface CO2 •The average level is steadily increasing Human impact Burning of fossil fuels and deforestation are contributing to the increase 2. Carbon cycle Global Warming • Long-term increase in the temperature of Earth’s lower atmosphere 3. Nitrogen cycle • Nitrogen is used in _______________ and _______________ • Main reservoir is nitrogen gas in the __________________ Human impact •Humans increase rate of nitrogen loss by clearing _______________________ •Humans increase nitrogen in water and air by using fertilizers and by burning _______________ •Too much or too little nitrogen can compromise plant health Human Impacts ___________ • Carbon oxides •We use energy/ alter environment at astonishing rate • Sulfur oxides • Nitrogen oxides • Volatile organic compounds • Photochemical oxidants • Suspended particles ___________ Smog • Gray-air smog • Forms over cities that burn large amounts of coal and heavy fuel oils; mainly in developing countries • Main components are sulfur oxides and suspended particles __________ smog • Brown-air smog • Forms when sunlight interacts with components from automobile exhaust • ______________ are the main culprits Thermal inversion •Weather pattern in which a layer of cool, dense air is trapped beneath a layer of ______ air cool air warm inversion air cool air Acid Deposition • Caused by the release of __________ and nitrogen oxides • Coal-burning power plants and motor vehicles Very high acidity (pH 4.2-4.4) are major sources Sensitivity to acid deposition Moderate to high acidity (pH 4.2-4.4) ______ Thinning South America • Seasonal loss of ozone is at highest level ever recorded Antarctica Result of ozone thinning •Increased UV radiation • UV damages ____ • UV affects plants productivity) Protection efforts • CFC production halted • Methyl Bromide phased out • _____ recovery time Garbage • Mostly developed nations • 50% volume is ____________________ • Recycling can reduce pollutants, save energy, ease pressure on landfills Land use • Almost ___ percent of Earth’s land is used for agriculture or grazing • About ____the Earth’s land is unsuitable for such uses • Remainder could be used, but at a high _________ cost Green Revolutions • Improvements in _________________ – But mechanized agriculture requires pesticides, fertilizer, fossil fuel • Improving genetic _________ of crop plants Deforestation • ____________ acres logged each year – Wood is used for fuel, lumber – Land is cleared for grazing or crops •forest loss are greatest in Brazil, Indonesia, Mexico, and Columbia Results •Soil leeching •Flooding 1620 1850 1850 (pockets only) 1990 Desertification The __________ • Occurred in the 1930s in the Great Plains – Overgrazing and prolonged drought left the ground bare • 1934 winds produced dust storms that stripped about _______ acres of topsoil Water Use and Scarcity • Earth’s water is too ________ for human consumption • ______________________ is expensive • __________________ is the main use of freshwater Ogallala Aquifer •Overdrafts have depleted ______the water from this nonrenewable source Human Impact • We use energy/ alter environment at astonishing rate Nuclear ___ Renewable- __% Hydropower, geothermal, solar 7% Biomass 3% Natural Natural gas gas Fig. 45.16 Hydropower, geothermal, solar 6% Renewable- __% Nuclear Nuclearpower 1% __% Biomass 35% 26% 25% Naturalgas Natural gas 7% 7% Coal Coal 25% 25% Oil Oil 37% 37% Developed countries DEVELOPED COUNTRIES Oil Coal 25% 25% Oil Oil 26% 26% Developing countries DEVELOPING COUNTRIES 1. Nuclear Energy • Used extensively in some energy-poor developed countries • Little support in the ________________ • Emits fewer air pollutants than burning coal, but creates radioactive wastes • Potential for meltdown ________ Accident - 1986 •Core meltdown at a nuclear power plant in the Ukraine •____ immediate deaths, radiation sickness and death for others •Cloud of radiation spread by winds across Europe 2. ___________ Energy • Photovoltaic cells use sunlight energy to split water • ________ gas produced in this way can be used as fuel or to generate electricity • Clean, renewable technology 3. ____ Energy • An indirect use of solar energy • Wind farms are arrays of ____________ • Can supplement needs of some regions but is not dependable enough on it own 4. ______ • Energy is released when _______________ fuse • This process produces solar energy • Attempts to mimic this process on Earth require use of lasers, magnetic fields • Not yet a _________________ viable energy source