Download Unit 9: Ecology A. Definitions 1. biotic​(bio = living)

Unit 9: Ecology A. Definitions 1. biotic​(bio = living)
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– living or once living organism in an ecosystem 2. abiotic​(a = no or not)
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– non­living factor in an ecosystem a. ex : sunlight, water, temperature, soil 3. ecosystem ­ a community of organisms that interact with each other and abiotic factors in the environment 4. biodiversity – genetic variation within a population a. both abiotic and biotic factors determine where an organism can live and how much the population can grow 5. biosphere – any aspect of Earth that supports life a. a variety of ecosystems make up the biosphere b. extends from oceans to the atmosphere B. Biomes 1. a biome – group of ecosystems that share both biotic and abiotic conditions 2. biomes are characterized by their climates, as well as plant and animal life 3. Examples : Biome Water Temperature Soil Plants Animals Desert Tundra Taiga (coniferous forest) Temperate Deciduous Forest Grassland Tropical rain forest C. Limiting Factors 1. limiting factors – anything that restricts the size of a population from reaching its full potential 2. Abiotic limiting factors a. light b. heat c. nutrients d. water e. air f. space 3. Biotic limiting factors a. organic matter b. predation c. competition 4. limiting factors for human population growth a. food supply b. space c. disease d. natural disasters 5. carrying capacity – maximum number of organisms an ecosystem can support a. limiting factors determine carrying capacity b. humans have not yet reached our carrying capacity D. Biodiversity Worldwide is Important 1. provides us with food (produce for consumption and feed for animals) 2. used for medical discoveries 3. provides us with clean water and oxygen to breathe 4. allows for ecosystems to rebuild after major disturbances 5. prevents disease 6. helps species adapt to changes in their environment 7. aesthetically beautiful E. Negative Effects of Human Population Growth 1. reduces the amount of space available for habitats for plants and animals 2. increases pollution and resource consumption a. overharvesting due to deforestation to produce fertile farmland 3. humans introduce invasive species (species not native to a particular area) a. causes competition with the native species for food and space 4. aerosols – minute particles suspended in the atmosphere that scatter and absorb light a. aerosols can change how clouds reflect and absorb sunlight b. aerosols are released by i. volcanoes ii. desert dust iii. burning fossil fuels 5. CFCs (chlorofluorocarbons) – nontoxic, nonflammable chemicals contains carbon, chlorine, and fluorine used in the manufacture of aerosol sprays and refrigerants a. once CFCs reach the ozone layer, they react with UV rays, releasing chlorine gas which breaks down ozone 6. industry – release large amounts of CO​2​ into the atmosphere, increasing greenhouse gases 7. over­farming – increases the amount of CO​2​ released into the atmosphere 8. habitat destruction and degradation 9. reduction in natural resources 10. reduce biodiversity F. Invasive Species 1. invasive non­native species (aka exotic species) were brought here for use as ornamental lawn or garden plants 2. when the invasive organism is able to survive and reproduce, it can invade the natural habitat and crowd out the native species reducing biodiversity 3. habitats with low plant diversity can be poor for wildlife a. ex : the absence of sharp thorns on exotic plant and differing branch patterns can allow predators easier access to nests G. Ways Humans Can Help the Environment 1. use cleaner transportation methods 2. add energy­savings features to your home 3. adopt energy saving habits (ex – turn off lights) 4. reduce your food footprint (eat less meat) 5. reduce your housing footprint (less yard space) 6. choose sustainable building materials, furnishings, and cleaning products 7. adopt water saving habits 8. reduce the quantity of good and services H. Acid Rain 1. when sulfur dioxide and nitrogen oxides are released into the environment and mixed with water and other chemicals they create acidic compounds (sulfuric acid and nitric acid) 2. these acids become part of the water cycle 3. the causes of acid rain a. volcanoes b. decaying vegetation c. burning fossil fuels