Presentation on theme: "Notes: Human Influences on Environment and Pollution (pg )"— Presentation transcript:
1Notes: Human Influences on Environment and Pollution (pg. 16-18) I. LOSS OF BIODIVERSITYBiodiversity- is the variety of life in an area. This is a necessity because organisms depend upon one another (food chain).
2Threatened Species Species population begins to decline rapidly Example: African Elephants
3Endangered Species: Number in population become so low that extinction is possible
4Extinction Disappearance of a species when the last member dies Since early 1980 40 plant and animal species have become extinct
5Causes of ExtinctionOverhunting: killing of organisms for food, fur, feathers or other body parts at a faster than the population can renew its numbers.Example: blue whale, tigers, snow leopards, elephants, rhinocerosesOverfishing: harvesting of fish or shellfish faster than the population can renew its numbersExample: Eastern oyster
6Eastern Oyster Keystone species along NC estuaries Serve 3 major roles: food source, clean the water, provide habitat (build reefs)Overharvested, water pollution and habitat destruction led to 90% decline in populationResult: increased pollution in estuaries and decline in other aquatic species.
7African ElephantsPopulation decline due to the poaching of elephants for their tusks which are made of ivory.
9II. What Humans Have Done to Affect Biodiversity Habitat Loss- Organisms lost homes and shelter because of human interaction
10DeforestationRemoval of all trees of a forest for either land development or wood supply.Not only results in habitat loss but also contributes to global warming as CO2 levels increase
11Piedmont Urbanization As the population grows in the piedmont region of NC, there is a demand for more land development (homes, schools, roads, shopping centers)This leads to habitat destruction
12Coastal Development Increased development to meet population increases Beach erosion leads to changes in natural habitats as well as alters beach ecosystems.
13Habitat Fragmentation- Separation of wilderness from other wilderness area. Construction of roads or buildings in nature
14Habitat Degradation- Damage to habitat by POLLUTION Habitat Degradation- Damage to habitat by POLLUTION. Example: acid rain or the depletion of the ozone layer.
15Keystone Species:A species that plays a critical role in the community of an ecosystemExample: Eastern oyster
16Introduction of invasive species An introduced species that is not native to that ecosystemCan wreak havoc due to having no natural predators or competitionExample:KudzuRodents/insects traveling on cargo ships from other countries
17Kudzu Imported from Asia in the 1800’s to help with soil erosion. Has outcompeted native plants and resulted in population decline of some small ground plants and can kill trees.Grows rapidly and few animals feed on it
18Resource Destruction: Renewable resources- can regenerate if they are alive or can be replenished by biochemical cycles as quickly as they are used.Examples: soil, water, air, forests
19Nonrenewable resources- cannot be replenished by natural processes as quickly as they are used. Examples: fossil fuels, minerals, metalsUse of new technology requires certain minerals that can depleted rapidly as use is increased
20Global WarmingThe overall warming of our earth (a.k.a. the greenhouse effect) caused by increased levels of carbon dioxide that is released naturally by respiration and by the burning of fossil fuels.See carbon cycle notes to review more causes of carbon dioxide release
21Global WarmingIncrease in temperatures has lead to ice caps and glaciers melting:increases sea level which can flood coastal townsResults in habitat loss for polar bears
22Global WarmingExtreme weather changes have been contributed to increases in global temperatureExample: Super storm Sandy
23Destruction of the Ozone Layer Caused by the use of chlorofluorocarbons (CFCs) (primarily found in aerosols and coolant systems)Ozone layer is a natural sunscreen for our earth, it is diminishing and allowing more ultraviolet (UV) rays to pass through which has been correlated to increased cases of skin cancer.
24Pesticide use- Rachel Carson wrote Silent Spring and made the public aware of the DDT pesticide problem
25Pesticides are used to kill pests but can sometimes kill organisms that aren’t targeted. Runoff can carry them into aquatic ecosystems.
26Bioaccumulation:Pesticides (or pollutants) are passed through the food chain
27Biomagnification:The highest amount of pesticides (or pollutants) are found at higher trophic levels due to the consumption of organisms with trace amounts of pesticides (or pollutants) at lower trophic levels.
28Biomagnification: Major animal affected: Bald eagles and peregrine falcons decreased due to soft shells from exposure to DDT. This resulted in fewer chicks surviving and hatching and a population decrease.
29Pollution:Pollutants that are released in one area often have an impact on a much larger area. The plume is the area that a substance touches (smoke stack in air or a pesticide in ground water)
30Pollution:Release of harmful substances or energy into air, water or soil.Burning fossil fuels releases carbon dioxideDeforestation reduces numbers of plants that take in carbon dioxideGround water or runoff carrying pesticides from crops into water supply
31Eutrophication: Excess nutrients are released into a body of water. Example: Waste lagoons on NC hog farms
32Waste LagoonsPhosphorous and nitrogen compounds such as nitrates can seep into the soilCarried to aquatic ecosystems by groundwater or runoffExcess nutrients cause a population explosion of algae creating an algal bloomAlgae thrives on nutrients and exceeds carrying capacity so they begin to dieDecomposers become active on the algae which uses more oxygenLess oxygen available to other organisms which results in death of other organisms
33Acid Rain Rain that has a pH lower than 5.6 Caused when sulfur and nitrogen released from the burning of fossil fuels combine with water in the atmosphereHarmful to plants and the animals that eat the plants