Presentation on theme: "CONSERVATION ECOLOGY. Objectives: I will be able to discuss how human activity is changing the Earth. I will be able to discuss the value of biodiversity."— Presentation transcript:
Objectives: I will be able to discuss how human activity is changing the Earth. I will be able to discuss the value of biodiversity.
Human activities threaten Earth’s biodiversity Biodiversity has three main levels: – Genetic diversity, – Species diversity, – Ecosystem diversity. Major threats to biodiversity: – Habitat loss, – Invasive species, – Overharvesting, – Global change (acid precipitation, climate change, air pollution, etc.).
Loss of biodiversity: Minimizes the chance of survival when faced with large environmental changes. Decreases stability of the ecosystem (in nature “everything is connected”). Poses ethical concerns. Earth is changing rapidly as a result of human action.
Common environmental problems: Eutrophication Refers to an excessive amount of nutrients in a body of water caused by runoff of nutrients from the land. Causes overgrowth of algae. Penetration of light is diminished which leads to decreased photosynthesis and decreased oxygen. When algae die, algal decomposers consume oxygen, further decreasing amount of oxygen available for animals.
Deforestation = conversion of forest to non-forest. Especially high in tropical rainforest. Due to logging, agriculture, urbanization, mining, oil exploitation, etc.
Ozone Depletion Ozone layer (in stratosphere) absorbs most of sun’s harmful UV radiation. Caused by chlorofluorocarbons (CFCs).
Pollution Present in water (fresh, ocean, ground water), land, air. Caused by pollutants from industry/automobiles and by nonbiodegradable wastes which cannot be broken down by natural processes.
Biological Magnification Toxins become more concentrated in successive trophic levels. The toxins cannot be broken down by normal chemical means, so they magnify in concentration as they move through the food chain.
Acid Precipitation Due to air pollutants (sulfur dioxide and nitrogen oxide) which increase the acidity of the rain. Damages plant tissues, leaches minerals from soil, causes death of trees, ruins stone buildings, kills zooplankton.
Global Climate Change Due to the greenhouse effect = heat retention by atmospheric gases such as CO 2 and methane. Global temperatures and sea levels are rising. Weather patterns are affected. Species are threatened.
What positive effects do we have on the environment?
Math Connection Energy Flow in a Hardwood Forest (kJ/m 2 ) What percent of the biomass in the forest community represented above is tied up in the shrub layer? Give your answer to the nearest whole number. Solar Radiation 2.5 X 10 6 Reflected 4.3 X 10 5 Absorbed 1.5 X 10 6 Transmitted 6.4 X 10 5 Energy Accumulated As Biomass 1.9 X 10 4 Energy Lost 1.4 X 10 6 Tree Layer 1.3 X 10 4 Shrub Layer ? Herb Layer 1.1 X 10 3