Unit 1 Review: Ecosystems

Introduction to Ecosystems

• Predator-prey relationship defined

  • Predator eats prey

• Symbiosis types: mutualism, commensalism, parasitism

• Competition in ecosystems due to limited resources

• Resource partitioning reduces competition impact

Food Webs and Food Chains

• Food web models energy and nutrient flow

• Positive and negative feedback loops in food webs

• Impact of species removal/addition on food web

Trophic Levels

• Ecosystems need continuous high-quality energy

• Energy flow from sun to producers to higher trophic levels

Primary Productivity

• Rate of solar energy conversion into organic compounds

• Gross primary productivity (GPP) and Net primary productivity (NPP)

• Adaptations of photosynthesizers to light

Energy Flow and the 10% Rule

• 10% rule in energy transfer between trophic levels

• Energy loss explained by thermodynamics laws

The Carbon Cycle

• Movement of carbon compounds between sources and sinks

• Reservoirs with fossil and modern carbon

• Carbon cycle in living things and decomposition

Page 2:

The Nitrogen Cycle

• Atmosphere as major nitrogen reservoir

• Nitrogen fixation by bacteria for plant use

• Nitrogen assimilation by plants

The Phosphorus Cycle

• Movement of phosphorus-containing molecules

• Reservoirs in rocks and sediments

• Phosphorus as a growth-limiting factor

The Hydrologic (Water) Cycle

• Movement of water between sources and sinks

• Oceans as primary water reservoir

Terrestrial Biomes

• Biomes with characteristic plant and animal communities

• Major terrestrial biomes and factors affecting resource distribution

Aquatic Biomes

• Freshwater and marine biomes

• Importance of freshwater for drinking water

• Role of algae in marine biomes

Unit 2 Review: Biodiversity

Intro to Biodiversity

• Genetic, species, and habitat diversity in ecosystems

• Importance of genetic diversity in population response

• Impact of habitat loss on specialist and generalist species

Adaptations

• Organisms adapt to environment over time

• Response to environmental changes for survival

Generalist & Specialist Species

• Advantages of specialist and generalist species in habitats

• Impact of habitat changes on species survival

Island Biogeography

• Study of ecological relationships on islands

• Evolution of specialist species on islands

• Threat of invasive species to specialists

K- and r- Selected Species

• Characteristics of K-selected and r-selected species

• Biotic potential and reproductive strategies

• Adverse effects of invasive species on K-selected species

Page 4

Ecological Tolerance

• Refers to the range of conditions an organism can endure before injury or death

• Applies to individuals and species

Ecosystem Services

• Four categories: provisioning, regulating, cultural, supporting

• Anthropogenic activities can disrupt these services

Natural Disruptions to Ecosystems

• Environmental consequences of natural disruptions can be significant

• Earth systems processes operate on different time scales

  • Periodic, episodic, or random occurrences

• Earth's climate changes due to various factors like CO2, sun's strength, and volcanic activity

Ecological Succession

• Succession is the gradual change in species diversity after a disturbance

• Two types: primary and secondary succession

• Keystone species and indicator species play crucial roles in ecosystem structure

• Pioneer species are the first to colonize a habitat during succession

Page 5

Populations

Ecological Footprints

• Compares resource demands and waste production for individuals or societies

Introduction to Sustainability

• Refers to human use of resources without depletion for future generations

• Environmental indicators guide sustainability efforts

Carrying Capacity

• Population overshoot leads to environmental impacts like resource depletion

• Dieback of population can occur due to lack of resources

Population Growth and Resource Availability

• Population growth is limited by environmental factors and resource availability

• Resource base limits population growth

Survivorship Curves

• Display survival rates of a cohort in a population

• K-selected and r-selected species follow different survivorship curves

Age Structure Diagrams

• Population growth rates can be interpreted from age structure diagrams

• Rapidly growing populations have a higher proportion of younger individuals

Page 6

Human Population Dynamics

• Birth rates, death rates, access to resources, and environmental factors affect population growth

• Factors limiting global human population include carrying capacity and basic needs

• Population growth affected by density-independent and density-dependent factors

Demographic Transition

• Transition from high to lower birth and death rates with development

• Developing countries have higher infant mortality rates and more children in the workforce

Total Fertility Rate

• Affected by various factors like age at first childbirth and access to family planning

• Stable population if fertility rate is at replacement levels

Rule of 70

• Approximates population doubling time based on growth rate

Page 7

Earth Systems

Plate Tectonics

• Describes motion of Earth's plates

• Convergent boundaries result in mountains, earthquakes, and volcanoes

• Divergent boundaries lead to seafloor spreading and rift valleys

• Transform boundaries form when plates slide past each other

• Maps show global plate boundaries and associated geological features.

Soil Formation and Erosion

• Soils formed through weathering and erosion of parent material

  • Organic material decomposition adds nutrients

• Categorized by horizons based on composition and organic material

• Erosion by winds or water can impact water quality

  • Soils filter and clean water as it moves through

Soil Composition and Properties

• Water holding capacity varies with soil types

  • Affects land productivity and fertility

• Particle size and composition affect porosity, permeability, and fertility

• Various methods to test chemical, physical, and biological properties for decisions like irrigation and fertilizer needs

  • Testing moisture, permeability, presence of nitrates and phosphates

Watersheds

• Watershed drains streams and precipitation to a common outlet

• Characteristics include area, length, slope, soil, vegetation, and divides

• Factors affecting weather and climate include sun's energy, latitude, mountains, and ocean temperature

Earth’s Atmosphere

• Made up of major gases with relative abundance

• Layers based on temperature gradients: troposphere, stratosphere, mesosphere, thermosphere, exosphere

Solar Radiation & Seasons

• Solar radiation is Earth's main energy source

• Intensity varies with the angle of the sun's rays

• Seasons and daylight hours influenced by Earth's tilt and rotation

Global Wind Patterns

• Result from intense solar radiation at the equator

• Coriolis effect causes wind deflection

• Convection cells determine wind direction

• El Niño and La Niña impact ocean temperatures and global weather patterns

Unit 5: Land and Water Use

Tragedy of the Commons

• Individuals exploit shared resources for self-interest, depleting resources

The Green Revolution

• Shift to new agricultural strategies like mechanization, GMOs, fertilization, and pesticides

• Positive and negative impacts on food production and the environment

Impacts of Agricultural Practices

• Tilling, slash-and-burn farming, irrigation, and fertilizers can cause environmental damage

Irrigation Methods

• Waterlogging and salinization issues

• Types of irrigation: drip, flood, furrow, spray

• Drip irrigation most efficient but expensive

Pest Control Methods

• Pesticides can lead to resistance in pests

• Genetic engineering for pest resistance can reduce genetic diversity

Page 11: Meat Production Methods

• Meat production is less efficient than agriculture, requiring 20 times more land for the same calories.

• Methods include CAFOs and free-range grazing.

  • CAFOs are crowded, generate organic waste, but are cost-effective.

  • Free-range grazing allows animals to graze on grass, producing healthier meat.

• Overgrazing leads to desertification and soil erosion.

• Less meat consumption can reduce emissions, conserve water, and improve soil.

Impacts of Overfishing

• Overfishing leads to fish scarcity, harming biodiversity and communities.

• Solutions include aquaculture, fishing limits, and protected areas.

Integrated Pest Management

• IPM combines methods to control pests while minimizing environmental impact.

• Reduces risks of pesticides to wildlife and human health.

• Includes biological, physical, and limited chemical methods.

Page 12: Aquaculture

• Aquaculture is efficient but can contaminate water and harm wild fish.

• High fish density in aquaculture leads to disease spread.

Sustainable Forestry

• Mitigation methods for deforestation include reforestation and sustainable harvesting.

• Protects forests from pathogens using IPM and prescribed burns.

Clearcutting

• Economically beneficial but causes soil erosion, flooding, and climate change.

• Trees absorb pollutants and cutting them releases carbon dioxide.

Unit 6: Energy Resources and Consumption

• Nonrenewable energy sources are fixed, while renewable sources can be replenished.

• Fossil fuels are widely used globally, especially in developing countries.

• Energy consumption increases with industrialization and development.

Fuel Types and Uses

• Wood, peat, coal, natural gas, and crude oil are common fuel sources.

• Fossil fuels can be converted into specific types for different uses.

• Cogeneration produces heat and electricity from a single fuel source.

Distribution of Energy Resources

• Global distribution of energy resources is uneven due to geological factors.

Page 13: Fossil Fuels

• Combustion of fossil fuels releases carbon dioxide and water, producing energy.

• Extraction methods include fracking, which poses risks to groundwater.

Nuclear Power

• Generated through fission of uranium-235, producing heat for electricity.

• Radioactive waste disposal is a long-term challenge.

• Nuclear power is cleaner but produces thermal pollution and solid waste.

• Accidents like Three Mile Island, Chernobyl, and Fukushima have environmental impacts.

Page 14

Energy Sources

• Biomass

  • Produces heat at low cost but emits harmful gases and contributes to deforestation

  • Ethanol as a gasoline substitute has low energy return

• Solar Energy

  • Photovoltaic cells capture sunlight for electricity

  • Active systems use solar energy for heating with equipment

  • Passive systems absorb heat without mechanical equipment

• Hydroelectric Power

  • Generated through dams or turbines in rivers

  • Tidal energy uses tidal flows to turn turbines

• Geothermal Energy

  • Obtained from Earth's heat, but costly and can release hydrogen sulfide

• Hydrogen Fuel Cell

  • Uses hydrogen and oxygen to produce electricity and water

Page 15

Energy Sources (cont.)

• Wind Energy

  • Uses moving air to generate electricity

  • Renewable but can harm birds and bats

• Energy Conservation

  • Methods include adjusting thermostat, using energy-efficient appliances

  • Large-scale methods involve improving fuel economy and green building design

Air Pollution

• Indoor Air Pollutants

  • Include carbon monoxide, particulates, VOCs, and lead

• Outdoor Air Pollution

  • Coal combustion releases pollutants like CO2, sulfur dioxide

  • Fossil fuel combustion produces nitrogen oxides leading to ozone and acid rain

• Clean Air Act

  • EPA regulates air pollutants to protect human health

Page 16

Air Pollution Effects

• Acid Rain

  • Caused by nitrogen oxides and sulfur oxides, affecting soil, water, and biodiversity

• Photochemical Smog

  • Formed from nitrogen oxides and VOCs, harmful to health

• Air Pollution Solutions

  • Include regulatory practices, alternative fuels, and pollution control devices like catalytic converters

• Stratospheric Ozone Depletion

  • Caused by CFCs and natural factors, important for life on Earth

Overall, various energy sources have pros and cons in terms of environmental impact and cost. Air pollution from indoor and outdoor sources poses health risks, but regulations and solutions are in place to mitigate these effects.

Page 17

Ozone Depletion

• Crystals in the atmosphere react with CFCs to form the ozone hole over Antarctica.

• Decrease in stratospheric ozone leads to increased UV rays reaching Earth's surface.

• UV ray exposure can cause skin cancer and cataracts in humans.

• Mitigation of ozone depletion involves replacing ozone-depleting chemicals with substitutes like HFCs.

Noise Pollution

• Noise pollution causes physiological stress and hearing loss.

• Sources include transportation, construction, and industrial activities.

• Effects on animals include stress, communication disruption, damaged hearing, and changes in migratory routes.

Water Pollution & Human Health

• Equatorial climates spreading lead to the spread of pathogens and infectious diseases.

• Impoverished areas lack sanitary waste disposal, leading to the spread of infectious diseases.

• Various infectious diseases like Plague, Malaria, Cholera, and Tuberculosis are caused by pathogens.

Page 18

Sources of Pollution

• Point sources are identifiable, like smokestacks, while nonpoint sources are diffuse, like urban runoff.

• Human impacts on ecosystems include physiological stress, limited growth, and death due to pollutants.

• Coral reefs suffer from factors like increasing ocean temperatures and sediment runoff.

Oil Pollution

• Oil spills in marine waters cause suffocation, poisoning, and hindrance to survival of organisms.

• Economic consequences on fishing and tourism industries due to oil washing up on beaches.

Nutrient Pollution & Eutrophication

• Eutrophication from agricultural runoff leads to algal blooms and oxygen depletion.

• Hypoxic waterways and oceanic dead zones result from nutrient pollution.

• Thermal pollution affects organisms by releasing heat into water.

Page 19

Bioaccumulation and Biomagnification

• Bioaccumulation is the absorption of substances by living organisms, while biomagnification increases concentration in higher trophic levels.

• Persistent substances like DDT, mercury, and PCBs can cause harmful effects in ecosystems and humans.

• Heavy metals like mercury can bioaccumulate and impact drinking water supply.

Types of Toxins

• Heavy metals, carcinogens, endocrine disruptors, and POPs are harmful toxins.

• Examples include mercury, lead, PCBs, dioxin, and flame retardants.

• Endocrine disruptors can lead to birth defects and neuro-developmental disorders.

Toxins and Solid Waste Disposal

• Mercury, Lead, DDT, PCBs, Dioxin: Various toxins affecting human health.

  • Mercury: Neurotoxin from burning coal.

  • Lead: Neurotoxin previously in pipes, gas, and paint.

  • DDT: Banned pesticide in the US, an endocrine disruptor.

  • PCBs: Carcinogens and endocrine disruptors from industrial products.

  • Dioxin: Carcinogen from burning trash or fossil fuels.

• Solid Waste Disposal:

  • Types of Waste: Generated in various sectors like domestic, industrial, and agricultural.

  • Impacts: Contamination of groundwater and harmful gas release from landfills.

  • Landfills: Components like liners, leachate collection, and methane collection systems.

  • Issues: Dumping waste in oceans leading to pollution and harm to wildlife.

  • E-waste: Contains hazardous chemicals like lead and mercury, impacting groundwater.

  • Decomposition: Factors affecting landfill decomposition like trash composition and microbial conditions.

  • Incineration: Reduces solid waste volume but releases air pollutants.

  • Illegal Disposal: Environmental problems from items like rubber tires left in piles.

Waste Reduction and Sewage Treatment

• Waste Reduction Methods:

  • Recycling: Converts waste into raw materials for new products.

  • Composting: Decomposes organic matter into fertilizer.

  • E-waste Reduction: Recycling and reuse methods.

  • Incineration: Reduces trash volume and can generate electricity.

• Sewage Treatment:

  • Primary Treatment: Physical removal of large objects.

  • Secondary Treatment: Bacteria breakdown of organic matter.

  • Tertiary Treatment: Removal of pollutants using ecological or chemical processes.

Global Change and Climate Change

• Greenhouse Effect:

  • Greenhouse Gases: Carbon dioxide, methane, water vapor, nitrous oxide, and CFCs.

  • Impact: Necessary for Earth's surface temperature but can lead to environmental problems.

• Global Climate Change:

  • Effects: Rising temperatures, melting ice, rising sea levels, and displacement of populations.

  • Impacts on Ecosystems: Changes in marine ecosystems, soil viability, and polar regions.

• Ocean Warming and Acidification:

  • Causes: Increase in greenhouse gases leading to habitat loss and coral bleaching.

  • Ocean Acidification: Decrease in pH due to increased CO2 concentrations, damaging coral reefs.

Invasive Species

• Invasive species can thrive outside their normal habitat, threatening native species.

  • They reproduce quickly and outcompete native species for resources.

• Control methods include physical removal and prevention through inspecting boats, shipping crates, and luggage.

Endangered Species

• Factors leading to species endangerment include hunting, competition with invasive species, limited diet, and habitat requirements.

• Species that can adapt quickly or move to new environments are less likely to face extinction.

• Selective pressures like resource availability, environmental conditions, and biological factors can impact species.

• Strategies to protect animal populations include criminalizing poaching, protecting habitats, and legislation.

Human Impacts on Biodiversity

• HIPPCO factors (habitat destruction, invasive species, population growth, pollution, climate change, overexploitation) decrease biodiversity.

• Habitat fragmentation, caused by human activities, decreases biodiversity and makes habitats prone to invasive species.

• Global climate change can cause habitat loss.

• Overfishing leads to scarcity of fish species, affecting biodiversity and communities.

• Domestication of organisms for economic returns can negatively impact biodiversity.

Mitigating Biodiversity Loss

• Mitigation strategies include creating protected areas, using habitat corridors, promoting sustainable land use practices, and restoring lost habitats.

• Legislation like the Endangered Species Act and CITES protects species.

• Various environmental acts regulate air and water pollution, hazardous waste, and endangered species trade.

Thermal Inversion

• During thermal inversion, air temperature at the Earth’s surface is cooler than at higher altitudes.

• Thermal inversion traps pollution close to the ground, especially smog and particulates.

Mining

• Mining operations accessing lower grade ores increase resource use, waste, and pollution.

• Surface mining, like strip mining, removes overburden, leading to erosion.

• Mining waste includes soil, rocks, and slag or tailings.

• Mining impacts habitats, groundwater, and air quality.

Impacts of Urbanization

• Urban runoff reduction is essential to