Population Ecology

3 CHARACTERISTICS OF A POPULATION: Density- individuals per unit area “natural population” 2) Growth Rate- change in the number of individuals of any species 3) Geographic distribution- area inhabited by a population

3 FACTORS THAT AFFECT POPULATION: # Of Births # Of Deaths # Of Individuals that ENTER and LEAVE a population

2 TYPES OF POPULATION GROWTH

1) EXPONENTIAL GROWTH Population grows EXTREMELY RAPID and at a CONSTANT RATE Unlimited resources Results: J-Shaped curve

2) LOGISTIC GROWTH Period of Exponential Growth, but will STOP or SLOW DOWN CARRYING CAPACITY: total # of individuals a population can support Limited Resources RESULTS: S-shaped curve Goes through a # of Phases

Human Population Growth

Predator – Prey Relationship

LIMITING FACTOR FACTOR THAT CAUSES THE POPULATION TO DECREASE Density Dependent Density Independent

Density-Dependent Limiting Factors Factors that depend on the SIZE of a population EXAMPLES: *Competition *Predation *Disease *Parasitism

Density-Independent Limiting Factors Factors that affect ALL population regardless of population size EXAMPLES: *Natural disasters *Weather *Human Activities

Changes in Ecosystems: Ecological Succession

What is Ecological Succession? Natural, gradual changes in the types of species that live in an area Can be primary or secondary

Primary Succession Begins in a place without any soil: Sides of volcanoes Landslides Flooding First, lichens that do not need soil to survive grow on rocks Next, mosses (nonvascular plant---does not have xylem or phloem) grow to hold newly made soil and are known as a PIONEER SPECIES (1st to inhabit an area)

Pioneer Species Low, growing moss plants trap moisture and prevent soil erosion Lichens break down rock to form soil.

Primary Succession Steps Simple plants (ex: mosses and ferns) grow in the new soil Simple plants die (adding more nutrients to the soil) thickening the soil and other plants begin to grow Process repeats; shrubs and trees survive Insects, small birds, mammals, etc move into an area and now can support a variety of life

Secondary Succession Begins in a place that already has soil and was once the home of living organisms Occurs faster and has different pioneer species than primary succession Example: after forest fires

Ecological Succession Recap 2 types of ecological succession: Primary Succession (no soil; ex: volcano lava flow with a pioneer species; longer process) Secondary Succession (existing soil; disturbance; faster process) Ecological Succession

Exit Ticket Only write the answer! You may use your notes. Place in basket with name when finished. No talking!!!! List 3 factors that affect population growth. What are 3 characteristics of a population? What type of growth goes through a period of rapid growth, and slows down or stops? What is the term for the largest # of individuals a population can hold? What type of growth grows at a constant rate? List 2 density-dependent limiting factors. List 2 density-independent limiting factors. Which type of succession begins in a place with no soil? Natural, gradual changes in the types of species that live in an area is known as _____________. Lichens, moss, and ferns are all example of which type of species? (Hint: 1st species to inhabit and area)

Human Impact on the Environment

Global Warming: in Earth’s average temperature due to the buildup of greenhouse gases which prevents heat from escaping

Caused by aerosol chemicals called chlorofluorocarbons (CFCs) CFC’s Ozone depletion Caused by aerosol chemicals called chlorofluorocarbons (CFCs) CFC’s Escape into atmosphere, reacts breaking down the ozone (O3, a protective atmospheric layer) UV rays penetrate the atmosphere and cause harm to many organisms

Human Population Current: 7+ billion Estimated: 9+ billion (2042)

Effect of Disease on a Population 1. AIDS---final stage of HIV disease which causes severe immune deficiency 2. Influenza--- seasonal infectious disease caused by an RNA virus 3. Tuberculosis (TB)--- contagious bacterial infection that involves the lungs

Effect of Disease on a Population 4. Dutch Elm Disease--- an introduced species caused by a fungus and spead by elm bark beetle 5. Pfiesteria--- associated with harmful algal blooms and fish kills in NC

Human Impact Negative Positive Acid Rain Reforestation Deforestation Habitat Destruction Invasive/Non-native Species (no natural predators) Ozone depletion from the release of CFCs Reforestation Crop Rotation Recycling Sustainable practice (Reduce, reuse, and recycle) Organic

North Carolina Ecosystems Acid Rain: effects in mountains Beach Erosion: beach is moving further inland Urban Development in the Piedmont: habitat destruction and water runoff Waste Lagoons: hog farms (1995 an 8 acre hog waste lagoon in NC burst, spilling 25 million gallons of manure in the New River. The spill killed about 10 million fish and closed 364,000 acres of coastal wetlands to shellfishing. Kudzu: as an invasive/non-native plant

Impact of Humans on Natural Resources

Non-renewable includes fossil fuels (petroleum, coal) Natural resources: Non-renewable includes fossil fuels (petroleum, coal) Renewable includes animals, plants, water, wind, etc. even renewable resources can run out

Pollution: Agricultural Homes Industry DDT Fertilizers Animal wastes (nitrogen) Homes Strong cleaning agents Industry Toxic gases and wastes Acid rain

Causes Climate Changes Deforestation Destruction of forest Caused by demand for wood products, need for space, farmland, housing, roads, etc Causes Climate Changes Increase in temperature Decrease in moisture Disrupts carbon cycle Soil erosion Loss of Biodiversity Habitat fragmentation

Habitat Fragmentation

Habitat Fragmentation

Pesticide Use and Bioaccumulation Pesticides negatively affects humans, animals, & the environment Pesticide use can lead to resistance in pests Pesticide concentration INCREASED/MAGNIFIED as you go up the food chain (Bioaccumulation) RESULTS: Ex: Toxicity in fish caused near extinction of fish eating birds

Sustainable Practices: environmental safe practice that promotes conservation Help preserve the standard of living for future generations Will provide clean air, water, fuel sources and air Practices: Recycle Use energy efficient appliances Use Solar Power Use Wind power Use Hydro power