Bell ringer on page 93 Terrestrial plants have stomata on the surface of their leaves. A single stomata is surrounded by two guard cells that change shape in response to environmental factors and open or close the stoma. Which of the following best explains how the structure of the leaf is used in processes that occur in plants? A. Water enters the plant through the surface of the leaf for transpiration B. Gases for photosynthesis are exchanged through the surface of the leaf. C. Energy for cellular reproduction is absorbed through the surface of the leaf. D. Carbon dioxide enters the plant through the surface of the leaf for cellular reproduction.

Current World Population http://www.worldometers.info/world-population/

Kaibab Deer Case Study

Kaibab Deer Case Study Let’s read the introduction and objectives. Materials: pencil Look at the blank graph on page 2. Notice the X and Y axis. The Y-axis is in thousands. Go back to page 1. Follow the procedures exactly as they are written and go in order. You cannot skip ahead. Read everything. Example – when you get to step 3 you should only answer questions #1-4; then you should go back to step 4 in the procedures! Read the objectives and intro together as a class. Show them the blank graph on page 2 that they will be using. Remind them of the importance of following procedures EXACTLY and not to skip ahead. Show them step 3 as an example (they will try to answer all the analysis questions without doing the lab because they didn’t read the procedures).

KEY: ___ = Table 1 ---- = Table 2

What factors influence the carrying capacity of populations? SC.912.L.17.5: Analyze how population size is determined by births, deaths, immigration, emigration, and limiting factors (biotic and abiotic) that determine carrying capacity. What factors influence the carrying capacity of populations?

Vocabulary to keep in mind… Population: collection of individuals from the same species in a defined area Abiotic: non-living parts of an ecosystem such as the weather, water, and type of land Biotic: living factors such as food sources, predators, and competition Density-dependent: limiting factors that affect organisms based on the number of individuals in the area, such as food and water Density-independent: limiting factors that positively or negatively contribute to survival regardless of population size, such as floods, earthquakes, widespread disease, and fire Changes in populations can impact the biodiversity of an area. Those changes can be permanent or temporary and can result in the reduction or elimination of a population.

What is the Carrying Capacity of Walla Walla Island? Key Point 1 Carrying Capacity = The number of individuals that an ecosystem can support. What is the Carrying Capacity of Walla Walla Island? Use the graph to show how this is represented graphically.

Why might the line still wiggle? Key Point 2 When a population reaches its carrying capacity it is at equilibrium and is stable. Why might the line still wiggle?

Guided Practice What is the carrying capacity? Why do you think the actual population is not the same as the carrying capacity? What is the carrying capacity of this population? Why do you think the actual population is not the same as the carrying capacity?

Key Point 3 Factors that can cause a population to decline. Limiting Factors – something in the environment that limits growth of a population Deaths Emigration – movement of individuals out of a population Emigration= Exit

Guided Practice What is a limiting factor? What are some limiting factors for a population of fish? What are some limiting factors for a population of sunflowers? What is a limiting factor? Anything in the environment (biotic or abiotic) that can limit population growth. *To get students to answer the following questions push them to think about what things do these organisms need to survive… can any of those things be limited? What are some limiting factors for a population of fish? Amount of dissolved oxygen, availability of food, pH of the water, temperature of the water What are some limiting factors for a population of sunflowers? Amount of sunlight, amount of water, amount of nutrients in the soil, concentration of carbon dioxide

Key Point 4 Factors that can cause a population to increase: Births Immigration – movement of individuals Into a population. Immigration=in Abundance of resources and/or a lack of competition

Key Point-5 With out limits, a population will continue to grow forever. We call this exponential growth. (Hint= x2)

Populations

Populations Factors limiting population growth Density-dependent factors: Mortality due to disease Competition Shortage of food or prey Predation or parasitism Accumulation of waste Shortage of space or territory

Populations Factors limiting population growth Density-independent factors: Mortality due to weather Mortality due to natural disasters

Population Growth – 2 Types- Key Point 6 Logistic Growth Exponential Growth Growth is affected by limiting factors, such as space or food supply Creates a S-shaped curve, with a maximum population or carrying capacity Occurs for most organisms Growth increases rapidly with no limitation on its size Creates a J-shaped curve Occurs for bacteria and invasive species

Review Why does the wolf population generally rise whenever the moose population increases?

Graph Practice The dashed line indicating the carrying capacity for the mouse population is correctly shown on which graph?

Kaibab Deer Case Study

Kaibab Deer Study Questions What was the relationship of the deer herd to the carrying capacity of the range in 1915? 1920? 1924? Did the Forest Service program appear to be successful between 1905 and 1924? Do you think any changes had occurred in the carrying capacity of the range from 1900 to 1940? Why do you think the population of deer in 1905 was 4000 when the range had an estimated carrying capacity of 30,000?

Kaibab Deer Study Questions Without the well-meaning interference of humans, what do you think would have happened to the population after 1905? What major lessons were learned from the Kaibab deer experience? If the lessons learned from the Kaibab deer studies had been known then, what recommendations would you have made in 1915? 1923? 1939? What future management plan would you suggest for the Kaibab deer herd?