Presentation on theme: "Aim: How do abiotic (physical) limiting factors affect growth and survival in an ecosystem ? HW due Thurs Read chapter 5 pg. 118-127 Do Making Connections."— Presentation transcript:
Aim: How do abiotic (physical) limiting factors affect growth and survival in an ecosystem ? HW due Thurs Read chapter 5 pg. 118-127 Do Making Connections pg.127
Ecosystems and Growth One of the features of an ecosystem is that its growth is limited under normal conditions by competition for resources within the system and by external factors such as environmental changes
If the presence or absence of a factor limits the growth of the ecosystems elements, it is called a limiting factor. There are several abiotic factors that limit ecosystem growth, including temperature, precipitation, sunlight, soil configuration, and soil nutrients.
Observation of ecosystems in very different geographical regions
Identify the maximum and minimum values and describe the overall shape of the graph
Your task… What limits the North American Tundra ecosystem? Explain your reason and point out evidence from the graphs that support your answer. What limits the South African Grassland ecosystem? Explain your reason and point out evidence from the graphs that support your answer. Work in groups – 5 minutes
A situation that causes the growth of a population to decrease is called a limiting factor. Some limiting factors depend on the size of the population. Other limiting factors affect all populations in similar ways, regardless of the population size. Section 5-2 Interest Grabber Go to Section: What are limiting factors to population growth ?
Different factors can limit population growth How is the population size affected by these factors?
Number of Yeast Cells Time (hours) Carrying capacity Section 5-1 Figure 5-4 Logistic Growth of Yeast Population Go to Section: population growth… Logistic
Growth of Aphids Section 5-2 A Density-Dependent Limiting Factor Go to Section: Exponential Growth Unlimited resources Absence of predation No disease
Population Growth can be represented bycharacterized by represented by which cause a Exponential growth Logistic growth Falling growth rate S-shaped curve Limits on growth No limits on growth J-shaped curve Constant growth rate Unlimited resources Section 5-1 Concept Map Go to Section:
60 50 40 30 20 10 0 195519601965197019751980198519901995 2000 1600 1200 800 400 0 2400 MooseWolves Section 5-2 Figure 5-7 Wolf and Moose Populations on Isle Royale Go to Section: How would you explain what is happening to the moose and wolf population ?
Agriculture begins Plowing and irrigation Bubonic plague Industrial Revolution begins Section 5-3 Human Population Growth Human population growth Is there a Carrying Capacity for Homo sapiens?