1. V. Hassell Biology: The Dynamics of Life

2. Identify Common Limiting Factors Explain how limiting factors and ranges of tolerance affect distribution of organisms Sequence the stages of ecological succession Describe the conditions under which primary and secondary succession take place.

3. Why do weeds grow in areas where other plants die? Lack of rainfall causes most plants to die

4. Limiting factors restrict the Existence numbers Reproduction distribution of organisms

6. Mouse population is decreasing.

7. What factors could cause the fish to look like this

8. an existing community is gradually replaced by another community Each new community makes it harder for previous ones to survive

9. Occurs in an area where there has been no previously living community— Weathering rock erodes to soil Takes 200 – 1000 years to make 1 inch of topsoil

10. - final stable community that forms if land is left undisturbed. It is relatively stable

11. First species to move into an area Lichens Small plants Grasses

13. Secondary succession is the sequence of changes that takes place after an existing community is severely disrupted in some way Re-establishment or replacement of an existing ecosystem Mt. St Helens- Washington- 44,460 acres burned and flattened Yellowstone-fire Iceland- by 1850, all trees were gone- left barren and tundra like- seeds had to be imported

14. occurs in areas that previously contained life, and on land that still contains soil. Secondary succession occurs in areas that previously contained life. Soil must be present on this land, and the species that grow will differ from pioneer species

20. 1. Filling a lake or pond to be replaced with a (marsh, dry land, forest). 2. abandoned farms 3. fires or other disasters- 4. diseases & droughts

21. Plan an investigation by writing two questions that would test temperature as a limiting factor for an organism in an ecosystem. High temperatures Low temperatures

22. - there is a constant addition of new members through reproduction & a constant loss through death. balance = reproduction = death

23. Biotic Potential- maximum growth rate in ideal conditions- how big- how many offspring? Environmental Resistance- all factors which cause early death- lack of space, food, waste buildup

24. Population sampling- Instead of counting all the objects, a representative number is counted Counting populations Tagging animals Marked w ear tags Transmitters Trees w paint or ribbons Clumping groups together

26. Billions/date/time taken 1 1830 10,000yrs 2 1930 100 years 3 1960 30 years 4 1975 15 years 5 1986 11 years 6 1999 13 years Future- 10-30 billion estimated by 2100.

27. Problems w increasing human pop. Producing food for everyone. Should countries with surpluses give it to those without enough? Countries don’t grow at same rate. Should gov. control family size? Poisons used to control pest are poisoning food. Should they be banned?

28. disease Mid 14th Century- Black Plague Reduced England's pop. By 50% from 1348 - 1379. Famine Starvation Irish Potato Famine of the 1840’s killed 1 million A Famine in China during 1877- 1888 killed 9 million Pop. Change due to Disease The more densely populated- the faster the disease spreads Held pop. In check for thousands of years

29. Emigration- moving out of an area- decreases pop. Immigration- moving into an area- increases pop Legal immigration in US 1820-1987

30. Reproductive rate -only long term method of control

31. ½ of the humans that die each year are under the age of 5 Problems feeding all the people Especially in the countries where there is hunger Chemicals used to increase food production

32. Freshwater zones of a lake Estuaries salt marshes Marine (Saltwater) sea shores coral reefs ocean