1. Invasive Species and Biodiversity

2. I.What is an Invasive Species? A.Alien Species (aka “non-native” species) 1.A species that does not naturally occur in a specific area. B. Invasive Species 1.A species that causes economic or environmental harm or harm to human health.

3. I.What is an Invasive Species? C. Why do alien species become invasive? 1.Lack of natural predators 2.Evolutionarily novel to environment 3.Invade already disturbed habitats 4.Posses invasive traits

4. II. Invasive Species and Biodiversity A.The Question: Do invasive species negatively affect biodiversity? 1.Argument: Invasive species have a positive effect on biodiversity i. many new species are introduced while very few go extinct, increasing biodiversity

6. II. Invasive Species and Biodiversity 2. Counterarguments i. Extinctions take time a.Species may not be extinct yet, but in the future there is a possibility for extinction. ii. Species composition and abundance are changed even if the number of species stays the same

10. II. Invasive Species and Biodiversity B. Candy Lab Step 1: a.Count the number of each “species” in your sample area b.Record your data in your data chart c.Share your data on the class data sheet

11. II. Invasive Species and Biodiversity B. Candy Lab Step 2: Record the following from the class data on your data sheet a.# of Individuals b.# of Species

12. II. Invasive Species and Biodiversity B. Candy Lab Step 3: An invasive species is introduced to your sample area. a.Randomly remove half of the individuals in your population due to the introduction of the invasive species

13. II. Invasive Species and Biodiversity B. Candy Lab Step 4: a.Recount the number of each “species” in your sample area b.Record your data in your data chart c.Share your data on the class data sheet

14. II. Invasive Species and Biodiversity B. Candy Lab Step 5: Record the following from the class data on your data sheet a.# of Individuals b.# of Species c.Cumulative # of Species d.Relative abundance

15. II. Invasive Species and Biodiversity B. Candy Lab Step 6: a.Graph the cumulative # of species for the class samples in the provided area on your data sheet b.Include a line for the samples taken before the introduction and after the introduction

16. II. Invasive Species and Biodiversity B. Candy Lab Discussion Questions a.Did the introduction of an invasive species affect biodiversity? Were there any extinctions? b.Did the relative frequencies of the species present in the area change? c.Did your graph of the cumulative # of species show any difference between the counts before and after the invasive species introduction? d.Are the differences significant?

17. II. Invasive Species and Biodiversity C. Scale-Dependent Effects on Biodiversity 1.Small spatial scales a.Communities and ecosystems 2.Large spatial scales a.Regional and global

18. II. Invasive Species and Biodiversity

22. habitat area

23. II. Invasive Species and Biodiversity Small Spatial Scale Large Spatial Scale habitat area Is more data always better?

24. II. Invasive Species and Biodiversity C. Scale-Dependent Effects on Biodiversity 3. Scientists hypothesize that invasive plant species decrease the density of native individuals, resulting in a scale-dependent effect of invasions on biodiversity. 4. When densities change too much, species are vulnerable to extinction.

26. III. Examples of Invasive Species and Their Effects A.Brown Tree Snake 1.Originally from Australia, introduced to Guam i. Lacks predators ii. abundant food source (many flightless birds are now extinct) iii. Filled an unfilled niche

27. III. Examples of Invasive Species and Their Effects B. Kudzu 1.Originally an ornamental plant from Asia 2.Can grow a foot a day and self fertilize 3.Takes advantage of disturbed habitats

28. III. Examples of Invasive Species and Their Effects C. Zebra Mussel 1.Introduced from the ballast waters in ships, originally from Europe 2.Destroys pipes

29. III. Examples of Invasive Species and Their Effects D. Problems caused by invasive species 1.There are 6,500 alien species in the United States 2.Second largest threat to native species 3.Threat to agriculture, human health 4.Economic losses exceed $120 billion each year in the US

30. III. Examples of Invasive Species and Their Effects E. Solving the invasive species problem 1.Prevent them from entering 2.Early detection 3.Understand how they succeed 4.Eradication and restoration