1. Species Diversity

2. Questions for Today What is Species Diversity? What is Species Diversity? What is the difference between Species Richness and Species Evenness? What is the difference between Species Richness and Species Evenness? How Does Species richness affect Biodiversity? How Does Species richness affect Biodiversity?

3. What is Species Diversity? Species Diversity is the number of different species an ecosystem contains (species richness) combined with the relative abundance of individuals within each of those species (species evenness). Species Diversity is the number of different species an ecosystem contains (species richness) combined with the relative abundance of individuals within each of those species (species evenness). –Species Diversity is as major component of biodiversity.

4. What is Species Diversity? Species Diversity varies with their Geographic Location: Species Diversity varies with their Geographic Location: –Terrestrial plants and animals Highest towards the equator and lessens as we head to the poles Highest towards the equator and lessens as we head to the poles –Aquatic Plants and animals Highest where there is more sun available. Highest where there is more sun available.

5. Species Richness vs. Evenness A coral reef with many different types of species but at a low number would be described as having high species richness but low evenness A coral reef with many different types of species but at a low number would be described as having high species richness but low evenness A aspen forest with only aspen trees and a few individuals but at a high number would be described as having low species richness but high evenness. A aspen forest with only aspen trees and a few individuals but at a high number would be described as having low species richness but high evenness.

6. Variations in Species Richness and Species Evenness

7. How does Species Richness affect Biodiversity? High Species Richness creates a more stable environment High Species Richness creates a more stable environment –More Producers More NPP More NPP –More complex food chains and webs Allows organism to adapt to environmental stresses Allows organism to adapt to environmental stresses –Able to bounce back from catastrophes better.

8. Niches and Roles

9. Questions for Today What is a Niche? What are the differences between Generalist Species and Specialist Species? What are the different roles Species can play in the environment?

10. Ecological Niches Each species in an ecosystem has a specific role or way of life Ecological Niche = a species way of life or role in the community Includes everything that affects its survival and reproduction

11. Generalist Species vs. Specialized Species Some species have broad ecological roles and others have narrower or more specialized roles. Generalized species – species that can have broad niches. Extremely adaptable to a changing environment Flies, Rats, Cockroaches, white-tailed deer, raccoons, coyotes, humans, and many weeds.

12. Generalist Species vs. Specialized Species Specialist species – species that occupy narrow niches. May only live in a certain habitat, use only one type of food, or tolerate a certain climate condition. More Prone to extinction Tiger Salamanders – must live in fishless ponds Giant Panda – habitat loss, low birth rate Shorebirds Is it better to be a generalist or a specialist?

13. Roles for Organisms Niches can be divided into the roles species play in their community: Native Non-native Indicator Keystone Foundation

14. Native vs. Non-native Native species are those individuals that normally live and thrive in a particular ecosystem. Non-native species are those individuals that migrate or are accidentally or deliberately introduced to a particular ecosystem. Invasive, alien, or exotic

15. Native vs. Non-native Non-native species can be good or bad. Good NN Cows, chickens, and other domesticated animals Bad NN Kudzu Vine, Water Hyacinth, and Killer Bees

16. Indicator Species When an ecosystem or community starts to collapse, ecologist look at indicator species for the first warning signs. Indicator species are, generally, specialist species that are affected by a change in one or more key abiotic factors in the environment.

17. Indicator Species Examples of Indicator Species: Trout for water quality Birds for air quality Frogs a general measure of productivity in a region. Tropical Regions

18. Keystone and Foundation Species Keystone species have a large effect on the types and abundances of other species in an ecosystem. Keystone species are low in number and are usually prone to extinctions Extremely important Two major roles of Keystone Species Pollinator Top Predator Loss of Keystone Species usually lead to a population crash and other extinctions

19. Keystone and Foundation Species Foundation species play a major role in shaping communities by creating and enhancing their habitats in ways that benefit other species. Elephants push over trees and uproot plants to help new plants take root. Beavers create dams and cut down trees.