Biodiversity

1. Biodiversity Chapter 14

2. Objectives • Be able to describe biodiversity • Understand what factors have resulted in a loss of diversity • Be able to describe the consequences of extinction • Understand how a loss in biodiversity changes communities and ecosystems

3. Biodiversity: the entire variety of living organisms Biodiversity

4. What results in a loss of biodiversity? • Habitat destruction • Habitat fragmentation • Introduced species • Overexploitation • Pollution

5. Habitat destruction • A habitat is where something lives • Habitat destruction results from a complete disregard for the land during development or via natural phenomena (fire, global weather change)

6. Habitat fragmentation • The “Chopping up” of habitat. • Often seen in suburban settings • Loss of top predators lead to disruption of organism numbers

7. Introduced species • Non-native species are brought over to “beautify”, enrich, or introduced by ignorance • Non-native species may out compete native species for resources

8. Overexploitation • Over exploitation of organisms can disrupt food chains and/ or resource partitioning

9. Pollution • Release of poisons, excess nutrients and other wastes into the environment • Excessive nutrients leads to eutrophication which can result in oxygen depleted areas in aquatic systems

10. What are the consequences of a loss in biodiversity? • Loss of resources • Disruption of communities • Changed Ecosystems • Psychological Effect

11. What Is A Community? • Many populations of organisms living together make up a community • The kind of interactions between different populations can influence community structure • Climatic events may also influence community structure

12. Relationships Between Species • Organisms impact not only their population but the populations of other organisms through their relationships with other organisms • In a community, there are three types of relationships between species • Mutualistic relationships (Mutualism) • Predator-Prey relationships • Competitive relationships

13. Mutualism • Both species involved in the relationship benefit from increased survival and reproductive success • Many types of mutualistic relationships • Behavioral mutualism • Pollinator mutualism

14. Predator-Prey Interactions • Predator – Prey interactions result in the one species benefiting (consumer) and the other being harmed (victim) • 4 main types • Predator-Prey • Parasite-Host • Pathogens that cause disease • Herbivores that eat plants

15. Competition • Competition results in both species being negatively affected by the interaction • Exploitation competition: species involved compete indirectly for a shared resource

16. How do we influenceecosystem structure? • The actions of humans disrupt energy flow and nutrient cycles within ecosystems • Loss of producers leads to loss of productivity • Nutrient cycles often are sped up as a result of human influence

17. Ecosystem Structure: Food Webs • A food web is a series of interconnected food chains • Each food chain demonstrates a consumer-victim relationship between the species involved

18. Food chains tend to be short with generally fewer then five links General progression is from producer (autotroph) to consumer (heterotroph) Energy stored as food is called biomass Producers tend to photosynthesize and include plants and blue-green bacteria Consumers are defined by what they eat Herbivores: eat plants Carnivores: eat meat Omnivores: eat both plant and meat Detrivore: eat decay products Trophic Levels

19. Why Are Food Chains Short? • Energy is lost at each step of the food chain • How is energy lost? • Not all the available biomass is eaten. • Not all the material eaten can be digested adequately • Much of the ingested material is used for energy or heat

20. Nutrient Flow • A nutrient is an essential chemical element used by a producer • C, N, P & S • Nutrient quantities are fixed and must be recycled through living and nonliving components of the ecosystem

24. Ecosystem Process Generation of Soils Control of the Water Cycle Removal of Wastes Energy Flow Nutrient Recycling Human Influence Agricultural practices have exposed soil to the weather resulting in great loss of topsoil. The cutting of forests and other human activities have allowed increased uncontrolled runoff leading to increased erosion and flooding. Untreated sewage wastes and runoff from farms and feedlots have led to increased water pollution. Some industries and nuclear plants have added thermal pollution to the environment.   The release of some gases from the burning of fossil fuels may be slowly increasing the Earth's temperature. (Greenhouse Effect). The use of packaging material which does not break down, burning of refuse, and the placing of materials in landfills prevents the return of some useful materials to the environment. Human Influence on Some Ecosystem Processes

25. Psyche