PRINCIPLES OF ecology

1. PRINCIPLES OF ecology Chapter 2

2. Organisms and their environment • Importance of understanding your environment • Ecology – the study of interactions that take place between organisms and their environment • Qualitative data • Quantitative data

3. Organisms and their environment • Abiotic and Biotic factors • Abiotic factors • nonliving parts of an environment • Biotic factors • living organisms of an environment

4. Organisms and their environment • All organisms depend directly or indirectly on other organisms • Biosphere – portion of Earth that supports life • Atmosphere, Land and Water • Apple peel analogy • Interconnected

5. Organisms and their environment • Levels of Organization • Organism – individual living thing • made of cells, uses energy, reproduces, responds, grows and develops • Population – a group of organisms, all of the same species, which interbreed and live in the same area at the same time • Members compete for food, water, mates, ect… • Competition increases when resources decrease

6. Organisms and their environment

7. Organisms and their environment • Levels of Organization • Community – made up of interacting populations in a certain area at a certain time • Interacting populations are interconnected • Ecosystem – made up of interacting populations in a community and the community’s abiotic factors • Two major types of ecosystems • Terrestrial – located on land • Aquatic – fresh and salt water

8. Organisms and their environment

9. Organisms and their environment • Habitat • Place where an organism lives out its life, its address • Change or disappear due to natural and human causes

10. Organisms and their environment • Niche • Strategies/adaptations a species uses • Specific needs • Survival • Reproduction • Energy use

11. Organisms and their environment • Niche • Populations in close proximity occupy different niches • Advantages • Rotting log example

12. Organisms and their environment • Survival Relationships • Predator-Prey • Consume plants, animals or both • Symbiosis – close and permanent association between organisms of two different species • Three basic types of symbiosis • Mutualism • Commensalism • Parasitism

13. Organisms and their environment • Survival Relationships • Symbiosis • Mutualism – both species benefit • Lichen, ants/acacia tree • Commensalism – one species benefits, one species is unaffected • Spanish Moss, Cattle Egret • Parasitism – one species benefits, one species is harmed • Brown-headed cowbirds

14. Lichen

15. Cattle Egret

16. Brown-headed Cowbird

17. Nutrition and Energy Flow • Producers • May be Autotrophs or Chemotrophs • uses light energy to make energy-rich compounds • Plants, green algae, some bacteria • Form base of all food chains/webs • Consumers (Heterotrophs) • Cannot make food, depend on autotrophs for energy • Five general feeding relationships

18. Nutrition and Energy Flow • Heterotrophic feeding relationships • Herbivore– feed only on plants • Rabbits, grasshoppers, beavers, squirrels, bees, whitetail deer and some humans • Carnivore – feed only on animals • Bobcat, coyote, owl, largemouth bass and snakes • Scavenger – feed on dead animals • Black vultures and turkey vultures • Omnivore – feed on both plants and animals • Bears, raccoons, opossums and most humans • Decomposer – break down and recycle nutrients • Some protozoans, many bacteria and most fungi

19. Nutrition and Energy Flow • Food Chains • Model used to show how matter and energy flow through an ecosystem • Arrows indicate direction of energy flow • Berries → Mice → Black Bear

20. Nutrition and Energy Flow • Trophic Levels – Feeding step that indicates the passage of energy • Producers/Autrotrophs – Energy base • Plants eat sunlight • Primary Consumer –Consumes producers • Grasshopper eats grass • Secondary Consumer – Consumes primary • Eastern bluebird eats grasshopper • Tertiary Consumer – Consumes secondary • Hawk eats Eastern bluebird

21. Nutrition and Energy Flow • Food Web • Model that shows all feeding relationships at each trophic level • Species may feed at multiple trophic levels • More realistic model

22. Nutrition and Energy Flow

23. Nutrition and Energy Flow • Ecological Pyramid – model that show how energy flows through an ecosystem • Organisms use energy for metabolism, building body tissue and producing heat • With each step in the pyramid, only 10%of the total energy is available at the next level • Law of conservation of mass • Biomass– total weight of living matter at each trophic level

24. Nutrition and Energy Flow