How Species Interact With Eachother

1. How Species Interact With Eachother

2. Figure 53.1 • Community • Group of species living close enough together for potential interaction

3. Predation • A Predator eats the Prey • Predator adaptations • Locate & subdue prey • Prey adaptations • Elude & defend

4. Competition • Species competing for the same limited resource. • Competitive Exclusion Principle • One species will outcompete the other, driving one to extinction in the ecosystem

5. Parasitism • Parasite lives on or in its host organism • Parasites generally to do not immediately kill their host

6. Figure 53.9 Symbiosis • Mutualism(+/+) • Lichens (algae & fungus) • Ant and Acacia Tree • Commensalism (+/0) • Barnacles attached to a whale

7. Figure 53.5 Cryptic coloration • Camouflage

8. Aposematic coloration • Bright warning to predators

9. (b) Green parrot snake (a) Hawkmoth larva Figure 53.7a, b Batesian mimicry • Palatable or harmless species mimics a harmful model

10. (a) Cuckoo bee (b) Yellow jacket Figure 53.8a, b Müllerian mimicry • Two or more unpalatable species look like each other

11. What kind of mimicry? Red next to yellow, kill A fellow Red next to black, Friend to Jack

12. Concept Check! • According to the competitive exclusion principle, what outcome is expected when two species with identical niches compete for a resource? Why?

13. A B C D Community 1 A: 25% B: 25% C: 25% D: 25% Community 2 Figure 53.11 A: 80% B: 5% C: 5% D: 10% Species diversity • Greater diversity = greater stability

14. Quaternary consumers Carnivore Carnivore Tertiary consumers Carnivore Carnivore Secondary consumers Carnivore Carnivore Primary consumers Zooplankton Herbivore Primary producers Plant Phytoplankton Figure 53.12 A marine food chain A terrestrial food chain Trophic structure • Food chains • Feeding relationships • Limited to 4 or 5 trophic levels • Length of food chain limited by inefficiency of energy transfer

15. Humans Smaller toothed whales Baleen whales Sperm whales Elephant seals Leopard seals Crab-eater seals Squids Fishes Birds Carnivorous plankton Copepods Euphausids (krill) Phyto-plankton Figure 53.13 Food webs • Food chains are hooked together into food webs • Who eats whom? • A species may weave into a food web at more than 1 trophic level

16. Food Webs

17. Limits on food chain length • Energetic hypothesis • Limited by inefficiency of energy transfer • 10% • Dynamic stability hypothesis • Long chains less stable • Pop. fluctuations at lower levels magnified at higher levels

18. Community structure • Removing a species changes the community • Dominant species • Most abundant species or highest biomass in community • Keystone species • Exert important regulating effect on other species in a community

19. Figure 53.21a–c (a)Before a controlled burn.A prairie that has not burned forseveral years has a high propor-tion of detritus (dead grass). (c)After the burn. Approximately one month after the controlled burn, virtually all of the biomass in this prairie is living. (b)During the burn. The detritus serves as fuel for fires. Disturbances • Most communities are in a state of non-equilibrium due to disturbances • Fire, weather, human activities, etc. • Not all are negative

20. (b) One year after fire. This photo of the same general area taken the following year indicates how rapidly the community began to recover. A variety of herbaceous plants, different from those in the former forest, cover the ground. (a) Soon after fire. As this photo taken soon after the fire shows, the burn left a patchy landscape. Note the unburned trees in the distance. Ecological Succession • The sequence of community & ecosystem changes after a disturbance • Transition in species composition over ecological time

21. Succession • Primary • Begins in a virtually lifeless area without soil • Secondary • Existing community cleared, but soil is intact

22. Succession