1. Species Interactions Clarifying Objective 2.1.3 Explain various ways organisms interact with each other including predation, competition, parasitism, and mutualism.

2. Within all ecosystems, species interact in various ways. Photosynthetic organisms convert carbon dioxide and water into food and oxygen for the rest of the organisms in the ecosystem. Interactions within Ecosystems Animals produce organic waste that plants use as fertilizer so they can grow healthy and strong.

3. Decomposers recycle minerals and other nutrients within the ecosystem. Interactions within Ecosystems Certain bacteria “fix” atmospheric nitrogen into an organic form that plants can use and pass on to animals.

4. Symbiosis However, sometimes two different species will form a close and permanent relationship that then becomes part of each of the species niches. These close, permanent relationships between two different species is called symbiosis. Lichen

5. Symbiosis Lichen is a symbiotic relationship between different species of algae and different species of fungi. Fungus Algae Through photosynthesis, the algae provides food to the fungi. In turn, the fungi protects the algae cells from dying out because they are able to store large amounts of water for long periods of time.

6. Symbiosis Because of this symbiotic relationship, lichen can be found in a wide range of habitats, including the arctic tundra. Reindeer feed mainly on lichen during the winter. Lichen on WoodLichen on Rocks

7. Symbiotic In a similar fashion, coral is also often thought of as one organism but actually consists of a symbiotic relationship between an algae and an animal. The algae benefit because they have a substrate upon which they can reach the sunlight to photosynthesize and the coral benefit from the oxygen and sugar the algae provide. Symbiodium Algae Coral Not a plant because it cannot make its own food and does not have plants structures but instead has tentacles that they capture food with.

8. Symbiosis There are three different types of symbiotic relationships: MutualismParasitism Commensalism Dung Beetle

9. Mutualism In a mutualistic relationship, both species benefit. While pollinating animals collect nectar, pollen becomes attached to their bodies. When they move to other flowers, the pollen is transferred and pollination occurs. Pollinator benefits from a high energy meal and the plant benefits because it is able to reproduce.

10. Mutualism Bees are not the only pollinators. There are several different types of animals that also help pollinate flowering plants. Butterflies Bats Honey Possums HummingbirdsBeetles Lizards

11. Parasitism In a parasitic relationship, one species is harmed, while the other species benefits. The species that is harmed is called the host and the species that benefits is called the parasite. Parasitic relationships differ from predator-prey relationships in that the parasite usually doesn’t initially kill the host, if it even kills the host at all. Parasite Host Fleas

12. Parasitism Some parasites are carried from one host to another host through another animal, called a vector. Mosquitoes are a common vector. ParasiteVectorHost Elephantitis

13. Parasitism Malaria is caused by a parasitic microscopic organism called a protozoan that uses the mosquitoes and humans to help complete its reproductive cycle. 1.Mosquito injects parasite when it bites the human. 2.Protozoan parasite travels to liver cells and then red blood cells. 3.Another mosquito bites an infected human and ingests the protozoan parasite. 4.Protozoan parasite sexually reproduces in the gut of the mosquito.

14. Commensalism Spanish moss grows on trees to reach sunlight. Because they can photosynthesize its own food, as well as obtain its own moisture and nutrients from the air, it does not harm the trees at all. While the tree is not harmed by the Spanish moss, it also receives no benefit. In a commensalistic relationship, one species benefits while the other species is not affected at all.

15. Competition and Predator-Prey Relationships Two other types of interactions found in ecosystem are competition and predator-prey relationships. Although these relationships involve interactions between different species, they are not as species specific as the symbiotic relationships. CompetitionPredator-Prey

16. Competition Competition between two different species can occur over any resource such as food, water, and space. In the west, they have an open range policy where any and all ranchers can allow their herds of cows to graze freely anywhere on the range. Competition between cows and wild deer arise as more cows are allowed to graze on the range.

17. Competition Competition often occurs between plants. When non-native plants are introduced to an area, they often out-compete the native plants for water, minerals, and space. In the competition relationship, the one who can out-compete the other is the species that benefits. Kudzu

18. Predator-Prey Predator-prey relationships occur when one species, the predator, kills and eats the other species, the prey. Grazers are common prey for carnivorous predators.

19. Predator-Prey The predator-prey relationship is crucial in keeping the ecosystem in balance. Too many grazers results in overgrazing and starvation. Natural predators, keep the number of grazers down. However, too many predators results in overhunting and eventual starvation of predators. As the number of predators decrease, the grazer populations begin to increase again and the cycle repeats itself.

20. The End Nemo’s science question https://www.youtube.com/watch?v=bZ1KDf3O-qU