Gen Eco: Chapter 18

Define Mutualism

-An interaction between two species in which each species receives benefits from the other

Define Generalist Mutualist

-A species that interacts with many other species

Define Specialists Mutualists

-A species that interacts with one other species or a few closely related species

Define Obligate Mutualism

-Two species that provides fitness benefits to each other and require each other to persist

Define Facultative Mutualism

-Two species that provide fitness benefits to each other, but the interaction is not critical to the persistence of either species

Give examples of Obligate Mutualism for acquiring resources

Tubeworms and Chemosynthetic Bacteria: -Bacteria live in worms, worms get food from bacteria bc bacteria synthesizes

-Without each other, they would die

Coral and Zooxanthellae: -Corals catch food with tentacles that emit CO2 and Algae uses that CO2 for photosynthesis

-Coral consumes sugars, oxygen is produced by Algae

-If algae is expelled, they die 

Give examples of Facultative Mutualism for acquiring resources

Clownfish and Sea Anemones: -Clowfish could live without the Anemones

-Sea Anemonies may or may not be abe to live depending if they can get food somewhere else

-This is a weird example

Aphids and Ants: -Aphids suck up sap from plants and produce droplets that the Ants eat 

-Ants protect Aphids from predators

-Both benefits but can survive without each other 

Define Mycorrhizal Fungi

-Fungi that surrounds plant roots and help plants obtain water and minerals

Define Endomycorrhizal 

-Hyphae threads from fungi penetrates soil to get nutrients, other parts goes between cell wall and cell membrane into the root

-Enters cells 

-Seen in variety of plants 

Define Ectomycorrihizal

-Hyphae surrounds roots and goes in between cells

-Does not enter cells

-Seen in trees and shrubs

Define Arbuscular Mycorrhizal Fungi

-Type of Endomycorrhizal Fungi

-Helps fungus provide nutrients to plants

-Infects number of plants (apple trees, peach trees, coffee trees, grasses)

Explain how Mutualists aid in animals acquiring resources and give examples

-Aphid Shrimp burrows in ocean floor and shares currow with Gobie

-Gobie (Good vision) helps the Shrimp (Bad vision) warning shrimp of incoming predators

-Honey Guide Birds consume bee larva and wax but has hard time getting into hive, Humans have a hard time finding the Hive for honey 

-Humans follow Bird to hive then break open hive for bird

-Both Benefits 

Explain how mutualistic aid in defenses for plants

-Endophytic Fungi

-Helps defend plants and provide drought resistance by increasing plant tissue mineral concentration

-Lives inside plant tissues

-Produces chemicals that repel herbivores

Explain how mutualistic aid in defenses for Animals

Ox Pectors and Grazers: -Ox Pector sits on back of grazers and consume ticks that are attached to Grazers

Cleaner Wrasse: -Cleaner Wrasse consumes ectoparasites that are attached to larger fish

-Both Benefits

Explain how mutualistic aid in defenses for Both Plant and Animal Example 

-Acacia Trees has lots of plant competitors 

-Ants make nests in thorns of trees and receives shelter/nectar from tree

-Tree receives defense from herbivores and protection from other plants/competitors 

-Tree with Ants have higher survivorship than Tree without Ants 

Explain how mutualists can facilitate pollination

-Pollen get attached to organisms as they consume the nectar 

-Certain flowers are designed specifically for a long beak and tongues 

-Some plants only open at night for pollination for bats 

Explain how mutualists can facilitate seed dispersal

Elephants: -Elephants eat fruits, seeds are consumed

-Seeds cannot germinate until passed through Elephants gut

-Elephants help disperse seeds

Ants: -Some plants entice animals to disperse their seeds by having a fruit full of nutrients around seeds

-Ants disperse seeds by taking them underground where the seed can start growing

-Seed is covered by lipids and proteins for the Ants

What are mutualists for seed dispersal and pollination called

-Ecosystem Services

Explain how mutualists affect species diversity 

-Cleaner Wrasse helps fish species persist, bc of this we have greater diversity

-Removing Cleaner Wrasse causes a number of larger fish species to decline and diversity is reduced 

Explain how mutualists affect Species Distribution

-Plant abundance can be reduced by the loss of dispersers

-As dispersers decline, plant abundance declines

-Researchers brought in Nonnative Torts to help disperse the seeds, we saw increase in abundance in the declining tree species

Explain how mutualists affect Ecosystems Functions

Ants: -Used as defense against grazers and other plants in Acacia Trees

-In return, the Ants get to live in the trees

Experiment: -In individual plants that were fenced off from Mammals, they had fewer swollen thorns = less Ants bc they dont have to worry about mammals grazing

-Individuals that weren’t fenced from Mammals had more swollen thorns = More ants to protect the trees

Grasslands: -Grasslands that have more fungal species took up more phosphorus and plants had greater biomass in that ecosystem than other ecosystems