Ecology Part 2 (Community Study)

Front 1

What is a community?
What is a niche?
Where do they occupy?

Back 1

The key to understanding the ecological community is study of interspecific interactions

Communities occupy habitats (the place occupied by a habitat)

A niche is the ecological role (like a job) of a species in a community.

Front 2

Structure In Communities

Back 2

-Many communities are dominated by only a few species (Ecological Dominants
-Communities are named on in terms of their dominant species
(Redwood Forest, Oak Woodland Community)

Front 3

Keystone Species

Back 3

-They are central to community stability
-Keystone species are often predators, particularly top predators

Front 4

Species Richness

Back 4

-Species Richness is simply the total number of different species that live within the community


Biodiversity, in contrast takes three primary forms
-A richness of species in a given area

-A geographic distribution of species populations (where they can be found)

-Genetic diversity within gene pool (the extent of their gene pool)

Front 5

Biodiversity

Back 5

Biodiversity, in contrast takes three primary forms
-A richness of species in a given area

-A geographic distribution of species populations (where they can be found)

-Genetic diversity within gene pool (the extent of their gene pool)

Front 6

High Biodiversity

Back 6

A. Many different species (Species Richness)
B. Broad Distribution of species
C. High genetic diversity

Front 7

Species Diversity is the Measure of?
What might a drop in species diversity be contributed to?

Back 7

-Species diversity is seen as a measure of the overall health and stability of a community. Drop in species diversity is bad


A drop in diversity may be the result of a :
-loss of keystone species, ,
-the introduction of some kind of pollutant
-damage to the habitat
-or the introduction of a invasive, non-native species.

Front 8

Modes of Interaction (What symbols mean)

Back 8

"-" Indicates harm to the species from the interaction

"+" iindicates a benefit to the species

"0" neutral, neither species is harmed nor benefited

Front 9

8 Types of Interaction (Overview)

Back 9

Competition (-/-)
Predation (+/-)
Parasitism (+/-)
Parasitoidism (+/-)
Mutualism (+/+)
Commensalism (+/0)
Amensalism (-/0)
Neutralism (0/0)

Front 10

(Competition -/-)

Competition involves competitors
What is competition?
What is the denotation for Competition?
What are the types of competition?
What does competition limit?

Back 10

-/-

-Competition involves competition of resources between species
-Mode of interaction
-Species compete for resources
-Limits population growth

Direct Competition
-When the species come into direct contant

Indirect Competition
-When the species fight over a kill

Front 11

(Competition -/-)
What is competitive exclusion?

Back 11

When two species are not equally matched
-When one species (competitor) drives another species (competitor out)

Front 12

(Competition -/-)
How do we reduce Niche Overlap, how do competitors coexist?
(Response to Competition)

Back 12

-We reduce niche overlap through resource partioning(niche partioning)

-Where are organisms take a resource area and partition it
-This minimizes competition, and role overlap.
-Occurs through natural selection

Front 13

(Competition -/-)
Character Displacements (Response to Competition)

Back 13

-Another competition reducing mechanism

-Due to limited resources

Front 14

(Predator/Prey +/-)
What is predation?

Back 14

-Predation is a mode of interaction where on species benefits and one is harmed

-Predators do not wipe out all their prey

Front 15

(Predator/Prey +/-)
Short term solutions : Prey

Back 15

Prey Refuge : A place they can go to seek sanctuary from predators

Front 16

(Predator/Prey +/-)
Short term solutions : Predator

Back 16

-Predators do not wipe out their prey
-Resource Shifting : Predators cant find main resources, so they switch

-Patch foraging : Predators will go to patch(area of habitat) that has more prey, prey also recover since predator leaves

Front 17

(Predator/Prey +/-)
Long term evolutionary solutions : Predator

Back 17

-Predators may evolve to become larger
-Predators may evolve to cooperatively hunt (pack of wolves)

Front 18

(Predator/Prey +/-)
Long term evolutionary solutions : Prey

Back 18

-Prey may evolve to become larger
-Prey form herd for mutual protection

Front 19

(Predator/Prey +/-)
Long term evolutionary solutions : Prey
(CRYPSIS)

Back 19

Crypsis : Becoming less detectable
-Camouflage
-Backround or Color matching

Mimicry
-Involves a species evolving to look like another species
-Key players are mimic, and model
-Aposematic are warning colors

Front 20

Parasitism and Parasitoidism +/-
What are these modes of interaction varieties of?
What kind of Parasites are there (inside vs outside)

In parasitism what have many species evolved to do?

Back 20

-Both are forms of predation
-In parasitism many species have evolved to transfer from different hosts as they mature and prepare for the final destination of reproduction in the "ultimate host"

-Parasites who live in host :Endoparasites
-Parasites who live outside of host :Ectoparasites

Front 21

(Mutualism +/+)

Back 21

-Mutualism is an interaction between individuals of different species that is beneficial to both
-Regarded as to partners
-Sometimes relationships are so tight that if one partner perishes, so will the other

Front 22

(Commensalism (+/0)

Back 22

Commensalism is an interaction in which an individual from one species benefits while an individual from another species is neither harmed nor helped.

A bird using a tree in which to build its nest would be considered a commensalistic relationship. The bird benefits from the tree, but the tree neither benefits or is harmed by the bird.

Front 23

Amensalism (-/0)

Back 23

In amensalism, one species is harmed by the relationship but the other is neither harmed or benefited (think of stepping on ant). This is -/0

Front 24

Neutralism 0/0

Back 24

In neutralism, two species in a community have absolutely not relationship with each other (0/0). This may be silly, but this non-relationship should be the rarest of them all (no relationship of any type at any time?)

Front 25

Coevolution

Back 25

-When species evolve interdependetly of each other
-Flowers evolve to attract bees, bees evolve to see pollen in flowers

Front 26

Succession
(How a community is formed)

Back 26

Parcels of land or water that have been abandoned by humans or devastated by physical forces will almost always be reclaimed by nature to some degree.

-Takes a very long time
-Each step in succesion is called a sere
-The final sere, is the climax community

-

Front 27

Types of Succesion : Primary
(How a community is formed)

Back 27

Primary succession proceeds from -state of little or no life,
-soil that lacks nutrients.
This is the case the formation of geological features such as islands

Front 28

Types of Succession : Secondary

Back 28

Proceeds a disturbance, either human induced or naturally induced