Download Includes interspecific interactions

Chapter 54 Community Ecology
-Community Interactions are classified by whether they are
harmful, helpful, or have no effect
-Dominant or Keystone species exert control over whole
community
-Disturbance influences species diversity and composition
-Biogeographic factorsaffect community biodiversity
How many interactions between species can you
see in this picture?
A community is the sum of all local overlapping/nonoverlapping niches
-Includes interspecific interactions
1. Interspecific Competition (-/-) can lead to the competitive exclusion
principle or one species will out compete another and can lead to character
displacement
Fundimental Niche – Niche a species could have
Realized Niche – Portion of the Fundimental Niche a species lives in
2. Predation (+/-)
3. Herbivory (+/-)
4. Symbiosis ----- Parasitism (+/-), Mutualism (+/+), or Commensalism (+/=)
Which community is more diverse? (Community 1)
1. Abundance
2. Richness
Trophic Structure of a Community:
Plays a large role in community dynamics
1. Food Chains
2. Food Webs
Types of Species that can control an ecosystem
1. Dominant = Most Biomass in the ecosystem
2. Keystone = Organism that controls the diversity
of a ecosystem by its unique niche (p. 1208)
3. Foundation = An organism that changes the
physical nature of an ecosystem due to its unique
niche (Beaver Dams)
What organism controls
the dynamics of an
ecosystem?
P = Predators
V = Plants
H = Herbivores
N = Nutrients
Top Down
(Predator controlled )
P–H–V–N
Bottom Up
(Nutrient Controlled)
N–V–H–P
Disturbances that
influence the physical
nature of an ecosystem
1.
Fire (Natural Process)
2.
Storm
3.
Drought
4.
Flood
5.
Human Disturbance
Stage 1
Stage 4
Stages of Succession
after a disturbance
Stage 2
Stage 3
Biogeographic factors that
influence an ecosystem.
1.
Latitude – Tropical Areas are generally more diverse due to moderate temperatures and
higher precipitation
2.
Size of the environment – The bigger the environment the more species and diversity
3.
Island Biogeography – Isolation, and the equilibrium model