Community Ecology Chapter 54

Community An assemblage of populations of various species living close enough for potential interactions

Learning Targets I can describe the following interspecific interactions and explain how they impact the community: Competition Competitive exclusionary avoidance through: resource partitioning, fundamental and realized niches, character displacement Predation Predation effects: aposematic coloration, cryptic coloration, Batesian and Mullerian mimicry Herbivory Symbiosis Distinguishing between: parasitic, commensal, mutualistic Facilitation I can quantitatively demonstrate the diversity of a community. I can explain the relationship between community diversity and stability, including the impact keystone and dominant species have on stability. I can describe how disturbance can impact a community. I can explain how ecological succession works I can distinguish between primary and secondary succession I can describe a climax community. I can describe how human and natural disturbances can alter succession.

Types of Interactions Interspecific Interactions Interactions with other species Intraspecific Interactions Interactions within one species

Ecological Niche Every species survives and reproduces utilizing a range of chemical and biological conditions

Competitive Exclusion Principle Direct interspecific competition will always lead to the extinction of one species One species will have a slight competitive edge in surviving and reproducing

Interspecific Species Interactions

Predation (+/-)

Predation Defense Strategies Cryptic coloration – camouflage Aposematic coloration – warning coloration Batesian mimicry – a harmless species mimics a harmful one Mullerian mimicry – two harmful species mimic each other

(a) Cryptic coloration(b) Aposematic coloration Canyon tree frog Poison dart frog (c) Batesian mimicry: A harmless species mimics a harmful one.(d) Müllerian mimicry: Two unpalatable species mimic each other. Hawkmoth Larva (harmless) Cuckoo bee Yellow jacket Green parrot snake (harmful)

Herbivory (+/-)

Parasitism (+/-)

Commensalism Commensalism (+/0)

Mutualism Mutualism (+/+)

Facilitation (+/+ or 0/+) One species influences the survival and reproduction of another species Ex: plant species that make soil hospitable for other species to thrive

Learning Targets I can describe the following interspecific interactions and explain how they impact the community: Competition Competitive exclusionary avoidance through: resource partitioning, fundamental and realized niches, character displacement Predation Predation effects: aposematic coloration, cryptic coloration, Batesian and Mullerian mimicry Herbivory Symbiosis Distinguishing between: parasitic, commensal, mutualistic Facilitation I can quantitatively demonstrate the diversity of a community. I can explain the relationship between community diversity and stability, including the impact keystone and dominant species have on stability. I can describe how disturbance can impact a community. I can explain how ecological succession works I can distinguish between primary and secondary succession I can describe a climax community. I can describe how human and natural disturbances can alter succession.

Species Diversity Species richness: Total amount of species in a community Relative abundance: Total amount of one species in a community Diversity is key to a healthy, stable ecosystem

Learning Targets I can describe the following interspecific interactions and explain how they impact the community: Competition Competitive exclusionary avoidance through: resource partitioning, fundamental and realized niches, character displacement Predation Predation effects: aposematic coloration, cryptic coloration, Batesian and Mullerian mimicry Herbivory Symbiosis Distinguishing between: parasitic, commensal, mutualistic Facilitation I can quantitatively demonstrate the diversity of a community. I can explain the relationship between community diversity and stability, including the impact keystone and dominant species have on stability. I can describe how disturbance can impact a community. I can explain how ecological succession works I can distinguish between primary and secondary succession I can describe a climax community. I can describe how human and natural disturbances can alter succession.

Keystone Species Organism with a pivotal role in an ecosystem The removal of a keystone species results in the collapse of the ecosystem Ex: sea otter (Enhydra lutris)

Learning Targets I can describe the following interspecific interactions and explain how they impact the community: Competition Competitive exclusionary avoidance through: resource partitioning, fundamental and realized niches, character displacement Predation Predation effects: aposematic coloration, cryptic coloration, Batesian and Mullerian mimicry Herbivory Symbiosis Distinguishing between: parasitic, commensal, mutualistic Facilitation I can quantitatively demonstrate the diversity of a community. I can explain the relationship between community diversity and stability, including the impact keystone and dominant species have on stability. I can describe how disturbance can impact a community. I can explain how ecological succession works. I can distinguish between primary and secondary succession. I can describe a climax community. I can describe how human and natural disturbances can alter succession.

Disturbance & Succession Disturbance – event that changes the dynamics of a community Succession – recovery of that community after a disturbance

Primary vs. Secondary Succession Primary – begins with rock Ex: glacier, volcano Secondary – begins with soil Ex: forest fire, flood Climax community – recovered, long term stability

Learning Targets I can describe the following interspecific interactions and explain how they impact the community: Competition Competitive exclusionary avoidance through: resource partitioning, fundamental and realized niches, character displacement Predation Predation effects: aposematic coloration, cryptic coloration, Batesian and Mullerian mimicry Herbivory Symbiosis Distinguishing between: parasitic, commensal, mutualistic Facilitation I can quantitatively demonstrate the diversity of a community. I can explain the relationship between community diversity and stability, including the impact keystone and dominant species have on stability. I can describe how disturbance can impact a community. I can explain how ecological succession works I can distinguish between primary and secondary succession I can describe a climax community. I can describe how human and natural disturbances can alter succession.

Human vs. Natural Disturbance Humans – clearing land for own uses Ex: logging, agriculture Generally, no recovery to climax community