Species Interactions and Community Ecology. Chapter 6. Species interactions. Species interact in several fundamental ways. Species interactions. When multiple species seek the same limited resource Interspecific competition is between two or more species.
Species interact in several fundamental ways.
When multiple species seek the same limited resource
Usually does not involve active fighting, but subtle contests to procure resources.
Coexisting competitors may adjust their resource use, habitat use, or way of life to minimize conflict.
Adjusting resource use, habitat use, or way of life over evolutionary time leads to:
Tree-climbing bird species exploit insect resources in different ways.
One species, the predator, hunts, kills, and consumes the other, its prey.
Population dynamics of predator–prey systems sometimes show paired cycles: ups and downs in one, drive ups and downs in the other.
(here, caterpillar mimics snake)
Camouflage to hide from predators
Bright colors warn that prey is toxic
One species, the parasite, exploits the other species, the host, gaining benefits and doing harm.
One of the most common types of exploitation is herbivory, which occurs when animals feed on the tissues of plants.
Both species benefit one another.
Hummingbird pollinates flower while gaining nectar for itself.
Together, these comprise trophic levels:
We can represent feeding interactions (and thus energy transfer) in a community:
A “keystone” holds an arch together.
When the keystone sea otter is removed, sea urchins overgraze kelp and destroy the kelp forest community.
A series of regular, predictable, quantifiable changes through which communities go
• Primary succession: Pioneer species colonize a newly exposed area (lava flows, glacial retreat, dried lake bed).
• Secondary succession:The community changes following a disturbance (fire, hurricane, logging).
1. Open pond
2. Plants begin to cover surface; sediment deposited
3. Pond filled by sediment; vegetation grows over site
As altitude increases, vegetation changes in ways analogous to changes in latitude.
Which of the following lists of trophic levels is in the correct order?
a. Producer, secondary consumer, herbivore
b. Producer, herbivore, secondary consumer
c. Secondary consumer, producer, detritivore
d. Herbivore, carnivore, producer
Primary succession would take place on all of the following EXCEPT…?
a. The slopes of a Hawaiian volcano’s new lava flow
b. A South Carolina coastal forest after a hurricane
c. Alaskan land just uncovered as a glacier melts
d. A new island formed by falling levels of a reservoir in Ohio
Which biome has warm stable temperatures, highly seasonal rainfall, deciduous trees, and high biodiversity?
a. Tropical rainforest
b. Tropical dry forest
c. Temperate rainforest
What would you recommend as the primary approach to dealing with invasive species in a bay area with heavy maritime trade, and why?
a. Establish tough restrictions with trading partners
b. Use chemical treatments, barriers, and removal
c. Use biological control
d. Some combination of the above (describe)
What does the graph illustrate?
a. Paired predator–prey cycle
b. Competitor exclusion
c. Resource partitioning
In this climatograph for Los Angeles, California, in the chaparral biome, summers are… ?
a. Warm and dry
b. Warm and wet
c. Mild and dry
d. Mild and wet
A celebrity made headlines when she illegally brought an apple into the U.S. from abroad. How far should governments go to prevent invasive species?
a.As far as they can; preventing invasive species is worth the expense and inconvenience of strict regulations.
b. Governments need to be reasonable in allowing for important activities (e.g., ship movement).
c. The threat of invasive species is vastly overrated, and governments should focus on more important priorities.