Chapter 10 Flashcards
Army ants
- Live in swarms
- Make a nest out of ant bodies (bivuoac)
- Eusocial animals
- Bivuac moves every 2–3 nights
- Hunting: They spread out and eat anything they can find
- can kill animals much larger than them
Ant birds
- Live anywhere where army ants swarm
- Eats the “sloppy seconds” of the ants
- Each adapted to be a part of the community of aunt birds
- They organize themselves around the ants around the swarm
- each has a designated spot so they don’t outcompete eachother
Communuity
- A group of organisms that live together at the same place at the same time and interact directly or indirectly.
Includes all organisms present: animals, plants, fungi, bacteria
Forest communities
Community organization
- Changes in environmental factors (environmental gradients) correspond with community changes.
- transition zones between communities are called ecotones
Community unit concept
- Proposed by Frederick Clements
- Community is highly organized, made up of multiple co-adapted species
- All the animals are a unit and these communities evolve together
ex. ant birds co-adapting to army ants
Continuum concept
- Henry Gleason
-Communities are just a coincidence - Organisms just happen to need the same elements to survive and that’s what brings them together
- Organisms are “just in it for themselves”
Clements vs Gleason
Clements unit predicts: discreet community types with sharp eco tones
Gleason’s continuum predicts: continuous variation
Gleason is right: There are continuous non-discreet distribution patterns along gradients of environmental factors
Why is Clement’s theory useful even if it’s kinda wrong?
- Its helpful for explanations
- Discrete community units are important in areas like forestry
what are 3 ways comunities can be studied?
- Communities can also be organized by the functional role species play
- Communities can be studied based on trophic position (autotrophs, herbivores, carnivores, detrivors)
or
-by the way organism use resorces
Guild
Group of organisms that use similar resources
ex. Bats hummingbirds insects all feed on nectar and are in the floral visiting guild
Organisms not related but united by their need for similar resources exstracted in the same way
What types of interactions are there?
- Herbivory
- predation
- Competition
- Disease
- Symbiosis
- Mutualism
- Parasitism
-Commensalism
Herbivory
- Herbivorous are numerous on the bottom of the trophic pyramid
- They can have major influences on community composition
ex. Spruce budworm kills trees - can completely change an ecosystem
Predation
Reduce herbivore population, which can lead to increased plant growth.
ex. Bay breasted warbler who eats spruce budworm
Competition
- Resources are finite
- Animals compete for food territory nesting location
Competitive ability can influence species presents and abundance
