ch 17 Flashcards
(51 cards)
Coevolution
back-and-forth evolutionary adjustments of interacting species in an ecosystem.
Secondary Compounds
chemicals some plants make for protection.
ways that two species can interact
predation
competition
symbiosis
predation
one species feeds on another
competition
when two species use the same resource.
symbiosis
two or more species living in close long-term association
types of symbiosis
mutualism
commensalism
parasitism
mutualism
both species benefit
commensalism
one species benefits, the other is not harmed or helped
parasitism
type of predation where one species feeds on and lives on or in another (does not kill host but host is harmed).
ants and aphids
mutualistic relationship. Ants get honeydew and aphids get transport to feeding grounds and protected.
exclusive mutualistic relationship
reduces competition
leafcutter ants relationships
Predation relationship with plants - ants prey on plants, plants have loose leaves
Mutualistic relationship between ants and fungi; Ants get proteins and sugars made by fungi. Fungi get food - leaves delivered AND prepared (mulched) by ants.
Competition with mold - both compete for fungi
Mutualistic relationship between Ants and bacteria. Ants get antibiotic protection for their garden from the mold (“bad” fungi), the bacteria may get nourishment from ant exocrine gland secretions and moved to mold that they eat.
niche
how a species lives or functions in an ecosystem
fundamental niche
total niche in an ecosystem that a species is potentially able to occupy
realized niche
actual part of the fundamental niche a species occupies
character displacement
evolutionary adjustment to decrease competition - increased differences between two species or groups, where their niche overlaps. The less alike they are, the less they will compete.
competitive exclusion
local elimination of one or more competing species.
Gause’s Principle of Competitive Exclusion
in competing species, the species to succeed is the one that uses resources more efficiently.
starfish keystone species
preys on mussels which can outcompete other species and make coastal tidal ecosystems less-diverse and more vulnerable to change.
sea otter keystone species
preys of Urchins which eat Kelp forest which provide food and homes for other species and keep coastal tidal ecosystems diverse and less vulnerable to change.
keystone species
a species in which a habitant could not survive without
Predation can lessen the effect of competition enabling greater species diversity
Disturbance dependent ecosystem - Fire and Buffalo
In prairie ecosystems, tall grasses are dominant and will be make up the major producer portion of the climax community. When tall grasses dominate, there is less broadleaf plants (which have more and different seeds as well as flowers), less broadleaf plant eaters, less eaters of broadleaf plant seeds and flower nectar (less diversity). Fire, and then Buffalo, enable more diversity:
- Fire gets rid of tall grass dominators.
- All plant seeds start to grow.
- A limited variety of tall grass would soon dominate except……
- Buffalo like the young grass shoots and eat them exclusively so that….
- A wide variety of broadleaf seed plants take hold and grow
- Because there are now a wide variety of seed plant attracts a wide variety of seed plant eaters so……
- Because there are now a wide variety of seed plants eaters, there are a wide variety of seed plant eaters eaters …..MORE DIVERSITY
more diversity
in ecosystems allows them to be less vulnerable to any change that might come along. Differences in some organisms might allow them to survive and carry on.
