lecture 7 notes from prof. Thomson

26 views6 pages
Published on 12 Nov 2011
School
Department
Course
Professor
Lecture 7: Species interactions: From 2-species population models to community structure
Types of interaction classified by who pays and who benefits
Consumer-resource (+/-, Ricklefs treats first)
o Predator-prey
o Plant-herbivore
o Host-parasite
Competition (-/-, I treat first)
Mutualism (+/+)
Lotka-Volterra equations
intraspecific competition: competition between individuals of same species
interspecific competition: competition between individuals of different species
Outcomes of L-V competition
The two species may stably coexist
o Coexistence requires both species to inhibit their own growth more than they
inhibit each other’s
Species 1 may always win (N1 = K1, N2 = 0)
o Can expand to consider n species
Species 2 may always win (N2 = K2, N1 = 0)
Identity of winner may depend on starting N’s.
Unlock document

This preview shows pages 1-2 of the document.
Unlock all 6 pages and 3 million more documents.

Already have an account? Log in
Law of Competitive Exclusion
Stated that two species cannot coexist indefinitely when the same resource limits both
species (两个吃同样食物的物种不能共存)
o ONLY TRUE for math model, COEXIST DO EXIST in nature!!!!
Experiments by Gause
Experiment with protozoa.
Depends on species, he can get
both stable coexist, and
competitive exclusion.
In reality..
Competitve exclusion is less likely to go extinction
o Species can hide in different places
o Biological effects interact with physical effects.
o Natural selection favors better competitors
Experiment by Tensely
G.sylvestre grows better in base soil
G. saxatile grows better in acid soil
When the two put together, sylvestre
wins saxatile in base soil, saxatile wins
sylvestre in base soil.
Unlock document

This preview shows pages 1-2 of the document.
Unlock all 6 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Lecture 7: species interactions: from 2-species population models to community structure. Types of interaction classified by who pays and who benefits. Consumer-resource (+/-, ricklefs treats first: predator-prey, plant-herbivore, host-parasite. Lotka-volterra equations intraspecific competition: competition between individuals of same species interspecific competition: competition between individuals of different species. The two species may stably coexist: coexistence requires both species to inhibit their own growth more than they inhibit each other"s. Species 1 may always win (n1 = k1, n2 = 0: can expand to consider n species. Species 2 may always win (n2 = k2, n1 = 0) Identity of winner may depend on starting n"s. Stated that two species cannot coexist indefinitely when the same resource limits both species ( : only true for math model, coexist do exist in nature!!! Depends on species, he can get both stable coexist, and competitive exclusion.

Get OneClass Grade+

Unlimited access to all notes and study guides.

YearlyMost Popular
75% OFF
$9.98/m
Monthly
$39.98/m
Single doc
$39.98

or

You will be charged $119.76 upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.