Lec12_08BIEB102

Lec12_08BIEB102 - BIEB 102 Lecture 12: interspecific...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: BIEB 102 Lecture 12: interspecific competition I. Overview II. Types of resources III. Models of interspecific competition IV. Competition experiments involving plants V. Competition experiments involving animals VI. Interactions between competition and predation I. Overview Competition is any use or defense of a resource by one individual that reduces the availability of that resource to other individuals. Competition can decrease population growth rates. Increasing population size can lead to shortages in food and other limiting resources intraspecific aggression These factors can act to lower birth rates to elevate death rates Ricklefs Figure 19.7 I. Overview Interspecifc competition between individuals of different species causes a mutually depressing effect on the populations of both. If strong enough, interspecific competition can lead to the exclusion of species from a local site. Ricklefs Figure 19.8 I. Overview Two main types of competition Exploitative: individuals compete indirectly through their mutual effects on shared resources Interference: competitors acting directly through antagonistic behaviors. Common when resources can be profitably defended. Effects can reduce exploitative ability of competitor Ricklefs Figure 19.13 II. Types of resources Resource: any substance or factor that is consumed by an organism (reducing its availability to others) supports increased population growth rates as its availability increases Food is a common limiting resource. Water can be a limiting resource for terrestrial organisms. But consumption is more than just eating & drinking. Space is consumed by sessile organisms. Refuges are consumed by mobile organisms. II. Types of resources Resources can be classified by how consumers affect them. Nonrenewable resources are not regenerated (but can be recycled). e.g., space only becomes available when a consumer dies or leaves Renewable resources are constantly regenerated (e.g., births in a prey population) (1) Source external to the system, e.g., sunlight, precipitation (2) Source within system, e.g., prey for a predator III. Models of competition GF Gause pioneered experimental studies of competition in the lab. Competitive exclusion is common in such lab experiments. Competitive exclusion principle: two species cannot coexist indefinitely on the same type of limiting resource. What factors promote coexistence in nature? Ricklefs Figure 19.6 III. Models of competition The theory of competition is an extension of logistic growth models Lotka, Volterra & Gause were important contributors to this theory. For interspecific competition, populations of 2 species must be considered Intraspecifc Competition Intraspecifc + Interspecific Competition dN 1 /dt = r 1 N 1 ((K 1- N 1 )/K 1 ) dN 1 /dt = r 1 N 1 ((K 1- N 1- 12 N 2 )/K 1 ) dN 2 /dt = r 2 N 2 ((K 2- N 2 )/K 2 ) dN 2 /dt = r 2 N 2 ((K 2- N 2 - 21 N 1 )/K 2 ) III. Models of competition dN 1 /dt = r 1 N 1 ((K 1...
View Full Document

Page1 / 40

Lec12_08BIEB102 - BIEB 102 Lecture 12: interspecific...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online