Class Notes (786,277)
Canada (482,090)
Biology (2,220)
BIO220H1 (238)
Lecture 16

Lecture 16 Ecological Consequences of Genetic Variation
Lecture 16 Ecological Consequences of Genetic Variation

3 Pages
Unlock Document

University of Toronto St. George
Doug Thomson

Lecture 16 BIO220 Ecological Consequences of Genetic Variation Biodiversity  resistance to perturbation, increased productivity e.g. High species richness, high biomass after drought Are plant patches that are more genetically diverse able to support more insects? • Grow groups of monocultures (only 1 genotype), or polycultures (mixture) • Measure # and identify herbivores, omnivores, predators Result: more genetically diverse plant communities support more predatory insects. Increased number of genotypes, predator richness Mechanism: • Genotypes in mixture react additively o Genotypes independent o Predator abundance on a genotype in monoculture = abundance on that genotype in polyculture o Communities: whole is sum of parts • Genotypes in mixture react non-additively o Properties of genotype depend on other surrounding genotypes o Abundance of predators on genotype in monoculture do not predict that in polyculture o Communities: whole is > or < than sum of parts Whole > sum of parts • Plant genotypes differ in nutritional qualities, growth, defensive compounds, flowering phonologies • More diverse patches, more spatial, temporal niches for insects • Once insects find a patch, they may be more likely to stay and visit other nearby genotypes Polycultures recover from severe disturbances faster, are more resilient to natural disturbance Mechanism: • Polycultures: more tolerant genotypes, can regrow quickly • Overperformance of polycultures: interaction between genotypes o Different resource uptake strategies of genotypes o More micro-niches, less competition Galled plants decompose slower, have greater retention of C/N compared to ungalled. Genetic variation affects nutrition cycling • Chain of causation o Genotypes differ in chemical properties o Different attack by insects o Genotypes differ in chemical responses to attack o Combined set of chemical differences alter decomposition, nutrition cycling Coyote Bush • Facilitates colonization of other species • 2 distinct genotypes: affect light, temperature, litter depth, which affect biomass, % cover, species richness of colonizers o erect • Tall, more light, low litter depth, hotter • More biomass, % cover, species richness o Prostrate • Short, Low light, High litter depth, Low Temperature Genotypes differ in architecture  alt
More Less

Related notes for BIO220H1

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.