BIO220 Lecture 18 Flashcards
Ecological consequences of genetic variation
Biodiversity results in resistance to…. and higher…
environmental disturbances;
productivity
GUILDS
variety of plant strategies (different types of plants: grass, legumes, etc.)
more biodiversity vs. drought
plants with more biodiversity before drought hit maintained 1/2 their biomass after. Those with low biodiversity only had 1/16 or less biomass after.
Cedar Creek experiement
- planted diff number of species/functional groups in each square on a large field
- test response of squares with more species vs. less species
Results of Cedar Creek experiment
- plants with more biodiversity before drought survived better after drought
- plants with more guilds in 1 square had highest biomass
Cedar Creek experiment aimed to measure…
species diversity
MONOCULTURE
all genotype in the culture/crop is the same
POLYCULTURE
mixture of 4 genotypes or 8 genotypes
What experiment was performed at U of T’s Koffler Scientific Reserve?
Are plant patches that are more genetically diverse able to support more insects?
Are plant patches that are more genetically diverse able to support more insects?
Yes
1 genotype < 4 genotypes < 8 genotypes
*NB: overall number of individuals measured was controlled for
What does it mean if genotypes in a mixture react additively?
- genotypes are independent (no interaction of genotypes w/ surrounding genotypes)
- sum of monoculture results = polyculture results
What does it mean if genotypes in a mixture react non-additively?
- genotypes are dependent on surrounding genotypes
- sum of monoculture results != polyculture results
did the genotypes in the plant-predator study react additively or non-additively?
for 2/3 guilds of insects, it was non-additive
- predators = non-additive; more than expected
- omnivores = non additive; more than expected
- herbivores = additive
why were there more insect guilds than expected?
whole > sum of the parts
- plant genotypes differ in their phenotypes: nutrition, growth, defense, flowering
- more diverse patches = more spacial & temporal niches for insects
- insects more likely to visit nearby phenotypes if they find their preferred phenotype in a mixed patch
what is the suspected cause of hayfever? what is the real cause?
suspected: Solidago (goldenrod)
actual: ragweed
Solidago / goldenrod:
- __ species in 2 generations
- one of eastern N. America’s ___
- colonizes in ____
- 130
- most abundant wildflowers
- abandoned fields
what do goldenrods infected by R. solidaginis have (phenotype)?
gall on the plant (spiky ball thing)
what do R. solidaginis do to plants?
eat plant tissue from the inside, and lay egg inside
Goldenrod genotypes differ in their susceptibility to __
galling
nutrient concentration in galled vs. ungalled plants
galled: more N and C rich
whether or not goldenrods are attacked by insects affect…
rate of nutrient flow in the ecosystem
can genetic variation affect nutrient sampling? give an example.
Yes;
Goldenrod gall formation
rate of decomposition in galled vs. ungalled goldenrods
gall lose nutrients slower, but by 24 weeks, galled = ungalled
Coyote Bush is native to…
California