Plant Animal Interactions Flashcards
define mutualism
both species benefit
define commensalism
one benefits
no impact to other
define predation
one benefits
one loses
define amensalism
one loses
no impact
define competition
neither win/lose
most common species interaction?
plants and animals
what are the 4 types of herbivory?
gazers
browsers
frugivores
granivores
constraints of herbivory in N regions?
short growing season
- constrains plant growth/reproduction
- constrains herbivore growth and repro
heavy exploitation of plant species by herbivores can…
- decrease abundance
- destroy insulating moss layers
- change plant communities
benefits of herbivores?
- defecate, adding nutrients
- alter competition regimes btwn plants
- disperse seeds
costs of herbivory?
complete defoliation
precludes reproduction
muskox impacts on willow
main summer food source
-production of arctic willow +’vely affects muskox next year
vise versa
What are producers limited by?
competition and resources
- not herbivory
define trophic cascade
influence of producers or consumers on species that are 2+ trophic levels away
define top-down control
influence on predators on relative abundance on lower trophic levels
define bottom-up control
influence of producers on relative abundance of higher trophic levels
hypotheses regarding why the world is green
Exploitation ecosystem hypothesis (EEH)
Exploitation ecosystem hypothesis (EEH)
- effects of trophic cascades usually alternate by trophic level
- primary productivity determines the number of trophic levels in an ecosystem
example of a trophic cascade
kelp, sea urchins, and predators in Alaska
what determines the number of trophic levels?
productivity
plant defence traits against herbivory
mechanical (toughness, spines, etc.)
chemical (alkaloids, phenolics, etc)
developmental/phenlogical
types of plant defence based on production
- define
Constitutive: present irrespective of attack (thrones)
Induced: produced in response to the attack
define co-evolution? how may this occur with herbivory?
evolution of 2+ interdependent species, each adapting to changes in the other
plants evolve defences–> herbivores evolve ways to overcome
example of co-evolution (general)
newt develops toxins
predators more resistant will have advantage over predators w/o
only most toxic newts survive
predator evolves more resistance to toxins
specific example of co-evoluation
crossbills and black spruce
-bill morphology and cone morphology
define seed masting
the synchronous and highly variable production of seeds by a population of plants
how does masting impact red squirrel life history response?
large litters
more yearlings breed
more offspring produces
example of secondary plant metabolites
[increase] in Arctic willow during growing season
-more energy, nutrients, and productive investment
example of mutualism within herbivory
minus and Clark’s nutcrcker
- dispersal of seeds through scatter hoarding
why are oviposition sites probably limited in boreal forests?
closed canopies
seasonality
sever cold winters
tree spp mostly conifers (wind pollinated)
are insects important in boreal regions?
previously thought no… more recently YES!
- plants have diversity of pollination strategies
define entomophily
where is this most common?
example
pollination by insects
high arctic
Arctic rose
common pollinators in high arctic
bees mosquitoes moths wasps beetles flies
percentage of bees/insects in NA compared to boreal region
- 3% NA
- 4% Boreal
- mostly bumblebees bc generalists, social (thermoregulate)
What is the most important/abundance pollinator in Sweden?
Diptera
