Succession Flashcards
Most common type of defense
Chemical defense
- after capture
- toxic chemicals (especially beetles)
Types of fighting defense
- stinging (especially wasps)
- after capture
- biting
- kicking
types of crypsis defense
- camo (especially caterpillars)
effects of herbivory on plants
- loss of competitive ability
- defoliation
- go for young leaves, less lignin, more nutrients
- growth rate of plant reduced by up to 25%
Antibrowsing compounds
- alcohols
- alkaloids
- quinones
- glycosides
- flavenoids
- raphides
Plant defenses
- Chemical
2. Structural defenses (spines/thornes) devils club?
Plant chemical defenses
- unpleasant odour
- neurotoxins
- contact irritation
- bitter taste
- proteinase inhibitors
- growth hormone mimics
- psychotropic effects
unpleasant odour example
mustard
contact irritation example
poison ivy
- contact dermatitis
bitter taste example (name the compounds)
lot of berries when they are not ripe
- tannins, alkaloids
neurotoxins
Dinoflagellates and U-tree berries
- dinoflagellates - do not hurt fish but would kill birds
- U-tree berries, kill mammals but not birds and mice. Seeds don’t get metabolized
Proteinase inhibitors
Cotton, chickpea, potato
- inhibit the metabolism of these, they don’t get broken down and animal will starve to death
Growth hormone mimic
cat nip
- mimics the moulting hormone if animal eats this, moults too early/late and die
Psychotropic effects
Peyote (mescaline)
- antibrowing to kangaroo rats, flips out when they eat it
Caffeine
- when spiders have caffeine or mescaline, they suck at making webs
Flower and Bee study
- caffeine is a stimulant at low lvls for bees
- some flowers put small amounts of caffeine in their tubes to increase pollination
- bees more likely to come back
Animal defenses against plant chemical defenses
- mixed function oxidase - oxidation, hydrolysis, reduction
- concentration of toxins
- selective browsing
Concentration of toxins
- take toxins out of leaves they eat, metabolize this toxin to the brightest part of animal
(clams - black part = neurotoxins) - frog
- ants innoculate toxic leaves with fungus.. ants eat the fungus.. they have resistance to the poison… fungus concentrates the poison
Selective browsing
- insects don’t eat the vessels they won’t die
- saliva of moose has antifungal proterties. Reduced growth and toxin production
Ecological Succession
the sequential change in species composition of the community over time
Primary succession
establishment of plant and animal communities in a place where there is nothing
- ex. mount st. helens
What was the first species to colonize bear rock
alder
- because they are nitrogen fixing. have the capacity to utilize atmospheric nitrogen and fix itself into bear rock
Secondary succession
the change of an established community
- eg. when a pond disappears
seral stage
- each sequential community, takes place in secondary succession
- each stage will last longer and longer
how to determine the history of vegetation in secondary successive ecosystems
Pipe in ground
- used to reconstruct vegetation history
- when they find that C14 decayed to N14, that is their estimates for when the plants died
- can take the DNA of this plant and animal species
Mammoth study
found that mamoths lived until 10,500 BP, several thousands years later than indicated from macrofossil surveys.
- mammoth and horse survival overlapped with humans
- contradicts the findings that extinction was due to extraterrestrial impact in late pleistocene
Allogenic succession
ex. fire, earthquake, volcano
- abiotic disturbances, flips to earlier state
Autogenic succession
biotic disturcances pushing back to earlier state
-ex. beaver den
why is old growth important?
more biodiversity
following secondary sucession, why is there a peak then decline in TOTAL biomass
- every leaf/branch/tree that falls and hasn’t decomposes
- eventually will decompose and steady state
How long does it take to reach late seral stages?
depends on area
- when environment is wet it will recover faster
how long did it take krakatau to recover
130 years
- 15 m of hot lava on island
how long would it take coastal bc rainforest to recover
- 1000 years for insect community
100 years for trees
how long would it take the arctic to reach late seral stages
~ 10,000 years
- because it is still changing
echological mechanisms for succession
- stochastic events
- facilitation
- Inhibition
- Tolerance
stochastic events
Unpredictable
- who gets there first can be well established
- major process in early seral stages
facilitation
- a species creates conditions favourable for succeeding species at expense of itself
- e.g. clover facilitates colonization of another species at the expense of itself (trees)
- leads to regular, sequential shit in species (assembly rules)
- major process in early seral stages
facilitation example
- predators cannot colonize successfully unless prey are already present
- pollinators cannot colonize successfully unless flowering plants are present
Inhibition
- species inhibits the colonization of subsequent species
e. g. allelopathy: chemical inhibition (coral reefs), competitive exclusion
Tolerance
members of a seral stage that co-exist due to the use of different resources
- combo of facilitation and inhibition
- ghost of competitions past
shoot to root ratio high vs. low seral state
high in early stages, low in late stages
