Multitrophic Interactions Flashcards
explain Trophic levels
- Fundamentally divided between producers and consumers
- Energy passes through each level
- Less energy is available at each level
- Consequently, the total biomass rapidly falls when climbing trophic levels
define trophic interactions
Anything done by members of one trophic level that affects members of another
define herbivory
- Second trophic level
- Take advantage of enormous level of resources offered by plants
- Dominated by insects
define predation
- Hunt and kill second trophic level and above
- Predators are often generalists, but some are specialists
define parasitism
- Similar to predation, but does not immediately kill host
- Extremely successful, accounting for much as half of all species
define parasitoids
- Either a subset of or adjacent to parasitism
- Key difference: host almost always die
- Include upwards of 100,000 insect species, primarily wasps and flies
explain how trophic levels are fluid
- Many organisms, including insects, change trophic levels or multiple
- This can create complex interactions bc they are context dependent
trophic levels are fluid - examples
- most parasitoids and all omnivores
- They may drop down or go up a trophic level when they become adults
- They may also feed on other insects when given the chance
how do organisms Finding prey
Predators and parasitoids can directly search for prey
finding prey - primary signals
- Visual
- Chemical
finding prey - problem
- a pairwise approach
- prey species are under selection to hide
finding prey: problem - how do prey hide
- Cryptic coloration
- Minimal chemical signature – lower their chemical signature, causes them to smell less
How do pairwise interactions expand?
they expand when something happens at one trophic level affects others
pairwise interactions expanding - examples
- Exotic plants outcompete natives, caterpillars starve, caterpillar predators decline
- Parasitoids reduce herbivore population, increasing plant growth or reproduction
- Plant defensive compounds may harm predators of herbivores on the plant
what are plant volatiles
- Organic compounds with a high vapor pressure and low water solubility
- they readily evaporate
- Parasitoids (and some predators) can detect this
What promotes production of plant volatiles?
- many things
- particulary damage
what are herbivore induced plant volatiles (HIPVs) are triggered by
- Damage-associated molecular patterns (DAMPs)
- Herbivore-associated molecular patters (HAMPs)
explain kin selection regarding plant volatiles
- Volatiles are detected by nearby plants that are relatives, and they prepare for defense
- Plants may have evolved volatiles to call for help
what are hyperparasitoids
- they target other parasitoids
- they wait until an insect is parasitized and then lay eggs within the parasitoid’s eggs
- Constitute higher trophic level
- they are typically specialists and have a narrow range of hosts
why do species want to be in a mutualism with ants
- Ants are good friends and dangerous enemies
- There are a lot of them
- Colonies persistent
- Ants are dominant predators in many systems
- Few predators want to mess with ants
why may an ant betray their mutualism partner
- Ants are protecting for a reward
- If another mutualist have a better reward, they will betray their current mutualist
How do multitrophic interactions shape communities
- Populations experience top-down and bottom-up pressure
- Many organisms require mutualists
- Dense networks are often required to maintain stability
explain Multitrophic interactions in the Anthropocene
- Phenology is altered
- Non-indigenous species are introduce to ecosystems
- Simplification of habitats and networks
multitrophic interactions in the Anthropocene - definition phenology
- cyclic timing of events
- Animals/insects have their own period to do things, climate change changes phenology
