interspecies interaction Flashcards
competition among plants
most plants need the same resources:
water nutrients light co2 …
competition. among animals
wide range of resources -> more types of competition
feeding: predator-prey
compertition for resources
using other organisms as habitat
types of interactions
neutral mutualism commensalism competition amensalism predation parasitims parasatoidism
(0,0) neutral for both
neutral
(+,+) both mutually benefit
mutualism
(+,0) one species benefits and other neutral
commensalism
(-,-) both species compete
competition
(+,-) one species feed on the other and killing it
predation
(+,-) one species feed on the other reducing fitness but not killing it. A needs B
Parasitism
(+,-) one species feed on the other reducing fitness but not killing it. A doesnt need B
Parasatoidism
predator prey relation
if predator population increases -> pressure on prey increases
the more the easier to catch prey
the more prey the more reproduction of preditor
morphology vs physiology
structure vs function
species interaction & natural selection
seeds and birds
plants produces bigger and smaller seeds bird prefers smaller seeds bird reduces small seed plant fitness small seed die out plant gets larger seeds bird is AGENT OF SELECTION bird with small bill die out -> only large seeds available -> feedback loop...
two species that evolved and are dependent on eachother
FACHBEGRIFF
coevolution
niches? 3 niches
ecological niche:
range of physical and chemical and biological conditions under which a sopecies can thrive
fundamental niche:
envir. conditions under which a species can survive theoretically
can be determined in an experiment
realized niche:
the actual niche that a species inhabits due to interaction with other species
differs along environ. gradient
hutchinson
mutlidimensional hypervolume:
many many axes of conditions an organism needs to survive
every condition a range:
result a multidim. hypervolume
importance of knowledge of niches
if ecosystem is restored
mutualism and commensalism effects niches
they can widen up a fundamental niche
example: bacteria, that enable roots a wider range of soil
interspecific competition: 2 types
consumption competition:
different species compete for same resource
preemption competition:
different species want the same space
examples of bacteria competition
separately grown -> both thrive
if together one thrives and other dies
the one that succeeded could better cope with density stress
separately grown -> both consumed silica
together one had no chance as the other had a higher affinity to silica
competitive exclusion principle
complete competitors cannot coexit (same ecological requirements & conditions remain constant)
environmental change on niche
examples
can totally change everything -> other species takes niche
when rain increases in a place, humidity tolerant species starts to thrive
biodiversity
collection of species in a space and time
thistles in competition
why biodiv?
when grown alone (monoculture) and in mixture
different result in biomass allocation
some dominant in low, medium or high nutrient conditions
therefore biodiversity is important to adapt to many scenarios
plants living together
they all take what they can and get:
light water ect
mixed root lengths…
effect of coevolution
leading to phenotypic divergence
leading species to use an enviroment independant of competition
-> niche divergence and hence to bio-diversification
predator prey cycle
result in population cycle for both predator and prey
experimental problems for prey cycle
need to be in an open environment, so immigration is possible-> landscape ecology
prey cycle w/ primary producer
rabbits eats tree -> many rabbits, less trees (stress on tree) -> more lynx -> less rabits -> more trees ->…
energyflux from tree to lynx
grass needs herbivores?
eats grass and makes it less competitive
eat small trees
if leaves lost plants may increase photosyn
autotroph protection(2)
they can not run away!
structural defense: hairy leaves, thorns, spines
secondary compounds: chemicals: nicotine, morphine, tannins (60% of dry weight!), lignins
