-combat with acoragia tentacles between differ clones of sea anemone
-limits asexual expansion over rocks
intraspecific indirect competition.
experiments with plant hoppers show that as become denser on leaf, survival, growth rate, body size, and reproductive output declines
-reveal nutrient concentrations of sap declined with increasing density
inter specific competition. define
different species compete.
inter specific competition. direct competition. example
small kelps grow thick enoguh to prevent light from penetrating which prevents establishment of sporlings of larger kelps
inter specific indirect competition.
Gause's experiments show Paramecium caudatum and P. aurelia deplete bacterial food source in mixed culture. eventually P. aurelia is drive to extinction because P. caudatum is more efficient in using depleted resources.
lives in close physical assocation with host to receive nourishment
-lowers fitness of host
Example of parasitism.
parasitic barnacle grows within decapods-host (crabs/lobsters) as branching system of tubules that extract nutrients and diverts most of host's energy to its own bulbous reproductive structure on outside of host.
-loss of nutrients from host and ormonal releases from parasite prevents crabs from devleoping functional gonads
one benefits and other unaffected
commensal and host live in close association, with former reciver nourishment/shelter
-does not reduce fitness of host
-many may be cryptic parasitisms or mutualisms
Example of commensalism.
pearl fish and sea cucumber: pearl fish would seek shelter in rectum of sea cucumber (host)
-both interactors increase fitness as result of exchange.
-evolved from parasitism or commensalism
example of mutualism.
Clownfish and Anemone.
Define facultative mutualism.
occurs between free-living partners.
-survival does not depend on interactions but when do, fitness changes. (better)
-no specialized structures assuring interaction may be present
-may exist with little co-evolution.
example of facultative mutualism.
wind pollination. requires no species interactions but costly, (requires high pollen ot ovule rations)
-animal pollination has much lower pollen to ovule ratios
Define obligative mutualism.
one or both partners MUST engage in interaction to survive or reproduce
-elaborate co-evolution often apparent
-specialized structures or behaviors exist and require energy to develop or maintain
example of obligative mutualism.
Ant and Acacia Plant: plant provides shelter, nector, proteins for the ants and ants protects palnt by remvoing herbivorous insects, also removes vines that over grow the acacia.
mutualistic association between plant and root fungus.
importance of mycorrhizae.
in woodlands and forests because hard for them to get essential nurtients. mycorrhizae provide nutrients to plants
experiment of mycorrhizae.
test whether mycorrhizae help plants acquire nutrients and whether fertility of soil determines if mycorrhizea are present.
treatments: mycorrhizal fungi with unfertilized soil/
mycorrhizal fungi with fertilized soil/
no mycorrhizal fungi
result: when nitrates available, mycorrhizea help plants acquire them=grow larger;
increased nutrient uptake by mycorrhizae increases host plant production.
Define hermatypic corals.
are hard corals and reef builders. stony corals.
define ecological succession.
more or less orderly series of species replacements following a severe disturbance
Define deterministic succession.
order of species is fixed and certain.
Define. stochastic succession.
Order is variable, thus occurrence of particular sequence probabilistic
Define Primary succession.
Process that occurs on newly exposed geological substrate.
Define Secondary succession.
occurs after distrubance removes a community without destroying the soil.
Define ecosystems ecology.
ecosystem ecology is sometimes considered as analysis of pathways in nature.
proposes unique physical conditions of earth environment are held in equilibrium by concerted action of all life.