mutualisms Flashcards
what is a mutualism
the association of two species which is beneficial to both = ALLOWED INSECTS TO DIVERSIFY
what is a symbiotic mutualism
a close association which benefits both individuals
- can be obligate = required for survival and repro e.g. termites and microbes
- can be faculative = beneficial but not essential e.g. stick insects and ants
Give some examples of mutualisms
in return servives resources or protection e.g.
pollinaton/insect-plant interactions
insect-microorganism interactions such as intestinal bacteria
insect arthropod interactions e.g. aphids and ants
what are the different categories of mutalisms
45% British spp mutualistic
1) Exploitative/ nutritional = new resource is gained
2) physical/ immune =protective
3) dispersal/transmission = includes pollination
outline an exploitative or nutritional mutualism
when an individual gains the ability to use a new resource by acquisition of mutualist
- may improve nutritional value of food or make new resources available
e.g. microbial interactions help to digest cellulose providing energy/nutrition
outline what a protective mutualism is
when one species protects another e.g.
thorns or stems (domatia) for ants to test in whilst the ants protect the plant from herbivors
or
ants protect aphids from predators and use honey due
outline a dispersal/transmission mutualism
- dispersal of fruits or seeds, tranmission of pollen
- pollination is a significant ecosystem service
- fig wasps pollinate figs whilst feeding on the seeds
- spores of mosses and fungi transported whilst acting as food
what is a commensalism mutualism
a mutualism when the host is unaffected
- phoretic = uses host for transportation
e.g. bark beetle galleries provide resources for inverterbrate and microbial commensals
what are the ecosystem services provided by mutualisms
1) pollination
2) seed dispersal
3) fungal dispersal
what is biotic pollination and how has this impacted flower evolution
the transfer of pollen from anthers to stigma by another organism
= plants have evloved flowers to encourage pollinators by providing attraction and reward e.g. colours and fragrance
how is pollination an ecosystem function
= essential for individual plant spp and wider community of organisms associated with plant and pollinator
outline pollinator evolution
1) fossil evidence suggests coleoptera + diptera acted as early pollinators
2) associations between coleoptera and angiosperms during early cretaceous beloved to have led to parallel radiation of angiosperms and insects into late cretaceous
3) evolution of nectaries in late cretaceous indicates beginning of mutualisms between hymenoptera and angiosperms
how does pollination act as an ecosystem service
by pollinating crops world wid
= global cultivation of insect pollinated crops led to 300% increase in deman for pollination services
= eco value $215 billion
what are some impacts of pollinator decline
- cost UK up to £440 million a year
- affects to crop yeild
-insect pollinated plants declining faster than wind pollinated
how do insect spp provide the ecosystem service of seed dispersal
= removal of seed from plant to another location - seeds knocked to ground in feeding or carried from plant
= influences structure of plant communities
= some plants derived relationshsips with animals to help spread seeds
