BIOL214 Ecology - james Flashcards

Question

types of positive interaction (symbiosis)

Answer 1

interspecfic interactions (different species) mutualism- both species gain in fitness commensalism- one benefits but one is neutral

Answer 2

interspecifc and intraspecifc competition predatorism parasistm

Answer 3

a long term, close associated interaction, some cant live without each other. needs: net benefits must exceed cost each partner benefits

Answer 4

obligate example: Yucca moths and yucca plants have a reciprocal obligate relationship- the plants cannot make seeds without the yucca moth, and the moth larvae only reach maturity if they eat developing yucca seeds (Pellmyr 2003). falcultative: specific birds seed disepersal through flight.

Answer 5

long term close associsation where one benefits the isnt effected in anyway examples: -sharks and remora/sucker fish. aid movement through the ocean. -cattle egret

Answer 6

mycorzial fungi and plants (fungal network) plants produce carbohydrates (photosynthesis products) fungal hypae help plant take up nutrients from the soil (arbsucular and ectomycorzial)

Answer 7

ants and acacias how do ants protect the acasis trees, against inverts and mammals

Answer 8

manipulated the number of ants on the 4 trees and recorded tree damage (smoked trees) categories: control 1/3 ants removed 2/3 removed all ants removed once removed can look at how other animals interact with the trees (elephants, beetles etc) how does the acacia benefit? reduced herbivore damage increased chance of survival how to ants benefit? place to live nutrition from nectur from acacia

Answer 9

meta-analysis of lots of studies can compare statistically which benefits are most identified across studies. error bars over dotted line- not significant

Answer 10

endophytes in grasses- fungi deter herbivores We found that the effects of symbiont density on protection and cost are robust across ecological contexts. Density-function relationships did not vary with host type, symbiont localization or transmission mode, nor the method of density manipulation. Together, our results suggest symbiont density can be a key variable determining the costs and benefits of a protective interaction.

Answer 11

Direct effects on mutualisms on -keystone species which entire ecosystems then depend on examples: mangrove tree- rhizosphere, roots and other microorganisms- capture atmospheric nitrogen.

Answer 12

ant/acacia- enable trees to persist in areas that otherwise would not have trees (palmer and brody, 2013)

Answer 13

one species providing another a habitat for it to live in We show facilitation to be a ubiquitous driver of biodiversity by first noting that all species use resources and thus change the local biotic or abiotic conditions, altering the available multidimensional niches. This can cause a shift in local species composition, which can cause an increase in beta, and sometimes alpha, diversity. We show that these increases are ubiquitous across ecosystems. These positive effects on diversity occur via a broad host of disparate direct and indirect mechanisms. We identify and unify several of these facilitative mechanisms and discuss why it has been easy to underappreciate the importance of facilitation. We show that net positive effects have a long history of being considered ecologically or evolutionarily unstable, and we present recent evidence of its potential stability. Facilitation goes well beyond the common case of stress amelioration and it probably gains importance as community complexity increases. While biodiversity is, in part, created by species exploiting many niches, many niches are available to exploit only because species create them. an example of facillitation can increase community diversity: cushion plants facilitate each cushion plant species- 11 sites the number of plant species in paried design of with and wothout cushion plants. on average- more cushion plants more other plants. is the cushion suffering a loss? competition not bothered https://besjournals.onlinelibrary.wiley.com/doi/10.1111/j.1365-2745.2009.01579.x NMDS ordination indicated that cushions generate species assemblages structurally different from those found in open areas.

Answer 14

Bascompte et al. (2019). Mutualistic interactions reshuffle the effects of climate change on plants across the tree of life. Scientific advances. https://doi.org/10.1126/sciadv.aav2539 Extinctions induced by climate change may trigger coextinction cascades—groups of species disappearing as a consequence of the extinction of species they depend on—thus driving many more species to extinction than originally predicted

Answer 15

2 organisms using the same limited resource. Inter specific and intraspecific

Answer 16

direct competition: fighting or stealing food indirect competition: plants competitng for soil and light etc.

Answer 17

logistic growth curves: species introduced=exponential population growth. As the carrying capacity (k) is reached the population growth rate starts to slow. half of the K is the fastest rate of pop growth

Answer 18

low intraspecific competition

Answer 19

2 forms, negative density dependance. as populations increase then indivudals do less well. driven by increase of competition for resources but also predators and disease posititve density dependance (allee effect) individual fitness will increase the population size. (some groups benefit with more individuals around) example: blood flukes flatworm

Answer 20

lab: can check how strong the effect of compeition is by removing or adding resources field:uncontrolled background enviornment but can still add or takeaway observation: monitor the change of population in time. No manipulation. what to measure? population fitness (growth) competitive effect (suppress a neighnour) and response (ability to tolerate a neighbour)

Answer 21

badgers vs foxes (mesocarnivores) used randomised badger culls to see if removing badges effected foxes. results across 4 study areas: how consistnet are the result? 3/4 areas showed an increase i foxes. this suggests there is comp and when badgers are removed there are an increase of foxes.

Answer 22

meta-analysis of 35 pairwise plant species, showed competition is common in nature. intra specific competiton showed more of an impact

Answer 23

fundamental niche and realised riche.

Answer 24

competitive exclusion: local exclusion of a competing species niche differentation evolutionary change in symparty coexistence

Answer 25

grey squirrels replacing grey squirrel

Answer 26

predictions: -coexisitng competitors should show niche differentation -potential competitors with little or not niche change wont co-exist. example: the grants different finches that have adapted to reduce competition and get into new niches.

Answer 27

niche differences allow for species to co-exist. As similae species with similar niches will experience more competition

Answer 28

when 2 species have an indirect effect on each other by both being prey for the same predator. say a hawk who preys on mice and on squirrels. Say theres a rise in squirrels then the mice will be better off as they might eat more squirrels.

Answer 29

group of interacting organisms attributes such as number of species, types and relative abundance study of processes that shape identity and species abundance the number and abundance of species present in a community defined using: species richness (S) species eveness (E)

Answer 30

Diversity measure- species richness and eveness

Answer 31

mutualism competition and niche diversification

Answer 32

when you look at a community they arent at equillibirum. Constant flux. Disturbance is a temportary change in environment that causes a pronounced ecosystem change. examples- *mechanical- boulders rockshore *phyico/chemical- acid rain disturbances can be periodic or annual flooding or can be cercastic davis and mortiz (2013)

Answer 33

paper downloaded

Answer 34

extremes- Good predators dominate when theres low disturbance intensity. (competitors) At a contrast few species can tolerate high levels of disturbance. (stress tolerant pionners) But when a mix theres a stress tolerant species occur so a mix of the 2 creates a higher species richness

Answer 35

small boulders expected to be moved more often then bigger ones by wave action. Intermediate size boulders which are moved around occasionly but not that often. Measured the Force used to move a boulder. If a boulder is moved around constantly then dominated by green alga and barnacles. Red algae on intermediate and large. 2 dates in which they collected data N= number of boulders checked in each force class intermediate= has the optimised number of species.

Answer 36

founder controlled- competiton is low and disturbance high, community is dominated by things that come in (the founders). Example grass on chalk land. As grazers coming in and out frequently its disturbed. Dominance controlled community-high competiton and therefore disturbance becomes quite rare theres pioneer species but good competitors start to dominate. example in sand dunes

Answer 37

Ecological succession: change in community competiton and structure over time due to disturbance *Primary succession: on newly formed geological substrate (community completely lost at start- when glacials retreat the grass under that) *Secondary succession: After a forest fire, soil is intact but the distrubance has changed parts.

Answer 38

mount st helens video

Answer 39

volcanic eruption- 1) early pioneers, early sucessional species, high nutrient but no big trees, sparse vegetation that likes light (lupin) fixed nitrogen 2) transitional species: competitive start to establish for light etc- 36 years post. some trees and bushes but lots of meadow still. 3) late successional- back to post eruption. Big competitive trees.

Answer 40

changing conditions elevate biodiversity. Same forest with gaps in it will equate to smaller and less competitve species filling those niches

Answer 41

*small scale- diseased or old trees *felling - allows pioner species *large scale- storm *extreme- volcano opening up the canopy

Answer 42

tree diversity in ghana disturbance index % of pioneer tree species present. fewer pionners fewer disturbance index. plots showed reduced species where theres extremes and the most in the middle. *applies to tropical forests, but disturbance contributes little to tree diversity

Answer 43

fire adapted communities: processes occuring early stochastic processes and late in sucession (niche based). looked at fynbos, post fire succession on plant species and herbivorous arthropods. number of interacting species were sampled at different quadrat level. how this community built up over time plant increase over time, but at overtime theres a large jump up when habitat becomes more liveable. Looked at specalised interactions, more specalist species changes in a positive manner. thus generalist species at the start and more specalist further on. (niche differentation)

Answer 44

an interaction where there one member benefits and the other exploited

Answer 45

i=d ii=b iii=c iiii=a

Answer 46

the impact of rhese interactions on communities depends partly on the level of specalism of the interaction. for example snails are fairly generalsit with what they eat. But the large white capitillar are specalised on cabbage family.

Answer 47

lab field obvs what to measure? population or individual fitness compare fitness before or after manipulation resistance or tolerance mechanisms

Answer 48

allan and crawley (2011) looks at insect and molluscs exclusion and the interactions between them. Using insectersides etc to create exclusion in fenced and unfenced areas and looked for 14 years exclusion in factorial design. data showed: describe the effect of insects and molluscs on plant species richness.

Answer 49

species richness is greater when insects are present in grassland but reduces biomass, independent of molluscs. Molluscs tend to have a slight negative effect on species richness and increase biomass overall. the effect of molluscs are dependent when insects are present or absent, but biomass bigger overall.

Answer 50

pocock et al: ecological network sampled from one organic farm. Detail the different interactions that are occuring. (example inverts on an organic farm, herbivory, parasitism, leaf miners, rodents feeding on seeds) lots of interactions taking place, between plants and inverts. adding negative interactions- the interactions become more complex.

Answer 51

enemy release 'experiments' hoffmann (1998) prickly pear cactus- invasive in australia and south africa but not in USA. why? cactus moth and scale insect control growth in the USA introducing enemies in australia worked but variable in south africa. studies show- naive enemies might ignore introduced organisms because they dont know what it is. they dont have the correct signals to identify importance of coevolved predators

Answer 52

lynx-rabbit (predator prey) specalised herbivores: cinnabar moth+ragwort cyclical dynamic where more of one equals less of another the next year

Answer 53

lodgepole pine vs mountain pile beetle. *Endemic phase at the start: a few beetles around that are attacking the old trees. *Epidemic phase- go for healthier trees. *peak infestation *post-endemic phase- resistant trees remain and others die- run out of host material. then other trees would thrive during this time

Answer 54

in the aleutian archipelago: kelp forms large sturctures on the sea floor and the main food source for sea erchins. sea otter decline due to killer whales, lose of sea lions. thus this had an impact on the sea urchin grazing intensity. rasher et al 2020 Bioerosion rate and sea urchin mass correlated. and rising sea surface temp determine kelp feeding.

Answer 55

gps radio collar data from female elf and wolves in yellowstone estimated time spent by elf and wolves in different locations through time. predicted kill occurence openess kill density wolf density wolf density tends to be linked to open areas where kill density is higher on the elk.

Answer 56

100's species per hectare exploitative interactions could be the cause invertebrate herbivores/ pathogens thought to be important in tropical forests. species-specific enemies make the area around a parent tree inhositable for offspirng (conspecifics) negative species dependance

Answer 57

natural: biotic and abiotic artifical (uncertain how organisms will respond): pollution, urban environments

Answer 58

habitat destruction, fragmentation, degradation, invasive species introduction, climate change

Answer 59

artifical light (light pollution) across plymouth sound/ tamar estuary Using a combination of mapping, and radiative transfer modelling utilising in situ measurements of optical seawater properties, we quantified artificial light exposure at the sea surface, beneath the sea surface 76% of the three-dimensional seafloor area was exposed green wavelengths was high

Answer 60

-trampling of slow growing alpine plants -species being brought up to mountain areas -spread of disturbance-adapted mountain plants (alpine rock cress). common plant pf disturbed rocky areas. It thrives quite well in the disturbance.

Answer 61

when disturbance starts occur outside of their evolutionary history. novel types/intensity: reduced fitness as they are not adapted to the amount things are happening natural not anthropogenic examples: volcanos earthquakes

Answer 62

forest fires

Answer 63

noise pollution in the ocean takeaway people- wildlife returns (seen during covid) Young coral being effected by noise pollution at the moment many ecosystems are being disturbed too much.

Answer 64

looked at 19 different responses (behaviour etc) of species to extreme events (drought, fire, storms) what were the effects of these extreme responses on a number of organism groups some animals arent as well represented. mostly neg responses. short term responses Extreme weather and climate events have profound implications for species and ecosystem management. We discuss current conceptual challenges associated with incorporating extreme events into conservation planning efforts, which include how to quantify species sensitivity and adaptive capacity to extreme events, how to account for interactions between extreme events and other stressors, and how to maximize adaptive capacity to more frequent and intense extreme events.

Answer 65

impact of too much disturbance, too much fishing causes decline in heterogeneity and things cant repopulate quickly enough due to overfishing.

Answer 66

loss of keystone herbivores (megafauna) native richness is low in many regions of megafauna consequence of late pleistocene extinctions (human driven) megafauna have been introduced across the world but alot arent native but for agricultural reasons etc

Answer 67

looking for that intermediate spot

Answer 68

-degraded habitat being more susceptible to invasive species -extreme climate and invasive species mountain pine beetle: large scale tree death humans- salvage logging or new samplings. But they're all the same age and once reaching maturity are attacked again by beetles and cycle contiues

Answer 69

example: algal blooms- clear water to green algal blooms- nutrient inflow from agriculture hard to switch back to the og slate dry degraded grassland turning to desert

Answer 70

graham et al (2021) used socials to to devise cohesive stat for studying disturbance. distinguish between: disturbance drivers: what causes the change distrubance impacts: what happens after

Answer 71

beavers in plymouth rewilding (increase biodiversity and ecosystem resilliance, uses wildlife- active habitat management (human involvement) is to protect a particular species that is important to us can rewilding replace habitat management chalk grasslands (calcareous) would this environment exist in a rewilding concept?

BIOL214 Ecology - james Flashcards

(111 cards)