Community Ecology Flashcards

5094347762	Community	All species that exist in a certain area + interact - directly and indirectly	0
5094351934	How to species interact indirectly	Via an intermediate species	1
5094353814	Fitness	Ability to survive + produce fertile, viable offspring	2
5094356971	Interaction affects:	1) Distribution + abundance 2) Natural selection + coevolution 3) Dynamic + conditional	3
5106526408	Coevolution	2 species reciprocally influence each other's adaptations e.g. prey gets faster, so predator gets faster	4
5094367744	Commensalism	One species benefitted, one unaffected; conditional	5
5094373711	Problem of neutral effects	Difficult to quantify	6
5094375768	Competition	Lowers fitness for both species using the same resources	7
5094379662	When do interspecific interactions occur?	When niches overlap	8
5094386163	Niche	Range of resources species can use or range of conditions in can tolerate	9
5094393579	Symmetric Competition	Both species in overlap area persist, but at reduced population sizes	10
5094403000	Asymmetric Competition	One species suffers greater fitness decline; dependent on extent of niche overlap	11
5094415101	Competition Exclusion	2 species cannot coexist if they have identical niches - asymmetric competition	12
5094435470	Fundamental niche	Total theoretical range of niche	13
5094437072	Realised niche	Portion of fundamental niche species actually occupies - barriers, predators, competition etc. could be in way	14
5106543492	Niche Modeling	Using geo-referenced data from history collections + databases - get latitude + longitude points and their bioclim data	15
5106551841	What do you use Niche Modeling for?	Use software to predict distribution of fundamental niche; predict spread of introduced species; suggest new places to start recording abundance	16
5106564507	How to do experiments with competition	Remove one of competitors - observe response of other	17
5106570891	Niche Differentiation	Evolutionary change in resource use caused by competition over generations	18
5106582112	Character Displacement	Evolutionary change in species' traits enabling it exploit different resources - allows for niche differentiation when sympatric + asymmetric speciation	19
5106591702	Resource Partitioning	Occupying slightly different parts of habitat or using same resource slightly differently e.g. Warbler birds on a tree	20
5106598966	Sympatric	Speciation alongside other species	21
5106600856	Allopatric	Speciation in separate areas	22
5106611249	Consumption	Increases consumer's fitness, decreases prey's fitness	23
5106612968	Herbivory	Herbivores consume plant tissues	24
5106617869	Meta-Analysis	Study of studies- analysis of large data sets	25
5106627563	Top-down control of herbivores	Herbivore populations limited by predation + disease	26
5106629185	Bottom-up limitation	Plant tissues offer poor nutrition + well defended - have less than 10% nitrogen found in animal tissues of equal weight	27
5106642898	Why can't herbivores just eat more food to solve the nutrient problem?	Risk of predation too dangerous	28
5106645432	Parasitism	Host suffers, parasite gains	29
5106648090	Brood Parasitism	Birds lay eggs in nests of other species	30
5106651429	Controlling hosts/manipulation	Must transmit self between hosts; Zombie ants + fungus, flatworms controlling snails so the climb higher and look like caterpillars so eaten by birds	31
5106656431	Benefit of Parasites	Stop certain species dominating areas if populations get too large	32
5106661825	Social parasites	Using other species to raise young	33
5106692353	Why are parasites not all fatal?	Often much smaller than host	34
5106698890	Predation	Predator kills + consumes all/most of another individual	35
5106704691	Constitutive Defences	Permanent defenses against predation; present even in absence of predators, including cryptic colouration, escape behaviour, toxins	36
5106711248	Aposematic Colouration	Organisms that produce toxins are colourful	37
5106714101	Disruptive Colouration	When in a herd - cannot pick out individuals	38
5106723042	Mimicry	One species resembling another	39
5106726646	Batesian mimicry	Harmless or tasty species mimics a harmful one (Bates a companion of Wallace on Brazil trip)	40
5106735229	Mullerian mimicry	2 toxic species look similar - increases likelihood that predators learn to avoid them	41
5106739324	Aggressive mimicry	Predators mimic harmless species - innocent looking fly trap	42
5106798965	Inducible defences	Physical/chemical/behavioural traits induced in prey when predator present	43
5106803485	Example	Mussels have thicker shells when crabs present	44
5106809489	Benefits of inducible defenses over constitutive defences	Energetically efficient but slow to produce	45
5106820205	Phenotypic Plasticity	Genotype can produce different phenotypes depending on environment	46
5106829283	How do plants show inducible defences	Produce proteins e.g. radishes producing glucosinolates and trichome hairs when exposed to herbivores	47
5106835985	Indirect Inducible Defence by plants	Attract other predators to attack herbivores	48
5106847132	Prey's intrinsic growth rate (rmax) compared to predators	Larger - physically smaller animals, produce more offspring, mature earlier	49
5106849730	What is the Rmax value	Max. population growth rate achievable under ideal conditions	50
5106864256	Proof that predators still efficient in reducing prey populations	Population cycles, predator removal, biological control	51
5106870128	Predators advances	Speed, nocturnal vision, venom, surprise, strength, herd cooperation Owls - binocular vision, fringed feathers for silent flying	52
5106874899	Arms race	Due to predator + prey interactions and coevolution; traits increasing efficiency become more abundant - humans and plasmodium	53
5106909247	Biocontrol	Using predators or parasites to control pests - helps maximize production whilst minimizing use of insecticides/other harmful compounds	54
5106919395	Problem of biocontrol	Could be introducing invasive species	55
5106922313	Mutualism	Fitness benefits for both species involved	56
5106928417	Rewards from mutualism	Transporting gametes; getting food; housing; protection	57
5106931375	3 types of mutualism	1) Resource-resource based 2) Resource-service based 3) Service-service based	58
5106940031	Alternative name	Reciprocal parasitism (Judith) - not a form of species simply being nice to one another	59
5106944345	Deceitful mutualism	Deceit pollinators - attractive but provide no pollen, or nectar robbing - takes nectar without pollinating: cheaters; natural selection favours these	60
5106948879	Dynamic or static?	Dynamic - could switch from positive affects to one organism suffering in particular conditions - switches from parasitism, mutualism, to competiton	61
5106956010	Is sharing always equal?	No - can be asymmetrical e.g. plant roots and mycorrhizal fungi	62
5106971288	Increasing other species fitness instead of your own?	Natural selection does increase fitness of other species; but must increase own fitness too	63
5106974467	Ammensalism	Neutral effect on one species, negative on the other	64
5106982350	What does community structure depend on	1) Total # of species 2) Relative abundance of each species 3) Sum interactions among all species 4) Physical attributes of community - its abiotic factors and biotic factors	65
5107005781	Clements' Views on Community Predictability	1) Communities stable, orderly + predictable 2) Coevolution important - species unlikely to exist if other is not present too 3) Will reach the stable Climax Community - determined by environment	66
5107024909	Gleason's Views	1) Communities neither stable nor predictable 2) Matter of chance if community develops in same area after a disturbance 3) Believes less in importance of biotic factors and species interactions	67
5107038183	Experimental test on ponds and 2 possible hypotheses	1) If community predictable: each pond should develop in the same way 2) If community unpredictable: each pond should develop differently	68
5107044478	Reality	Both hypotheses partially correct; both biotic interactions + climate and chance + history important in determining species presence - range is independent	69
5114057829	Keystone species	One that has a large impact on community structure - greater impact of distribution + abundance of surrounding species than its abundance + total biomass would suggest - typically consumers/predators; maintains biodiversity/species richness	70
5114063129	How could the structural species be removed?	Harvesting, disease, competition with an invasive species, climate change	71
5114068112	Food Web	Network of exchanges of energy + nutrients among producers, consumers + decomposer - focuses on feeding interactions	72
5114072093	Use food webs to look at	Effects of keystone species	73
5114073410	Food chain	Single path within a food web	74
5114074939	Trophic level	Position of organism within a food chain	75
5157027509	Producer	Produces own biomass from inorganic compounds	76
5157030987	Consumer	Cannot produce own biomass from inorganic compounds, so consumers other organisms	77
5157039531	Decomposer	Fungi/bacteria that produce biomass by breaking down dead organisms	78
5114081618	Disturbance	Strong, short lived disruption to community - changes distribution of organisms + resources	79
5114087996	Examples of disturbances	Fires, windstorms, floods, tree falls, disease epidemics	80
5114092225	What resources could be changed?	Light levels, nutrients, unoccupied space	81
5114102635	Disturbance Regime	Predictable frequency and severity in particular areas - characteristic disturbance	82
5114112228	Why need a regime?	To maintain communities in good condition, must ensure normal regime or community composition changes dramatically	83
5114115694	Post-disturbance	Organisms replace those lost	84
5114118294	Primary Succession	Disturbance removes soil + organisms - after floods, volcanic eruptions, landslides	85
5114124280	How does soil reform?	Weathered rock; dead organisms and faeces add to the substrate organic matter; thick enough and roots can take hold	86
5114130149	Secondary Succession	Disturbance removes some organisms from area but leaves soil in tact - after fires + logging	87
5114141965	Pioneer species characteristics	Short-lived; small size; high dispersal range; small seeds; rapid growth; high reproductive rate; mature young; extreme condition tolerance	88
5114147966	Climax species	Long lived; large size; large seeds; good competitors	89
5114153613	What determines area's successional pathway	Traits of species involved; species interactions; historical + environmental conditions	90
5114160836	How are pioneers "weedy"	Adapted to disturbed soils; tolerant serves abiotic conditions e.g. light levels, poor nutrient availability, desiccation; devote most energy to reproducing not competing	91
5114167410	Facilitation	Early arriving species make conditions more favourable e.g. providing space, nutrients	92
5114170132	Tolerance	Existing species that don't affect subsequent species establishing	93
5114172771	Inhibition	Makes establishment of subsequent species harder e.g. trees blocking sunlight	94