BIOL214Z Ecology - Mick Hanley [1] Flashcards

Question

invasion concepts models to show how the characterstics map on ecologically to the rapid spread in new environments

Answer 1

any introduced species (out of its native range) have been removed from normal predators such as pathogens or herbivore control. Therefore they are free from natural controls a decrease in regulations by natural enemies resulting in increased distribution potential and abundance in new habitats. carpenter & cappuccino. We tested the enemy release hypothesis for invasiveness using field surveys of herbivory on 39 exotic and 30 native plant species growing in natural areas near Ottawa, Canada, and found that exotics suffered less herbivory than natives. showed that non-native suffered less herbivory then plants ranked as less invasive. Invasion potential and being attacked by native herbivores show, show a pos correalation

Answer 2

comes from plant defence theory. plant defence theory suggets that poorly defended by fast growing genotypes should be most favoured if herbiory is reduced. evolution should choose for ability to grow quickly and reproduction not plant defence. Eica: less represented as it takes a long time. Some hints at a shift in adaptive traits joshi & tielborger (2012) compared plant size and susceptibility to herbivory in native european and introduced north american loosestrife populations plants grown in common conditions in germany- the north american variety grew larger as expected because putting resources into plant growth instead of herbivore defence. Thus the na showed more herbivory then european. Rapid resource aquisitation and reduced herbiovore defence

Answer 3

fish from the great lakes had fewer parasites then the native fish (ERH) evidence that enemy release hypothesis is occuring. EICA not yet demonstrated in animals

Answer 4

numerous examples in the literature where the introduction of a species to a new region causes the decline or loss of native species. -competiton, exploitation

Answer 5

the process by which the negative impacts induced on native ecosystems by one or more non-indigenous species are exaggerated by interactions with another species.

Answer 6

ants (technomyrmex albipes) were introduced to to indian island ocnea. the ant deters attacks on the native plant ( leucaena) its main herbivore (decrease in plant growth and seed produciton when the ants are excluded). native plant (taccada)- the ants aid the herbivore by protecting sap-suckling bugs from predation (therefore removal of ants aids plant growth) conclusions: ants protect invasives plants but main herbivores but exacerbates the effects of herbivory on the native. thus helping the non native plant species (leucaena) further invade into the enviornment

Answer 7

Pine martens (looks like a stout) find it harder to predate smaller Red squirrels (they can get to smaller branches) Reduced Grey numbers free’s Reds from resource competition and reduces infection by squirrelpox virus

Answer 8

global habitat loss: greatest loss of biodiversity 80% of land service has been transformed by human activity 60% of earths ecosystems are seen as degraded. (mea 2005) shows this- grasslands and woodlands highly affected loss of habitat on ecosystem services- reduces provisioning and cultural services. Loss of mangrove habitat (1/3 pre industrial) of mangroves since 1980- *vital for coastal protection root systems good for wave attenuation (storm energy taken out by tangeled web of moangrove roots) sediments trapping abilty, nutrient cycling, carbon sequestration, habitat for fish species (nursery) estimated $1.billion of ecosystem services provison is provided by mangrove habitat (therefore this money would be needed to restore this)

Answer 9

25% loss- tropical forest value: $3.8 trillion for raw materials, c-sequest, genetic resources. Old estimates. 30% loss- sea grass beds: nutrient cycling, wave attenuation, fish nursery= $3.8 trillion (costanza et al) 25%- sand dunes: sediment supply, wave attenuation, recreation for human well being. Lose sediment supply in one area, loss in another.

Answer 10

the decline in bumble bee diversity and abundance linked to habitat loss together. As well as changes in the management of honey bee colonies and diseases. why does a lack of pollinators matter? Essential for crop production: crop production (bean, fruit family, wild flower) all used to set seed, thus produce crop ES= $153 bil (2005) allied services also at risk Economic valuation of the vulnerability of world agriculture confronted with pollinator decline: 1) the contribution of insect pollination to the world agricultural output economic value, 2) the vulnerability of world agriculture in the face of pollinator decline. We used a bioeconomic approach, which integrated the production dependence ratio on pollinators, for the 100 crops used directly for human food worldwide as listed by FAO.

Answer 11

Neonicotinoid insecticides have been implicated in these declines because they occur at trace levels in the nectar and pollen of crop plants. We exposed colonies of the bumble bee Bombus terrestris in the laboratory to field-realistic levels of the neonicotinoid imidacloprid, then allowed them to develop naturally under field conditions. Treated colonies had a significantly reduced growth rate and suffered an 85% reduction in production of new queens compared with control colonies. Given the scale of use of neonicotinoids, we suggest that they may be having a considerable negative impact on wild bumble bee populations across the developed world.

Answer 12

Hanley & Wilkins (2015) compared bumblebee abundance either side of arable hedgerows in devon and cornwall- margins facing the roadside tended to have a higher level of bees present. Then the margins that faced the crop. Road facing tend to have more flowers and more flowering species. Red campion (mean abundance) is more common on the road facing side then crop facing (an important pollinator) herbicides also favour for fast growing chemical imputs fertilliser use tends to favour fast growing species like grasses and nettles etc the hedgerow creates a barrier between the flowers and the pesticides

Answer 13

https://besjournals.onlinelibrary.wiley.com/doi/10.1111/j.1365-2664.2006.01249.x paper: Comparing the efficacy of agri-environment schemes to enhance bumble bee abundance and diversity on arable field margins

Answer 14

certain bumblebees are fussy eaters and rely on specific species to feed on.b.humils-92% members of the facaeae (pea family) large preference for fabaceae

Answer 15

study looked at micromoth species from meta data spanning from 1970's to now to register abundance. 260 declined, 160 increased. most species associated with low nitrogen and open environments decreased.

Answer 16

agri-environment schemes (AES) provide finacial incentives to farmers 3 levels (entry, organic, higher) farmers can enter ecological stringent cerfitication schemes to aid pollinator provision (www.conservationgrade.org) AES options include: EF4/OEFA: small strips of pollen and nectar flower rich areas EB1-2/OEB1-2: reduced cutting enhanced hedgerow management. To facility less disturbance to nesting and hybernating bumble bees

Answer 17

HK6- maintain existing spaces (paying farmers for good practice) HK7-restoration former species rich to new semi-natural HK8- creation of semi natural grassland from scratch

Answer 18

legume- based seeds EF4-blocks of flowering rich areas within fields- produce many more flowers and brought more pollinators EF3- late season mix provided earlier and later vital forage resources. Have to think about their life history prospects. As they need forage to start out (stresses the impotance of seasonal flowering in the flower rich strips) schemes are benefical to bumble bees but not necessarily other pollinators.

Answer 19

schemes have benefical to bumblebees but not any other species many authors have reviewed ESS some say there was no inpacts on bee/wasps and others say consevation grade schemes are better then AES

Answer 20

oilseed rape comprises 11% in UK of land space. Field beans take 4% both crops present flower rich resources for 2 to 3 weeks (an important mass floral resource for pollinating insects) bumblebee abundace in germany? oil seed rape and bumblebee abundance westphal et al (2003) found that bumble density was greater in areas containing oilseed rape herrmann et al (2007) suggested increased nest size linked to Mass Flower Crop cultivation

Answer 21

recorded more bumble bees in hedgerows closer to bean flowering period but only for that amount of time.

Answer 22

likey that bees are attarcted the BECs for forage and hibernation/nesting sites

Answer 23

exploitation of biodiversity isnt new. Large herbivores (mega fauna were globally common until 11k bp) now only in saharan africa.

Answer 24

many debates if ovr exploitation has attributed to mega fauna death. Where anthropogentic or climate change causes. example: 9 moa species in new zealand have gone extinct, due to human hunting and habitat change. 600 years ago. (flightless bird species)

Answer 25

*over exploitation by humans has a signifcant role in their demise. *consuming large amounts of vegetation *soil disturbance * redistributing nutrients *affecting behaviours of other animals

Answer 26

african savannah- combination of open grassland and acacia thickets. this is maintained by a combination of fire and grazing. Elephants are a keystone species

Answer 27

first dispersed by elephants in their dung, most samplings are killed by fire and herbivory. After a while the acacia will be consumed to the point where theres nothing left to burn and they will slowly start to be able to reform. ungulates forced to migrate and look else where once stablished in the absence of their predators, the growth of saplings can be rapid (reaching a metre tall within a month) been fertilised by the dung spinesence develops which aids fire retardancy... thus aiding plant development under the thickets elephants then return: migrating elephants will mow down the entire area of even aged thickets. Pushing over to eat the green leaves at the top of the canopy. smaller ungulate species then return to repress acacia development further

Answer 28

thickets vs grassland as a consequence of light vs shade demanding grasses elephant activity also effect ungulate behaviour. many of them activly avoid thickets and prefer open grassland areas. As predators use thickers as cover to smbush prey.

Answer 29

wolves in scotland: high deer densities with a cobination of sheep grazing theirs a big shift in tree composition

Answer 30

wolves were hunted to extinction in 1920's *return in mid 1990's. Immediate effect on deer populations and their foraging behaviour. *browsing areas declined and tree height increased. *increase in aspen height along rivers as predators have a better chance here, tken to higher up the valley on hills

Answer 31

lots of tree species increased other herbivore species such as bison also increased as they dont experience as much competition

Answer 32

only can be reeastbalished with keystone species. A lot of these are extinct so they cannot be returned. Therefore using proxy species. Therefore taking biota out of their now habitat and putting them in another.

Answer 33

reintroduction of tool elf in LA- biggest effect was on annual species (both on native and non-native) grass species saw a positive change had both diserable and undiserable effect. Disturbunce hypothesis

Answer 34

the most diverse floras are assoicated with low nutreint soils Western south africa: -high alpha diversity- up to 130 species per 1000m2 -high beta diversity (turnover)- changing soils, frequent fire, long evoultionary history. Due to leaching the soils are dedicent in: nitrogen, phosphorus, molybdenum, copper

Answer 35

park grass experiment in 1856 had 89 different plots varying in nutrient treatments. plant species richness, biomass and pH are related; community composition responds to climatic perturbation and nutrient additions; soil is acidified and corrected by liming. the study also showed a putative case of the evolution of reproductive isolation by reinforcement expierment showed vegetation responds to increased fertility. higher nitrogen levels= more plant diversity but less species richness. cow slips, oat grass.

Answer 36

low fertility- many species can co-exist as because superior predators are unable to dominate. Therefore co-existence. under higher nutrient conditions these stronger competitors dominate and eliminate inferior species.

Answer 37

plant size increases so space decreases plant height increases so light decreases

Answer 38

All organisms face the issue of obtaining nitrogen. 80% of air we breathe is N2 its in an unreactive form therefore unobtainable. obtainable organic compounds: reactive nitrogen species: urea, ammonia etc.

Answer 39

1. Biological n-fixation: bacteria living free from or associated with plants (ES costana) 2. mineralisation: occurs via weathering, decomposition 3. atmospheric depositon

Answer 40

the amount of nitrogen deposition has doubled since industrilaisation. From the atmposhere to the biosphere. where? some is from industrial sources, whilst the rest agriculture: nitrogen fertilizers, cultivation of nitrogen fixing crops. 20o million t yr= only part of this is defitrified.

Answer 41

the haber-process allows us to convert atmospheric N to ammonia. therefore can create synthethic fertilisers therefore excess run off into ecosystems/ aquatic systems post industrial- excess of man-made nitrogen sources

Answer 42

cultural eutrophication- man made nutrient imputs into aquatic systems denote a change between plants/ animals and often algae broad-scale eutrophication norfolk broads- fertilliser runoff and sewage. peak of phosphorous constrations in the river in the 1970's. signficant increases in algae plants and a decrease in plants. phase 1- low nutrient= macrophytes dominate. phase2- increased nutrients, still macrophytes with epiphytes phase3- high nutrients shows high epiphytes and phytoplankton but macrophytes fazed out.

Answer 43

reduced macrophytes abundance removed refugia for the zooplankton that fish eat fish populations increase which control the phytoplankton. this leads to a fish population crash after a while phytoplankton thrives

Answer 44

*fertilliser/ sewage runoffs causing increased nutirent loading in esturays around the coast lines. *not just an aquatic phenomina

Answer 45

ascot et al 2017 vadose zone (interphase between soil surface and groundwater) greater in north america, europe, asia.

Answer 46

1. gas toxicity 2. toxic effect of nh2 3.acidification 4.impact on plant growth/competiton 5.disruption of interactions (herbivory, mycorrhizae)

Answer 47

plant quality many change: could be benefical for herbivore, increase in aa content, reduction of carbon secondary defence in the plant. could be increase in nitrogen based secondary defences chemical

Answer 48

any effects that the change of host plant quality have on the abudnace of herbivores could in turn have a selective impact on other plant communties. (selective impacts) strauss in 1987 showed a change from beetles to aphids. increased herbivory results in faster nutrient cycling.

Answer 49

does species diversity change? we know this from the field experiment.

Answer 50

different responses across different biomes alpine: reduced shrub/bryophyte cover boreal forest: reduced shrub, increased graminoid. mediterrranean forest: dramatic change in lichens understory invasion by exotics. tropical savannah: increase in sedges, loss of grasses and exotic grass invasion.

Answer 51

species diversity and species richness can vary depending on the ecosystem involved. long history of n-deposition shifts many have already happened/ before ecologists started taking note. but areas that havent seen much n-depo before such as alphine vegetation shows these predicted losses

Answer 52

Clear responses were seen across the sites with the greatest sensitivity shown in cover and species richness of bryophytes and lichens. Productivity was also increased at sites where N was the limiting nutrient, while flowering also showed high sensitivity, with increases and declines seen in dominant shrub and forb species, respectively. impacts can ‘build up’ within an ecosystem such that even relatively low N deposition rates can result in ecological responses if continued for long enough.

Answer 53

vascular plant species limited changes at realistic n deposition bryophytes and lichens negative sensitivity. To experimental lichen addition. due to a combination of firect toxicological effects but also due to an increase in vascular plant species growth.

Answer 54

tendancy to focus on vascual rplants but these hold many important processes. important role: * water retentio (mosses, lock away flood water) *locking away elivated nitrogen depositons (excess carbons, in peat that they form) *therefore carbon sequestration

BIOL214Z Ecology - Mick Hanley [1] Flashcards

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