D4.2 Stability and change

Question 1

stability

Answer 1

the ability to maintain or support systems and processes continuously over time

Question 2

what in natural ecosystems maintain stability

Answer 2

steady conditions with continuous supply of rainfall and sunlight, combined with warm temperatures, absence of disturbance and some other factors

Question 3

example of forest left undisturbed

Answer 3

switzerland urwaler left without management or anthropogenic use

Question 4

stability short defenition

Answer 4

absence of change

Question 5

community stability

Answer 5

is due to the absence of disturbance or community resitance to disturbance

Question 6

restistance

Answer 6

the ability of a community or ecosystem to remain unchanged despite disturbance

Question 7

resiliance

Answer 7

the ability of an ecosystem to rebound from change

Question 8

what does the structural and functional stability depend on

Answer 8

• steady supply of energy
• nutrient cycling without leakage
• absence of disruptions which would interfere with sustainability
• climatic variables within tolerance limits
• high genetic diversity so populations can survive selection pressure

Question 9

how do these disruption compromise the stability of ecosystems: erosion

Answer 9

leads to nutrient loss and reduces soil fertility a and weakens plant growth

Question 10

how do these disruption compromise the stability of ecosystems: harvesting and removal of materials

Answer 10

disrupts nutrient cycles and food webs-leading to imbalance

Question 11

how do these disruption compromise the stability of ecosystems: eutrophication

Answer 11

excess nutrients from fertilizers cause algal blooms- oxygen deplation, fish kills population imbalance, reduces biodiversity

Question 12

how do these disruption compromise the stability of ecosystems: poaching and selective removal

Answer 12

removal of keystone species, distrupts ecosystem structures

Question 13

tipping point

Answer 13

ecosystem stability can be compromised by so much disturbance that a critical point is reached from where a reversal might be difficult or impossible

Question 14

what do positive feedback loops do

Answer 14

have tendancy to amplify the effects and drive a system to a point where a new form of stabiliry or equilibrium is reached

Question 15

deforestation of amazon rainforest as an example as a possible tipping point

Answer 15

amazon rainforests habe experiences increased frequencies of drought. the main reasons which contribute to this are the burning and deforestation to make space for grazing land and housing. mining further leads to loss of forest habitat

Question 16

why the water cycle is important for the sustainability of the amazon ecosystems

Answer 16

1) trees transpire water vapour
vapour rises into clouds returns as rain
trees support each other shared humidity
2) rainfall recycling, amazon acts as green ocean pumping moisture inland
3) interdependance of trees via underground network= less trees= less transporation= less rainfall= more tree loss
4) global impact- contributes to global climate regulation, dostruption can cause regional drying

Question 16

amazon rain forest where?

Answer 16

covers a very large part of south america, spanning over brazil, peru, ecuador and columvia. it contains half of the planets remaining tropical rainforests

Question 17

simple water cycle IB

Answer 17

heavy daily conventional rain
trees intercept rain
some rain reaches the ground
trees take up water
water evaporates

Question 18

why is the rainforest needed for the generation of water vapour

Answer 18

the cycle is fuled by rainfall, transpiration in plants, evaporation and air flows

Question 19

what is GFW and their mission

Answer 19

the global forest watch is used to monitor forest deforestation in real time using satelite data being analysed in seconds. seeing where and when this clearing is happened to prevent iegal forest loss etc.

Question 20

example of uses

Answer 20

-find ilegal deforestation
- businesses use to see if suppliers are clearing forests they are planning to attend
- all people can monitor the data, public gaining wealth of information

Question 21

primary forest

Answer 21

forest that has never been significantly disturbed or modified by human activity.

Question 22

richness

Answer 22

number of different species present in a particular area-variety of species
higher richness= healthier more stable ecosystem

Question 23

rarity

Answer 23

refers to how uncommon or scarce a species is in ter of its geographic distriution, population size, habitat specificity.
may be endangered

Question 24

how can stabilty and sustainability be monitered

Answer 24

using models such as mesocosms- small experimental areas that model ecosystems. can be controlled

Question 25

things that should be considered when setting up a mesocosm

Answer 25

- glass or plastic containers - transparent or opaque material - which organisms should be included to make up a sustainable community how can continuos ocugen be supplied

Question 26

keystone species

Answer 26

species in a ecosystem that are critical to the survival of other species in the system- without them the ecosystem would not survive

Question 27

example of keystone species

Answer 27

american beaver in north america. perform unique role in ecosystem

Question 28

how beavers contribute to the stability of ecosystems

Answer 28

beavers are ecosystem engeneers that build dams and lodges transforming streams into ponds and wet landd. these changes to the abiotic envioment create stability beaver dams store water and regulate stream flow, reducing flooding and drought. beaver also create slow down water, allowing sediment and organic matter to settle. this improves nutrient availability and filter pollutants remove treet,opens canopy,letting sunligjt reach ground, promote shrubs and aquatic plants- increases primary productivity

Question 29

how beaver affects the survival of other species within its community

Answer 29

- dead standing trees in bond serve as nesting sites for owls, woodpeckers' - ponds serve as habitat for frogs, insects - used as burrow for shelter for mammals - support species across multiple trophic levels - increase food web support

Question 30

what is meant by a beaver being a ecosystem engineer

Answer 30

beavers cmake abiotic and biotic modification- changing chemical ad physical conditions of the enviorments and these changes benefit other species

Question 31

effects of beaver on deadwood

Answer 31

when beavers cut down trees to build das and lodges, many tree stumps and trucks are left behind. these trees are ooded and become snags. this wood is deadwood is importants as nestsm and aids decomposition. also become nutrient cycing area

Question 32

how do beavers contribute to flood redction in areas he lives

Answer 32

Build dams that slow water flow and create ponds/wetlands. Reduce downstream flooding by holding back and gradually releasing water. Store excess rainwater, acting like natural sponges. Increase groundwater recharge through soil infiltration. Stabilize water levels during both wet and dry seasons. Vegetation growth in wetlands absorbs water and prevents erosion. Act as ecosystem engineers, regulating abiotic factors for long-term stability. Provide a key ecosystem service: natural flood control.

Question 33

what are amphipods

Answer 33

significant keystone species which contribute largley to the stability and biodiversity of aquatic ecosystems and communities- exist as essenrial role in ecosystem functon ( fish food, leaf litter degration) invertebrae

Question 34

where are amphipods found

Answer 34

found in both freshwater and marine ecosystems, specifically calm shallow vegetated areas

Question 35

why are amphipods a keystone species and why is it ecological significance

Answer 35

act as decomposers accelerating nutrient recycling ecosystem cleaners- prevent buildup of organic waste act as key prey species bioindicaters as they are sensetive to pollution

Question 36

sustainability

Answer 36

the reponsible maintenance of ecological systems so that there is no reduction of conditions for future generations, ensuring long-term viability of a system

Question 37

forest management in finland

Answer 37

finish forests provide food, shelter, employment, and income 70% finland is forrests provisions on use of forests are laid down to prevent forest damage. forest act provides framework for forest management- achieve sustainable harvesting, allowing replanting implementing legistations

Question 38

sustainability management in fisheries

Answer 38

many fish like cod are almost extinct due to overfishing international conservation programmed implemented population size, age, reproductive growth used to determaine fishing

Question 39

what is sustainable fishing

Answer 39

Sustainable fishing is the practice of harvesting fish in a way that keeps fish populations healthy, protects marine ecosystems, and allows fishing communities to continue their way of life long into the future. It means only taking what nature can replace.

Question 40

Why Are Longlining and Purse Seining Considered Unsustainable?

Answer 40

longlining- uses thousand of bated hooks, catches many fish at once,catched non target species purse seining uses huge net to circle and trap school fish- traps entire school including babys, catces other marine life

Question 41

examples of sustainable fishing practices

Answer 41

using cicle hooks fishing quotas marine protected areas catch release methods seasonal closures during breeding areas

Question 42

factors affecting the sustainability of agriculture

Answer 42

soil erosion fertilizers leaching carbon footprint monocultures

Question 43

soil erosion

Answer 43

caused by tillage, which involved growng harrowing and results in reduction of quality of soil

Question 44

leaching

Answer 44

soil exposure can lead to leaching of nutrients from the soil. when it rains, nutrients are washed away and not available anymore for plants

Question 44

carbon footprint

Answer 44

the use of heavy machines and glass houses use a lot of energy and release many greenhouse gases

Question 45

fertilizers

Answer 45

growing crop causes nutrient depletion over time which needs fertilizers to compensate. excess nitrogen and phosphates leads to leach in water systems and possibly eutrophication

Question 46

monocultures

Answer 46

repeated growth of some of the same crop results in pests and lack of diversity

Question 47

eutrophication

Answer 47

the excessive nutrient enrichment of water. nutrients such as phosphates and nitrates favour the growth of algae, whch multiply in great numbers and lead to algae bloom

Question 48

why is algae bloom a problem in ecosystems

Answer 48

light blockage, low levels of ocygen from decomposers consuming oxygen in water some algae releases tocins ligt blockage prevents photosynthesis breaks food chain as it cannot be eaten

Question 49

how does eutrophication occur detailed explanation

Answer 49

1) nutrient load up in water causes plants to flourish and grow 2) algae blooms preventing sunlight from reaching other plants, prevents photosynthesis 4) decomposition of plants, decomposers use more oxygen in water 5) death of ecosystem from low levels of oxygen

Question 50

how can eutrophication occur naturally

Answer 50

through gradual drying up of pools of water and disproportionally increasing the amount of nutrient rich sediment

Question 51

what does BOD measure

Answer 51

amount of dissolved oxygen requires to break down organic material in a given volume of water

Question 52

what does bod allow us to determaine indirectly

Answer 52

bod allows us to determine water quality and aerobic activity by bacteria.

Question 53

how is BOD determained

Answer 53

by taking a measured volume of water from a source and measuring the dissolved oxygen content on day 1 using an oxygen probe. the same is then places in the dark to prevent photosynhesis at 20 degrees for 5 days. after the level of oxygen is measured again. difference of initial and dinal oxygen calculation

Question 54

what is BOD levels dependant on

Answer 54

the body of water being tested. shallow slow moving waters such as bonds and wetlands will have large amounts of organic material in the water and high bod levels.

Question 54

bioaccumulation

Answer 54

is the increase in the concentration of a toxin in body tissues during an animals lifetime. usually happens with fat solube chemicas which cannot be excreted

Question 54

link of eutrophication and BOD

Answer 54

eutrophication increases BOD as when bod rises oxygen levels fall. eutrophication means more organix matter in water

Question 55

why does eutrophication reduces the length of an aqauatic food chain

Answer 55

loss of top consumers fromow oxygen fewer produces from blocking sunlight simplify food webs

Question 56

biomagnification

Answer 56

increase in the concentration ofa chemical at each sucessive trophic level in a food chain. predetors tend to accumulate higher chemicals of a toxin than their prey because larger quantities are consumed

Question 57

explain how pollutants such as mercury or lead can become biomagnifying in animals

Answer 57

mercury enter water from coal, mines etc it becomes methylmercury, a toxic form tiny organisms like plankton take methymerc small fish eat that accumulate murcury bigger fish like tuna eat small fish= more murcury top predetors eat fish= have a lot mercury mercury does not break down it builds up

Question 58

what is DDT

Answer 58

example of an insecticide used in agriculture that was banned as it accumulated in the fat tissue of animals

Question 59

the 2 main types of plastics

Answer 59

microplastics- tiny less that 5mm eg, beads fibres of clothing macroplastics are greater that 5mm eg, plastic bottles etc

Question 60

what are the effects of micropatics on ocean

Answer 60

entanglement ingestion: blockage of digestive tracks, starvation habitat disruption, floating plastic piles effect coastal ecosystems

Question 61

effect of microplatics in ocean

Answer 61

bio accumulation passed in food chain' toxicity when absorbing harmful chemicals reproductive and development issued like reduced fertility' disuption of feeding when clogged reduce biodivertity

Question 62

origin of microplatics

Answer 62

polyester clothes stormwater runoff erosion and sus paint degration trash and littering

Question 63

what is rewilding about

Answer 63

about returning land and oceans to a more natural state

Question 64

examples of rewildering projects

Answer 64

distributing seeds of plants reintroduction of apex predators and other keystone species re- establishing connectivity between fragmented parts of exosystem control of invasive alien species removal of livestock

Question 65

kineway reserve example

Answer 65

Located in New Zealand, this reserve is a rewilding success. Once farmland, it was left to regenerate into native forest, supporting native birds, insects, and plants. It shows how passive conservation can restore biodiversity and help fight ecosystem degradation.

Question 66

ecological is succession

Answer 66

an orderly process of change over tie in a community

Question 67

what are abiotic factors that cause sucession

Answer 67

Light availability (e.g., more light in early stages, more shade in later stages) Soil type and nutrients (e.g., bare rock → thin soil → richer soil) Temperature and climate Water availability Fire, flooding, or drought (start or reset succession) Wind and exposure Pollution or erosion pH of soil or water

Question 68

biotic factors that cause sucession

Answer 68

Competition (for space, light, water, nutrients) Predation and herbivory Symbiosis and mutualism (e.g., lichens in primary succession) Decomposition (adds organic matter to the soil) Seed dispersal and colonization by pioneer species Invasive species (can alter or delay succession)

Question 69

primary sucession

Answer 69

primary succession begins with acompetley barren enviorment with very early colonizers generating small amount of growth on which more and more communities develop.like bare rock. pioneer species arive and grow, more species join

Question 70

secondary succession

Answer 70

occurs where a disturbance has cleared away an exiting community but leaves the soil intact

Question 71

pioneer community

Answer 71

pioneer community is the first stage of an ecological succession that contains hardy species able to withstand dfficult conditions whith little nutrient availability. examples : mosses, fungi, lichen etc little interspecific relationships

Question 71

cyclical succesion

Answer 71

species replace each other over time repeatedlu without very large disturbances. dominating climax communities are regulary replace by others. examples- fires occur every 15 years in australia, causing grasstrees to regow. flower as a result of fire

Question 72

climax community

Answer 72

climax community is a community of organisms that is more or less stable, and in equilibrium such as climate. it is the end point of ecological succession. it includes large trees and dense forests. complex interspecific relationships

Question 72

example of cyclical succession

Answer 72

honecomb barnacles atatch to bare rock custose algae colonizes' black mussels settle on top smoothes barnacles and algae underneath mussles detatch, bare rock available again

Question 73

2 examples of plagioclimax

Answer 73

pastoral grazing: cattle sheep etc on pasture protected from predation, continuously feed on grass, other plants are always removed and will never grow into climax community wetland drainage: swamps and wetlands are specialized ecosystems with many plants and animals adapted to anaerobic conditions in soild. wetland accumulate peat. drainage is often performed to make these areas habitable for crops housing or extraction of peat.