Challenges To Biodiversity

Question 1

What is an invasive species?

Answer 1

Species introduced into areas outside of native range
Can cause/have caused harm in their new area
May outcompete native species for resources, habitat = alters community structure and could lead to extinctions

Question 2

E.g. invasive plant

Answer 2

Kudzu

Prickly pear

Question 3

Describe invasive species kudzu

Answer 3

• Japanese arrowroot
• e.g. of species introduced into new ecosystem with high resources and few preauthorise
• introduced to USA from Asia in late 1800s as ornamental plant
• planted widely in south USA in early 1900s to reduce soil erosion
• plants grow very rapidly and enshrouds almost everything including other plants and even houses in vines

Question 4

Describe invasive species prickly pear

Answer 4

• were imported into Australia in 19th century: natural agricultural fence, established cochineal dye industry
• rendered 40,000 km2 of farm land unproductive
• moth from South America; larvae eat prickly pear so was introduced in 1925 and almost wiped out pop = successful biological pest control

Question 5

What are the effects of introduced species

Answer 5

Sometimes there is a time lag after introduction of a species before spread and exert impact
Introduced species do constitute major ongoing global change
Recognised as second greatest cause of species endangerment and extinction (after habitat change)

Question 6

What are the types of impact of invasive species

Answer 6

• habitat modification
• predation
• herbivore
• parasites and pathogens
• competition
• hybridisation

Question 7

Describe habitat modification

Answer 7

LOOK AT SLIDES FOR E.G.s

• grazing, browsing and rooting by introduced mammals
• aquatic introduced plants overgrow and shade out native plants
• introduced plants modify natural fire regimes
• introduced plants change habitat by using vast amounts of water
• plants fix nitrogen; when such species invade nitrogen-poor areas, they fertilise the soil

Question 8

Describe predation

Answer 8

LOOK AT SLIDES FOR E.G.s

• some invasions reduce or eliminate one/a few native species
• some invasions lead to community-level changes

Question 9

Describe herbivory

Answer 9

LOOK AT SLIDES FOR E.G.s

- often devastates native plant species and sometimes entire communities

Question 10

Describe parasites and pathogens

Answer 10

LOOK AT SLIDES FOR E.G.s

- introduced parasites and diseases can affect individual native species and occasionally entire communities

Question 11

Describe competition

Answer 11

• introduced species can compete with native species to the point of extinction
• e.g American grey squirrel caused drastic decline in pop of native red squirrel in the UK(similar may happen in Europe as grey squirrel spreads north form Italy)
• e.g. house gecko, caused decline several native lizard populations on Pacific islands by outcompeting natives for insect prey

Question 12

Describe hybridisation

Answer 12

-subtle but devastating impact

E.g.

• both New Zealand grey duck and Hawaiian duck hybridise with introduced North American mallard
• in Europe North American ruddy ducks hybridise with the dwindling native white headed duck, now restricted to Spain
• females of declining European mink hybridise with male introduced North American mink. Embryos are inevitably aborted but females removed for a year from the breeding population.

Question 13

What are the characteristics of invasive species

Answer 13

• fast growth.
• rapid reproduction
• high dispersal ability
• phenotypic plasticity (the ability to alter growth form to suit current conditions)
• tolerance of a wide range of environmental
• ability to live off of a wide range of food types
• association with humans
• prior successful invasion history

Question 14

Describe Japanese knotweed (fallopia japonica)

Answer 14

• listed by world conservation union as one of the worlds worst invasive species
• invasive root system and strong growth = damages even concrete foundations, pavements and roads
• reduces the capacity of channels in flood defences
• coloniser of temperate riparian ecosystems, roadsides and waste places
  - forms thick dense colonies that completely crowd out any other herbaceous species
  - success partially attributed to tolerance of wide range of soil types, PH and salinity, can survive temps of -35C, can extend 7m horizontally and 3m deep.
• plant resilient to cutting, resprouts from the roots
• is an offence to plant or cause it to grow in the wildm or spread it intentionally or unintentionally
• householders and landlords who dont control gardens can be fined or persecuted
• requires disposal at licensed landfill sites
• species is expensive to remove: costs 70 million to eradicate knotweed from 10acres of the London 2012 Olympic Games velodrome and aquatic centre
• national eradication programme estimated 1.56 billion
  Controlled release trials began in South Wales in 2016

Question 15

How much of the population lived in the city by the turn of the 20th century

Answer 15

15%

Question 16

What year witnessed the turning point when more than 50% of the world population were living in cities for the first time in human history.and who claims this?

Answer 16

2007

United Nations

Question 17

What is urbanisation

Answer 17

• population shift from rural to urban areas

- process by which towns and cities are formed

Question 18

How much of the developed and developing world will be urbanised by 2050?

Answer 18

Developed = 64%
Developing = 86%
(3 billion urbanites)

Question 19

In 2050, which continents will exceed 70% urban populations and which populations will exceed 90%

Answer 19

Asia and Africa = 70%

New Zealand and North America = 90%

Question 20

What are the environmental effects of urbanisation

Answer 20

• urban heat islands: formed when industrial and urban areas produce and retain heat
• in rural areas solar energy consumed by evaporation of water from vegetation and soil
• in cities, where less vegetation and exposed soil, sun’s energy absorbed by buildings and asphalt; leading to higher surface temperatures
• cities often 1 to 3C warmer than surrounding landscapes

Question 21

What causes ecological degradation

Answer 21

Extinction
Land use change
Ecosystem processes
Ecosystem services

Question 22

What is a built habitat

Answer 22

Buildings and sealed surfaces such as roads

Question 23

What is managed vegetation

Answer 23

Residential, commercial and other regularly maintained green spaces

Question 24

Ruderal vegetation

Answer 24

Empty lots, abandoned farmland and other green space that is cleared but not managed

Question 25

What is natural remnant vegetation

Answer 25

Remaining islands of original vegetation (usually subject to substantial non-native plant invasion)

Question 26

What is eutrophication

Answer 26

When rain occurs in large cities, it filters down pollutants such as CO2 onto the ground below.
Chemicals washed directly into rivers, streams and oceans, causing a decline in water quality and damaging marine ecosystems

Question 27

How many pollinating species are in decline

Answer 27

60%

Question 28

How many colonies of honey bees have been lost since 1985

Answer 28

54%

Question 29

What are urban avoiders

Answer 29

Very sensitive to human habitat disturbances

E.g. large mammals (bison), old forest birds, late successional plants

Question 30

What are urban adapters

Answer 30

Frequently found in sub-urban matrix areas

E.g. cultivated plants and weedy species, ‘edge species’ animals, and omnivore birds

Question 31

What are urban explorers

Answer 31

Synanthropes - even dependant on Human Resources

E.g. grasses and annuals, birds and mammals that inhabit and exploit human dwellings

Question 32

Describe light pollution

Answer 32

Presence of anthropogenic light in the night environment
- a major side effect of urbanisation: is blamed for compromising health, disrupting ecosystems and spilling aesthetic environments

Question 33

The effects of light pollution

Answer 33

• alters natural patterns of light and dark
• circadian rhythms can be affected
• many species specialise in activities in particular lighting conditions
• nocturnal processes of repair and recovery interrupted
• decisions to forage at night related to lighting evils
• light at night tend to favour predators
• interference with spatial orientation

Question 34

How to combat light pollution

Answer 34

• unnecessary lights extinguished or not installed
• spectrum chosen to minimise impacts (not UV or blue)
• as bright as necessary for purpose
• directed only where needed
• only illuminated as long as necessary

Question 35

The effects of urbanisation on human health

Answer 35

• on average rural health better than urban
• poor urban areas e.g. slums differ disproportionately from disease, injury and premature death
• urbanisation associated with improvements in public hygiene, sanitation and access to health care. Results in changes and occupational dietary and exercise patterns:
  
  • in children, urbanisation is associated with higher risk of overweight
  • body mass index and cholesterol levels increase sharply with national income and the degree of urbanisation
• chronic diseases more prevalent in urban environments