Lecture 7 - Atmospheric N deposition

Question 1

Oxidised N exists as … in wet condtiions and … in dry conditions

Answer 1

NO3-

N2O

Question 2

Reduced N exists as .. in wet conditions and … in dry

Answer 2

NH4+

NH3

Question 3

Antrhopogenic emissions:
Power stations release …
Motor vehicles release …
Cows and other livestock release ..

Answer 3

SO2
NO2 - Nitrous oxide
NH3

Question 4

..Gt N is brought into the UK by outside of the UK

Answer 4

90 N

Question 5

..Gt N is released by UK into non-UK

Answer 5

321

Question 6

..Gt N is released annually by UK

Answer 6

723

Question 7

.. Gt annual N falls back on UK per year

Answer 7

402

Question 8

N is deposited faster to .. surfaces

Answer 8

rougher

Question 9

eutrophication allows the .. of .. species

Answer 9

expansion, nitrophilous

-can result in competitive exclusion

Question 10

soil acidification can cause base .. depletion

Answer 10

cation

• increasing toxic metal availability, causing species richness declines
• generally weaken plants

Question 11

secondary stresses are things like … and .. attack

Answer 11

herbivory

pathogen attack

Question 12

Dutch chalk grasslands provide an example of … as species … declined in 1980s concurrently with the competitive grass … ..

Answer 12

eutrophication, richness

Brachypodium pinnatum

Question 13

Increasing N deposition leads to .. species richness

Answer 13

reduced

• E.g. Brachypodium competitive exclusion
• Wardlow, Peaks gives evidence

Question 14

Grasslands accumulate up to ..% of the pollutant N deposition, maintaining provision of clean .. ..

Answer 14

75%
ground water
-Acidic grassland releases much more N than calcareous

Question 15

There are .. world biodiversity hotspots
Covering only ..% of Earth’s terrestrial area yet as endemics contain ..% of worlds vascular plant species (150,000+)

And also ..% of all terrestrial vertebrate species (12,000)

Answer 15

36
2.4%
50%
43%

Question 16

Distance from source is more important for .. than ..

Answer 16

NHy, NOx

-As NHy (reduced) is deposited closer to the source

Question 17

Greater .. can increase wet … via ..-.. effect

Answer 17

rainfall, deposition

seeder-feeder

Question 18

Orograhpic clouds are … clouds

Answer 18

feeder

Question 19

Stevens [2004] study suggested current UK N deposition (.. kg N) reduces species richness by ..-.. species

Peaks is at ..kg N and it nearly .. richness

Answer 19

17, 4-5

30, halves

Question 20

Thymus polytrichus is a .. grassland species while potentilla erecta is an .. grasslands pecies

Answer 20

calcareous, acidic

Question 21

global N deposition esitmated to be .-fold greater in 2050 than 1990

Answer 21

2

- N depo 3rd greatest threat to global biodiversity