chalk streams

Question 1

what is a chalk stream?

Answer 1

habitat and ecology or perennial chalk stream headwaters and future challenges.

Question 2

what gradient do chalk streams have and why?

Answer 2

low gradient, due to them forming from ocean beds, they’re very erodable.

Question 3

what percentage of the annual discharge may derive from groundwaters?

Answer 3

90%

Question 4

what is the temperature like in chalk streams?

Answer 4

relatively constant at around 11 degrees if a spring.

Question 5

what is the hydrology and flow like in a chalk stream?

Answer 5

relatively persistent hydrology and flow with dampened discharge fluctuations.

Question 6

what is the ratio between hydrology and flow?

Answer 6

3:1

Question 7

why are floods rare in chalk streams?

Answer 7

due to the large storage capacity.

Question 8

what is the substratum dominated by and why?

Answer 8

gravel, due to the geology, pebbles and gravel are sensitive to siltation, because of the low gradient and placid flow.

Question 9

what temperature are chalk rivers?

Answer 9

around 5-17 degrees.

Question 10

what are natural influences in chalk rivers?

Answer 10

feedback between organisms and the physical environment.

Question 11

how does a protected area influence chalk streams?

Answer 11

the flow is altered due to organisms.

Question 12

what are human influences on chalk streams?

Answer 12

structures such as mills, damns, ponds, drains, diches, and food defences.

Question 13

what river and bank managements are put into place to protect chalk rivers?

Answer 13

weed cutting, bank protection, rehabilitation, bank poaching, runoff from agriculture, and water abstraction.

Question 14

how does weed cutting protect the chalk rivers?

Answer 14

it makes it harder to fish due to the barrier and hydraulic resistance. if there is a lot of weeds, it will slow the water down and cause localised flooding.

Question 15

why is bank protection important?

Answer 15

ensure they’re maintained, no eroding towards houses.

Question 16

what is bank poaching?

Answer 16

when animals go into the water to drink or cool down and it causes the banks to erode away.

Question 17

how many of England’s rivers are altered?

Answer 17

95% of all rivers in England are altered.

Question 18

if we change one element of the chalk system, what effect does this have?

Answer 18

bottom-up- limited top. top-down- influences the whole structure. food webs and trophic interactions may get altered.

Question 19

a question to think about: is there a predominance of generalist or specialist feeders?

Answer 19

?

Question 20

a question: can we diagnose the causes of past changes and can we predict the impact of contemporary change?

Answer 20

?

Question 21

a question: can we use science to underpin decisions for the future?

Answer 21

?

Question 22

what will happen if a tree was put above the river?

Answer 22

there will be fewer algae, therefore this will affect the primary consumers.

Question 23

which level will be completely affected if algae decrease?

Answer 23

the primary consumers, but only if that is their main food source or only food source.

Question 24

how do you know if a chalk stream is meeting expectations?

Answer 24

if you know what to expect to do with eh conditions and the number of species.

Question 25

what species influence chalk rivers?

Answer 25

bird species

Question 26

what is important for chalk rivers and why?

Answer 26

specific hydraulic conditions and local channels. this is due to the local conditions.

Question 27

what is the Biota within each headwater stream influenced by?

Answer 27

local conditions, habitats, environmental conditions and ecology.

Question 28

what percentage of the world’s chalk stream resources are found in England?

Answer 28

85%

Question 29

what are the conservation goals for chalk rivers?

Answer 29

protection, enhancement of rare or threatened species.

Question 30

what are the ecosystem’s service goals for chalk rivers?

Answer 30

recreation, amenity, water resources.

Question 31

what are human use goals for chalk streams?

Answer 31

economics, socal and other benefits.

Question 32

how many of the rivers are protected?

Answer 32

out of 224 streams, only 12 are protected.

Question 33

what percentage of chalk rivers and classes as adequately protected and meeting conservation targets?

Answer 33

15%

Question 34

what species is making a come-nack with increased observed nationally?

Answer 34

otters!