Lecture 16- Lotic Systems

Question 1

What does the location of headwaters affect?

Answer 1

-Productivity
-Phenology
-Diversity

Question 2

Headwaters south of arctic bring _______

Answer 2

Additional nutrients

Question 3

Why does the change in water level affect diversity in river systems?

Answer 3

-Difficult for establishment of fish
-Glacier fed more dynamic and nutrient poor which is challenging for primary producers and inverts

Question 4

Why does ice scouring affect riparian habitats in river systems?

Answer 4

-Can scape out new channels
-Increase erosion and sediments in the water
-Remove vegetation from shorelines
-Ice damming can cause flooding
-Anchor ice moves substrate needed for inverts and small fish

Question 5

What are the two main characteristics of river systems?

Answer 5

-Changes in water level affect diversity
-Ice scouring affects riparian habitats

Question 6

What are some characteristics of stream systems?

Answer 6

-Seasonal flow
-May have no flow in winter
-Fed primarily by snowmelt
-1st order streams connect lakes and other systems

Question 7

What are the three types of Arctic streams?

Answer 7

1. Mountain streams
2. Spring streams
3. Tundra streams

Question 8

Describe some characteristic of mountain streams

Answer 8

-Flow originates from surface runoff and springs
-Runoff from snow and ice melt
-Peaks in spring
-Flows ~5months of the year
-Freezes in winter
-Cold water temperatures
-Carry silt and nutrients

Question 9

Where does the flow originate in mountain, spring and tundra streams?

Answer 9

Mountain streams = from surface runoff and springs
Spring streams = from springs
Tundra streams = runoff

Question 10

What do mountain streams carry?

Answer 10

Carry silt and nutrients

Question 11

Do mountain streams freeze?

Answer 11

Yes, unfrozen for about 5 months

Question 12

Describe some characteristics of spring streams

Answer 12

-Flow originates from springs
-Warmer, underground flow
-Small streams
-Relatively stable throughout the year, some do not freeze
-Stream edges often with abundant plants
-Low amounts of silt

Question 13

Can spring streams stay unfrozen all year round?

Answer 13

Yes, some do not freeze because of warmer underground flow

Question 14

Describe some characteristics of tundra streams

Answer 14

-Originates as runoff
-Small, meandering (single channel or braided)
-No flow and ice covered in winter
-More stable water flow than mountain streams
-Associated with wetlands
-Water is slow, shallow
-Warms up in the sun
-High daily variation in temperature
-Low pH, travels through acidic tundra

Question 15

Are tundra streams frozen in the winter?

Answer 15

Yes

Question 16

______ has more stable water flow than ______

Answer 16

-Tundra streams
-Mountain streams

Question 17

True or False. The temperature of tundra streams stays constant?

Answer 17

False (the temperature varies because it can be warmed up easily)

Question 18

Describe the arctic river food web

Answer 18

Question 19

Where do you find benthic invertebrates?

Answer 19

-High diversity in spring streams
-Very low in mountain streams
-Spring streams flow all year round

Question 20

Why would benthic organisms like spring streams?

Answer 20

-Relatively constant amount of water
-Warmer water, higher nutrients

Question 21

Benthic invertebrates have _____ of taxonomic groups and ______ to extreme conditions

Answer 21

-Small number
-Highly tolerant

Question 22

What are some fishes present in Arctic freshwater systems?

Answer 22

-Arctic char
-Arctic grayling
-Round whitefish
-Slimy sculpin
-Ninespine stickleback

Question 23

What two fish are ecologically and culturally important?

Answer 23

-Arctic char
-Arctic grayling

Question 24

______ is a keystone species of arctic streams

Answer 24

Arctic Grayling

Question 25

What are some examples of Arctic Graylings

Answer 25

Trout, salmon

Question 26

Arctic graylings stay within ____

Answer 26

Freshwater for their whole lifecycles but typically migrate from larger freshwater bodies into smaller streams to spawn (typically tundra streams)

Question 27

Where would you find Arctic Grayling?

Answer 27

Found in all streams

Question 28

Where do Arctic Graylings spawn?

Answer 28

Tundra streams

Question 29

Arctic Grayling spend their winters in ______

Answer 29

Lakes, which brings the influx on nutrients

Question 30

Why does climate change do to groundwater and Arctic Grayling?

Answer 30

-Groundwater flow increasing with climate change (permafrost thaw)
-Shorter ice cover period
-Increased nutrient load in water
-Young fish grow faster, higher survivorship

Question 31

What are some effects of climate change on arctic grayling?

Answer 31

-Reduced oxygen due to plant decomposition (reduced adult winter survival)
-Earlier spring thaw and spring discharge disrupts migration (leaving lake habitats earlier
-Less rain in late summer (trapped in dried up streams, cant return to lakes)

Question 32

What are some effects of climate change on lotic systems?

Answer 32

-Shifts in runoff regimes (more precipitation as rain)
-Thinner ice cover, more available habitat
-Shifts in ice breakup timing and severity (reduction in spring flooding which provides nutrients and sediments)
-General increase in productivity in streams

Question 33

Decrease some effects of permafrost thaw

Answer 33

-Thaw slumps increase sediment loading (can choke out aquatic organisms, can cut off or alter stream flow)
-Alterations in nutrient cycling

Question 34

Describe the diagram of effects warming temperatures have on permafrost

Answer 34

Question 35

Permafrost thaw = _______

Answer 35

Decreased surface runoff

Question 36

What does permafrost thaw do?

Answer 36

-Streams can now flow into taliks
-Provides subsurface flow and storage

Question 37

What does permafrost thaw promote?

Answer 37

-Promotes the growth of taller shrubs along streams
-Changes microbial community
-Alters vegetation community
-Shades stream
-Shrubification