Nutrient Cycling

Front 1

What is Liebig's Law of the Minimum?

Back 1

The resource that is the most scarce is the one that most influences population numbers

Front 2

What is the process of downloading?

Back 2

The act of carrying nutrients from terrestrial ecosystems through freshwater systems into marine ecosystems

Front 3

What is the process of uploading?

Back 3

The act of carrying nutrients from marine ecosystems into freshwater ecosystems, usually through bird defecation or fish carcasses.

Front 4

Rivers discharge what 5 things into the marine ecosystem?

Back 4

1. Sediment

2. Trace elements

3. Dissolved organic matter

4. Nitrogen

5. Phosphates

Front 5

Salmon carcasses provide what two nutrients for ulva in estuaries?

Back 5

Phosphorus and Nitrogen

Front 6

What are riparian zones?

Back 6

Riparian zones are forest habitats that are adjacent to a stream that is influenced by stream parameters like hydrology and nutrients

Front 7

In Dr. Reimchen's 1993 study on salmon carcasses transferred into riparian zones at Bag Harbour, which gender did bears take more of overall?

Back 7

Males

Front 8

In Dr. Reimchen's 1993 study on salmon carcasses transferred into riparian zones at Bag Harbour, what percentage of salmon in the stream were found to be transferred over the course of the study?

Back 8

65%

Front 9

Why is it unnecessary to set up a culling of the Black Bear population in Bag Harbour in order to preserve salmon species?

Back 9

Because most of the predation bears have on salmon is on those that are post-reproductive; Reimchen's study showed that the average male eaten had spawned 5-8 times before capture, while 70% of the captured females had spawned out. This study has proven that bear predation has a low negative effect on the reproduction of salmon.

Front 10

What is the main limiting resource for vegetation in coastal forests?

Back 10

Nitrogen

Front 11

Nitrogen accounts for how much of the total mass of salmon tissues?

Back 11

3%

Front 12

How much nitrogen do salmon carcass remnants account for in riparian zones (in kg/hectares)?

Back 12

120 kg/hectare

Front 13

How much of the Earth's atmosphere is nitrogen?

Back 13

78%

Front 14

What two types of nitrogen isotopes exist in the atmosphere and how much do they each account for the total nitrogen? Which one is the heavy isotope and which one is the light isotope?

Back 14

Nitrogen-14 : Light isotope accounting for 99.3% of total nitrogen

Nitrogen-15: Heavy isotope accounting of 0.7% of total nitrogen (or 7 ppt)

Front 15

When do relative amounts of 15N vary?

Back 15

In biological systems

Front 16

Compared to atmospheric nitrogen, what two terrestrial species have lower nitrogen isotope ratios?

Back 16

Deer and trees/shrubs

Front 17

What is d15N equal to?

Back 17

0

Front 18

Compared to atmospheric nitrogen, what two terrestrial species have higher nitrogen isotope ratios?

Back 18

Wolves and bears

Front 19

Compared to atmospheric nitrogen, what four terrestrial species have higher nitrogen isotope ratios?

Back 19

Salmon, small fish/sandlance, zooplankton, and phytoplankton/algae

Front 20

Overall, do terrestrial or marine species exhibit a higher d15N value than atmospheric N?

Back 20

Marine species

Front 21

Are nutrient levels higher above or below waterfalls? Why?

Back 21

Below waterfalls, as many salmon and other species get caught below the waterfalls as they cannot swim back up them

Front 22

How much of the nitrogen in riparian plants come from salmon nutrients?

Back 22

Up to 80%

Front 23

How did Dr. Reimchen determine whether or not the presence of salmon increase the growth rate of plants?

Back 23

They took cores of ancient trees, measured the yearly growth rings, and graphed it against the number of salmon returning each year.

Front 24

Does the presence of salmon increase the growth rate of plants?

Back 24

It is unknown how much of the growth is directly due to salmon rather than to other factors such as rainfall and temperature.

Front 25

How much of the Winter Wren's insect diet is salmon-derived?

Back 25

30-95%

Front 26

Is Wren density higher below or above the falls? By how much?

Back 26

About 50% more dense below the falls

Front 27

How much of the fall diet of wolves is salmon?

Back 27

About 20%

Front 28

Are bear populations more dense on watersheds with or without salmon, and by how much?

Back 28

They are 40X greater on watersheds with salmon

Front 29

How much of the autumn protein consumption of bears is derived from salmon?

Back 29

95%

Front 30

How much of the yearly protein consumption of bears is derived from salmon?

Back 30

30-80%

Front 31

What is the major species that transfer salmon into forests around the North Pacific?

Back 31

Bears

Front 32

How much salmon can a bear transfer into the forest during a 6 week spawning period?

Back 32

Up to 700 salmon

Front 33

In carcasses/km/year, how many carcasses are transferred onto spawning reaches of rivers each year?

Back 33

Average of 1000 carcasses per km per year

Front 34

How many kg of carcass remnants are currently left in BC forests by bear

Back 34

2.4 million kg

Front 35

Between salmon and bears, which is the dominant and which is the keystone?

Back 35

Salmon are dominant

Bears are keystones