Lab 8: An Investigation of Energy and Biomass Relationships in an aquatic ecosystem

Question 1

What is the problem with insolation?

Answer 1

It is measured in many different units and therefore we have problems being able to compare different systems.

Question 2

What is Insolation?

Answer 2

Is all the energy available to the primary producers (autotrophs in an ecosystem). No new energy being made.

Question 3

LCE Light capture efficiency=

Answer 3

GPP/Insolation X100

Question 4

Most systems capture less than what percent for LCE?

Answer 4

Less than 1%

Question 5

How much of the GPP is converted to NPP?

Answer 5

Primary Producers ahve first opportunity to use GPP. They use the sugars produced in photosynthesis in one of two ways:
1.) Some is converted to biological molecules used in production of new plant material
2.) It can be burned so this sugar is lost to the system as heat.
So basically any GPP that is not lost to respiration or heat is the amount that NPP gets.

Question 6

NPP:

Answer 6

The amount or proportion of GPP that is converted to new body tissues and is therefore available to the next trophic level.

Question 7

NPP (Net primary production)=

Answer 7

GPP-R

Question 8

NPE (Net production efficiency)=

Answer 8

NPP/GPP X100

Question 9

Consumption Efficiency (CE):

Answer 9

The amount or proportion of NPP of the preceding trophic level that is consumed by the next trophic level

Question 10

CE=

Answer 10

Conusmption/ NPP of the preceding trophic level X100

Question 11

Ecological Efficiency (EE)=

Answer 11

NPP or NSP / NPP or NSP of preceding trophic level

Question 12

Respiration Rate:

Answer 12

is a measure of the amount of GPP burned in cellular respiration

Question 13

RR=

Answer 13

R/GPP X100 or RR= 100-NPP

Question 14

Does water run out of lake Nakura?

Answer 14

NO, it is a closed basin. however in periods of low precipitation it has been dry in 1961.

Question 15

How does it salinity fluctuate?

Answer 15

Fluctuates with the water levels which is an effect of the balance between precipitation, runoff and evaporation.

Question 16

Lake stratifies on a daily basis….

Answer 16

the surface water is usually supersaturated with oxygen during mid day but water near the bottom sediments have little oxygen. Afternoon winds destratify the water restoring vertical homogenity of temperature and oxygen.

Question 17

What is the most prominent species?

Answer 17

Lesser Flamingos 58% of primary consumer biomass.

Question 18

What is the major primary producer?

Answer 18

The Blue-green alage (98% of the biomass of primary producers). forms almost continual water bloom.

Question 19

What are a couple of the second consumers?

Answer 19

Pelicans (mostly pelican they eat almost all of the fish production 90%) and greater flamingos( mostly eats copepods)

Question 20

Total incident radiation was

Answer 20

9260 KJ m-3 d-1

Question 21

Lindemanns rule:

Answer 21

The amount of energy transferred from net production at one trophic level into net production at the succeeding trophic level is always less than 10%.

Question 22

Ecological Efficiency:

Answer 22

describes the efficiency with which energy is transferred from one trophic level to the next.

Question 23

Mean Residence Time:

Answer 23

measure the average amount of time that objects remain in a system.

Question 24

Turnover Rate:

Answer 24

is the ratio between net production and the dry weight biomass for that trophic level.

Question 25

The lake is relatively high in nutrients derived from the local…

Answer 25

volcanic soils, agriculture and sewage.

Question 26

Does RR increase in trophic level?

Answer 26

yes

Question 27

Does NPE increase or decrease with trophic level?

Answer 27

Decreases! Because secondary consumers use energy for flying and maintaining heat.

Question 28

Normally CE increases with trophic level, why does it not in this case?

Answer 28

Because flamingos are filter feeders so don’t have to move a lot and are super efficient.

Question 29

Why can biomass pyramids look very different?

Answer 29

Because it depends what organisms are there! The char one looked very different.

Question 30

PAR:

Answer 30

The amount of light available for use in photosynthesis by plants of the community.