Question

Question 7 (12 marks) 500 A 400 E 300 B 200 100 0 MAM.J JA S.O ND J F -100 C -200 month Figure 1. Carbon exchange rates from a northern hemisphere cold temperate deciduous forest ecosystem. Which of the lines A, B and C indicate Gross Primary Productivity; Net Primary Productivity; a. and Respiration (of heterotrophs consuming live or dead plant material)? b. Provide an estimate of the annual Net Ecosystem Production of this forest. Draw a similar graph for a Banksia woodland ecosystem in Perth that has not experienced fire for many vears. Include all three lines. as well as axis scale and labels. C. a C exchange (g m2 month1)

Answer 1

Ans.

(a) Since Net primary productivity = Gross primary productivity - Respiration, A shows the GPP, B shows NPP and C shows Respiration.

(b) Net Ecosystem Production = GPP - Rp + Rh + Rd

Rp = Respiration of plants

Rh = Respiration of herbivores

Rd = Respiration of decomposers

Here the availability of plants is less, and herbivores is more comparatively. Decomposers are also more and thus net ecosystem production is also more.

(c)

GPP NPP Respiration

labels and axis scales are same. since the share of trees is less, it will have less respiration and release of CO2. The NPP curve will lie little above what I have shown here. I am sorry, i could not make it correctly, please correct it.

I hope the answer is clear to you now, if you have any query, please leave a comment, i will try my best to fix it for you. goodluck