IB ESS Unit 2: Ecosystems & Ecology (id: 5f2887164)

本题目来源于试卷: IB ESS Unit 2: Ecosystems & Ecology，类别为 IB环境系统与社会

[单选题]
Figure: Energy flow in a tow5,aw7(e pxx(6 ji:cs fqmz :errestrial ect1qf5 i.p/xt bosystem in kJ $m^{-2}yr^{-1}$



Calculate the percentage flow of net primary productivity (NPP) from producers to tertiary consumers.

A. 0.27%
B. 2.70%
C. 0.10%
D. 1.00%


参考答案:  A


本题详细解析:
NPP from producers = 7800 (kJ9gb+/ 0j ezh;h6beyv n $m^{-2}yr^{-1}$)
Energy received by tertiary consumers (before respiration) = 21(kJ $m^{-2}yr^{-1}$)% flow of energy = ($\frac{21}{7800}$)×100 = 0.27%
Calculation for Option B is not correct.
Assuming a 10% transfer at every stage, the tertiary consumers would receive 0.1%, which is a general assumption but varies from ecosystem to ecosystem (Option C).
Option D assumes a 10% transfer but the calculation is not correct as it reaches the top of the food chain .

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