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: Earth's carbon stor fnbsa7.2a5e4 -1c wbynedik+ ages & tzmupi-t,s 3dlr mg01g7p( )j(a r8ejpxg;v2annual flows in GT $yr^{-1}$
[Source: Adapted from NOAA Global Monitoring Laboratory (n.d.) Measuring & Analyzing Greenhouse Gases: Behind the Scenes. Retrieved March 20, 2022, from https ://gml.noaa.gov/outreach/behind_the_scenes/gases.html . Copyright under Public Domain]
Using the Figure, calculate a net flow of carbon.
A. Vegetation/soil releases 1 G T of carbon to the atmosphere each year.
B. Vegetation/soil absorbs 1 G T of carbon from the atmosphere each year.
C. Marine biota gain 11 G T of carbon each year.
D. Marine biota lose 11 G T of carbon each year.
参考答案: B
本题详细解析:
The diagram shows that soil/vegetation absorbs 123 GT of carbon from theu y xr0)hhf3 +vjc*mcl(jna2p 7.jys, atmosphere per year and releases 122 GT of carbon into the atmj)v 0rl3y x,fa(m* ccps. +jynjh7 hu2osphere per year. So, soil/vegetation absorbs a net of 123 GT−122 GT=1 GT of carbon per year.
Soil/vegetation gains 1 GT of carbon each year, rather than releasing 1 GT of carbon to the atmosphere (Option A). Marine biota gain a net total of 11 GT of carbon from the surface ocean but lose 11 GT of carbon to the intermediate/deep ocean so have a net flow of 0 GT of carbon per year. Therefore, marine biota neither gains
11 GT of carbon per year (Option C) nor loses 11 GT of carbon per year (Option D).
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