[单选题]
The following image is a graph obtained by plo
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(k um2 3qvwyd9m 6niv9lues for net primary productivity (x-axis) and the biomass of herbivores (y-axis). The black dots represent one biome and the grey dots
mn 3vdkm9 6uw(q9vy2i represent another biome.
The x-axis shows the increasing net primary productivity of biomes, and the y-axis shows the increasing biomass of herbivores. Which of the following choices correctly identifies the biomes represented in the graph above?
A. The black circle is Taiga ; The grey circle is Desert
B. The black circle is Rainforest ; The grey circle is Savanna
C. The black circle is Savanna ; The grey circle is Tundra
D. The black circle is Tundra ; The grey circle is Savanna
参考答案:
D
本题详细解析:
Explanation:
The net primary productivities of the taiga, tundra and desert biomes are relatively lower than the rainforest and savanna biomes. Lower net primary productivity leads to lower secondary productivity. The biomass of the herbivores is therefore lower in the taiga, tundra and desert biomes compared to the savanna and rainforest biomes.
Choice D is the correct choice because the tundra has lower net primary productivity so therefore supports a lesser biomass of herbivores. The savanna has vast dry grasslands and therefore more primary productivity overall so can support a larger biomass of herbivores.
Deserts tend to have the lowest productivity of these biomes due to limited water availability, and rainforests have the highest productivity due to their abundant rainfall and sunlight. Choices A and B are therefore incorrect. The other ecosystems fall in between based on factors like climate, nutrient availability, and plant diversity. The next lowest net productivity tends to be seen in the tundra, then the taiga. The savannah has a high net productivity, but it is lower than rainforests. Choice C is therefore incorrect.
