GRE课程
Questions 1 and 2 are based on this passage
Soil communities are dependent on plants for organic matter. Plants provide organic matter for soil communities through the decomposition of leaf litter, by oozing nutrients from roots, or through other methods of deposition of organic compounds into the soil environments. As a result of these diverse methods by which plants supply resources, unique soil communities form under different plant species and under plant communities that differ in composition. If a nonnative plant species invades an above-ground community of flora and fauna, it can alter links between the native above-ground community and the below-ground soil community. For example, an invading nonnative plant could alter the quantity of leaf litter production, which would alter nutrient contributions to the soil.
Consider each of the choices separately and select all that apply.
Which of the following statements about the connection between above-ground plants and below-ground soil communities can be inferred from the passage?
Because of the nature of the link between above-and below-ground communities, many soil communities are deficient in nutrients.
The extent to which soil communities are dependent on above-ground plants is extremely variable from one soil community to another.
Because different plants supply resources to soil communities in different ways, distinctive soil communities form under different plant communities.
Select one or more answer choices.
