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  3. Seeding a forest with nonnative species after a fire can impede native plant regeneration and spread invasive species in vulnera

Seeding a forest with nonnative species after a fire can impede native plant regeneration and spread invasive species in vulnera

admin2021-03-28  22
问题     Seeding a forest with nonnative species after a fire can impede native plant regeneration and spread invasive species in vulnerable fire-affected soils. Moreover, native seed sources are almost always sufficient for early nature reestablishment of native species, so planting should be considered only when natural regeneration is unlikely. Replanting dense stands of fast-growing conifers—a common postfire management practice—truncates the biologically rich early stage of ecological succession and can increase the severity of future fires. Other treatments should be carefully scrutinized for their potential to spread noxious weeds. For instance, straw much applied extensively to reduce erosion after the 2002 Hayman Fire in Colorado was contaminated with cheatgrass, an invasive grass difficult to control or eradicate once established.
The passage implies which of the following about native plant regeneration in forests after a fire?
选项 A、It is hampered by the changed nature of the fire-affected soils.
B、It will generally occur without the human interventions of reseeding or replanting.
C、The likelihood of its success increases when forest managers have on hand a good supply of native seed sources.
D、Native plants will inevitably have to compete with nonnative plants.
E、The earlier nature reestablishment occurs, the more complete it will
答案B
解析 根据第二句，当地种子的资源几乎总是足够的，因此不受到人类的影响也可以发生自然再生。选项B正确。A项文章第一句确实提到土壤性质发生了变化，但是没说自然再生的进程会受到土壤性质的变化的阻碍。
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