Although many hypotheses have been proposed to explain why some plant commun

游客2025-02-19  1

问题     Although many hypotheses have been proposed to explain why some plant communities are more susceptible than others to invasion by nonnative species, results from field studies have been inconsistent and no general theory of invasibility has yet emerged. However, a theory based on fluctuating resource availability could integrate most existing hypotheses and successfully resolve many of the apparently conflicting and ambiguous results of previous studies. The suggested theory is that a plant community becomes more susceptible to invasion whenever there is an increase in the amount of unused resources.
    The diversity in the range of resource-release mechanisms could partly explain the absence of consistent ecological correlates of invasibility. In particular, the theory predicts that there will be no necessary relationship between the species diversity of a plant community and its susceptibility to invasion, since nearcomplete exploitation can each occur in both species-rich and species-poor communities. Though Lonsdale found a positive association between species richness and invasion, this may arise from the tendency of diverse plant communities to be nutrient poor and therefore more responsive to the effects of human-caused influxes of nutrients. [br] It can be inferred that the author would most likely agree with which of the following assessments of the results from field studies

选项 A、many of the results contradicted predictions of susceptibility to invasion that are based on the availability of resources unused by the community.
B、if fluctuating resource availability were taken into account, many of the apparent inconsistencies among the results could be explained.
C、the apparent inconsistencies and ambiguities in the results are caused by trying to make them fit an inadequate general theory of invasibility.
D、no general theory of invasibility has emerged because none of the studies has been able to assess the degree of an invasion accurately.
E、the results tend to show a degree of susceptibility to invasion that is lower than would be expected given the prevalence in the wild of nonnative species.

答案 B

解析 作者的波动资源获得理论就是用来解决理论之间的矛盾的,这很明显是作者的态度,所以选项B正确。A项如果基于冗余资源做的预测和入侵性相矛盾,就意味着作者的理论不能用来解决理论矛盾,与作者态度相反。C项文中未提及an inadequate general theory of invasibility。D项文中未提及none of the studies has been able to assess the degree of an invasion accurately。E项文中未提及the prevalence in the wild of nonnative species。
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