Text 1: Biologist Smit argues that the introduction of beavers to a degraded watershed is a low-cost ecological intervention. As beavers build dams, they slow water flow, raise water tables, and create wetlands that filter pollutants and support biodiversity. Several Western U.S. restoration projects have produced striking results.
Text 2: Biologist Lin agrees that beavers have ecological benefits but cautions against generalizing from the success cases. In the wrong location, beaver dams flood roads, undermine bridges, and alter habitats in ways that conflict with human land use. Beaver-based restoration, Lin argues, requires careful site selection, not enthusiastic deployment.
The authors most clearly disagree about
- A
whether beavers can affect ecosystems.
- B
whether beavers build dams.
- Ccheck_circle
whether beaver-based restoration should be deployed broadly without site-specific planning.
- D
whether wetlands provide ecological benefits.
Explanation
Both accept beavers' ecological role; they differ on deployment strategy. B captures the disagreement. A, C, and D are points of agreement.