Tides can deposit large quantities of dead vegetation within a salt marsh, smothering healthy plants and leaving a salt panne--a depression devoid of plants that tends to trap standing water--in the marsh's interior. Ecologist Kathryn Beheshti and colleagues found that burrowing crabs living within these pannes improve drainage by loosening the soil, leading the pannes to shrink as marsh plants move back in. At salt marsh edges, however, crab-induced soil loosening can promote marsh loss by accelerating erosion, suggesting that the burrowing action of crabs ______

Which choice most logically completes the text?

Question

Accepted Answer

may promote increases in marsh plants or decreases in marsh plants, depending on the crabs’ location.

Answer

can be beneficial to marshes with small pannes but can be harmful to marshes with large pannes.

Answer

tends to be more heavily concentrated in areas of marsh interiors with standing water than at marsh edges.

Answer

varies in intensity depending on the size of the panne relative to the size of the surrounding marsh.