What combination of factors determines whether a lake's recovery after disturbance returns to pre-disturbance conditions or shifts to an alternative stable state?

• A. Reservoir size and connectivity alone determine recovery outcomes
• B. Ongoing nutrient status alone determines recovery outcomes
• C. Ongoing stressors alone determine recovery outcomes
• D. All of the above

Answer: (D)

Recovery after a disturbance is shaped by how the system balances physical scale, nutrient inputs, and ongoing pressures. The size of the lake and how connected it is to other water bodies influence resilience and the chance for recolonization; a larger, more connected lake can better dampen disturbances and rebound, but those same features can also propagate effects if stressors aren’t reduced. The nutrient status sets the level of primary production and creates feedbacks—high nutrients can lock in more productive, turbid conditions that favor an alternative stable state unless inputs are lowered and feedbacks are interrupted. Ongoing stressors such as climate effects, pollution, or hydrological changes continually push the system, making it harder to return to its previous state and increasing the likelihood of settling into a different regime. Because recovery outcomes depend on the interaction of these physical, chemical, and stressor factors, all of them together determine whether the lake returns to pre-disturbance conditions or shifts to an alternative stable state.