Question

Vitousek hypothesized that high rates of primary production would result in the highest retention of nutrients in a given catchment. In support of this hypothesis, he found _______ amounts of nitrate in the _______ of catchments in old-growth forests than in forests at intermediate successional stages.

Answer 1

Lower amounts of nitrate were found in the streamwater of catchments in old-growth forests compared to those at intermediate successional stages, as old-growth forests are better at recycling and retaining nutrients due to their higher species diversity and mature ecosystem functions.

Step-by-step explanation:

Vitousek hypothesized that high rates of primary production would result in the highest retention of nutrients in a given catchment. In support of this hypothesis, he found lower amounts of nitrate in the streamwater of catchments in old-growth forests than in forests at intermediate successional stages. Old-growth forests, having reached the climax of ecological succession, are more effective at nutrient recycling and retention, likely due to their greater species diversity and complex ecosystem functions when compared to younger, less diverse forests. This efficient nutrient utilization reduces the leaching of nutrients such as nitrate into adjacent aquatic systems, which is a common phenomenon in areas with less mature vegetation cover, especially when human activities such as agriculture add nutrients to the soil.