Salt marsh restoration teams often transplant cordgrass shoots at uniform intervals, reasoning that spacing the shoots apart minimizes competition among them. Ecologist Marisol Vega instead proposes transplanting the same number of shoots in compact clusters separated by unvegetated gaps. Vega acknowledges that competition may initially slow the growth of individual shoots within each cluster. However, she argues that clusters can reduce local wave energy and capture sediment, gradually making the intervening gaps suitable for cordgrass rhizomes to enter. Vega therefore predicts that on erosion-prone shorelines, clustered plantings will produce more continuous vegetative cover over several years than uniformly spaced plantings will.
Which finding, if true, would most directly support Vega’s prediction?
For a command-of-evidence question, break the claim into its essential parts: the comparison being made, the conditions that must be controlled, the predicted result, and any proposed process. Then choose the finding that addresses all of those parts while avoiding confounding differences such as unequal starting quantities.
Hints
Separate the short-term and long-term claims
Notice that the ecologist allows for an early disadvantage but predicts a different result after several years.
Check the comparison
Prefer evidence that keeps the initial number of shoots and the shoreline conditions comparable across planting designs.
Consider the proposed process
Ask whether the finding shows not only a change within the original clusters but also expansion into the spaces between them.
Step-by-step Explanation
Identify the complete prediction
Vega predicts that although clustered shoots may grow more slowly at first, clusters will retain sediment, permit growth into the gaps, and ultimately create more continuous cover than uniform spacing on erosion-prone shorelines.
Look for a controlled and relevant comparison
The strongest evidence should compare erosion-prone plots receiving equal numbers of shoots so that planting arrangement, rather than the starting quantity of cordgrass or shoreline conditions, explains the result.
Match the long-term result and proposed process
The correct finding reports an initial disadvantage for clustered plots followed by less bare shoreline after five years. It also indicates that the gaps rose before rhizomes colonized them, matching the process Vega proposes.