Fig. 5.

Experimental results. (A) The predation rate on mussel aggregations deployed on grazed (blue) and ungrazed (green) creek borders and marsh platforms, reported as the percent of each mussel aggregation consumed after 4 wk (data are shown as the mean ± SE of eight aggregations per creek type and zone; data are pooled across three sites). (B) Classification tree analysis of predation rates on mussels (dark brown icons) and snails (light brown icons) revealed a hierarchy of factors controlling benthic macroinvertebrate survival. For both mussels and snails, predator exclusion (i.e., full cage vs. control and elevated cage) explained the greatest degree of variance in the data, followed by creek type (i.e., ungrazed vs. grazed) and then zone (i.e., platform vs. border).