The frequency of occurrence of caterpillars also was higher on oceanspray (21%) and California hazel (36%) than on vine maple (16%), western hemlock (18%), bracken fern (11%), salal (9%), and sword fern (7%).
Bracken fern and oceanspray ranked highest in abundance and biomass of flies, but overlapping confidence intervals with vine maple, salal, and sword fern provided weak evidence of differences among these five species.
001) with bracken fern out-ranking all other plant species (Fig.
Plant species that ranked the highest for prey loads of arthropod taxa included oceanspray (caterpillars), California hazel (caterpillars and beetles), and bracken fern (combined prey taxa, flies, and Homoptera).
Bracken fern supports a high abundance of herbivores and their associated predators (Lawton 1976), especially where it grows in large, dense patches in sunlit areas (Doolittle 2000).
Our data indicate that broad-leaved deciduous shrubs and bracken fern provide optimal foraging habitat for breeding Wilson's Warblers because these plant species supported the highest abundance and biomass of foliage-dwelling arthropods [greater than or equal to] 2 mm in length, particularly caterpillars, flies, beetles, and Homoptera.
Bracken fern contains a chemical, ptaquiloside, that is known to be carcinogenic to mammals in high doses.
For bracken fern, never pick more than 50% of the stems in an area, and try to spread out your impact.