Leaves of B. oneidense begin to develop in May and sporangia mature in late September. Leaves persist through the winter and usually remain green. The plants are tolerant of human disturbances such as lumbering as long as some trees are left to provide shade. It is highly probable that B. oneidense no longer occurs at many of these historic sites that are in areas where suburban development has occurred. Many other sites, however, are in areas where suburban development may have destroyed the habitat.
Many historic localities are in or near fast-growing suburban communities.
Alteration of the water regime also is a threat. The intermittent wetness, characteristic of its habitats, presumably prevents competition from species better adapted to perennially dryer or wetter conditions. Some human disturbances may even be beneficial. Populations are widely scattered, making it less likely that spores will be available for recolonization. The presence or absence of plants at historic sites should be verified and all sites should be periodically monitored for population sizes.