Invasive Species Management Impacts on Native and Nonnative Ferns in an Urban Forest Spore Bank

摘要

Soil diaspore banks are important temporal refuges for forest plants and, although fern spore banks are prevalent, they are understudied in relation to forest management practices. As urbanization increases, understanding the dynamics of spore bank resources in urban forests becomes increasingly important. Urban forests tend to have a greater propensity for species invasions and present challenges to plant species management not encountered in other managed forests. We studied the impacts of Lonicera maackii removal on fern assemblages aboveground and in diaspore banks in an urban forest. The diaspore bank assemblage had greater richness and abundance of ferns compared to the aboveground assemblage. Six years after management implementation, plots from which L. maackii was removed had fewer fern species and fewer ferns in the spore bank than paired control plots in which the shrub was not removed. Two nonnative ferns typical of residential ornamental plantings and with characteristics of potentially invasive species were also found in control plot spore bank assemblages. Environmental variables including pH and amount of leaf litter contributed to differences between spore bank fern assemblage structure in removal and control areas. These results indicate the need for further studies of fern diaspore banks in managed, urban eastern forests.