Responses of a Willow (Salix caroliniana Michx.) Community to Roller-Chopping

Approximately eight hectares of shrub swamp wetland, primarily consisting of willow (Salix caroliniana Michx.), were roller-chopped to test the efficacy of this management technique in returning the plant community to one dominated by herbaceous species. Roller-chopping caused severe disturbance to the treatment area. Few willows were left standing and a majority of trees were uprooted entirely. Three months following chopping, limited re-sprouting of willow was observed. However, by the following March, no live willows were found in the treatment area. Willow remained absent for three years post-treatment. Hydrologic conditions may have influenced willow mortality through drought-induced stress and subsequent inundation in the treatment area. In contrast, these hydrologic conditions did not appear to affect willows in the control area. Following the elimination of willow, herbaceous plant species re-colonized the treatment areas, increasing in richness and abundance. Free-floating plants became the dominant species in the newly opened areas. Gradually, free-floaters became less important while rooted emergents, such as graminoids and forbs, became more abundant. This study indicates that, under dry conditions followed by flooding, roller-chopping can be an effective method of willow control. However, utilization of heavy equipment may alter topography, compact soil, and affect drainage patterns. Therefore, managers should exercise caution when applying this technique.