Control problematic plants (multiple interventions): freshwater marshes or swamps
Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
Background information and definitions
This section considers control of problematic plants using >3 separate interventions at once, such that it is difficult to attribute outcomes to any single specific intervention. Where three or fewer interventions have been used together in a study, it is included as evidence for each intervention elsewhere in the synopsis (whilst explicitly noting the use of multiple interventions in each summary paragraph).
For this section, “vegetation” refers to overall or non-target vegetation. Studies that only report responses of target problematic plants have not been summarized.
Supporting evidence from individual studies
A controlled study in 1987–2004 in an ephemeral freshwater marsh in Costa Rica (Trama et al. 2009) reported that controlling invasive southern cattail Typha domingensis with multiple interventions reduced the total vegetated area and vegetation cover, but increased plant species richness. Unless specified, statistical significance was not assessed. After approximately 15–17 years, a managed plot (where cattail had been controlled) contained less live vegetation overall than an unmanaged plot. This was true for the total area of live vegetation (managed: 28–85%; unmanaged: 98–100%) and cover of live vegetation along transects (managed: 35–91%; unmanaged: 88–100%). Abundance varied across seasons. The managed plot also contained less cattail – both in terms of the total area (managed: 9–24% of plot; unmanaged: 63–66% of plot) and cover along transects (managed: 5–10%; unmanaged: 75–100%). Finally, the managed plot contained more plant species in total (managed: 59; unmanaged: 20) and had significantly greater plant species richness (managed: 13; unmanaged: 4 species/300 m2 transect). Methods: Two 80-ha plots were established in a cattail-dominated marsh. Cattail stands were managed in one of the plots: with multiple experimental interventions from 1987 (including cutting by hand, mowing, physical damage, grazing and burning, alone and in combination) then by physical damage alone from September 2002 (driving over it in a tractor with large paddle wheels). Water supply was also restored to both plots in July 2002. Vegetation stands were mapped from aerial photographs or satellite images taken in November 2002 (wet season) and March 2003 (dry season). Detailed vegetation surveys, along six 25 x 2 m transects/plot, were carried out between August 2003 and July 2004.Study and other actions tested