Experimental Studies on the Resiliency of Floating Typha Mats in a Freshwater Marsh

Abstract

(1) This paper examines the phenology of Typha in floating mats, following drainage or seasonal burning or both, in marshes where water-level can be controlled, near the Bay of Fundy (New Brunswick, Canada). On both drained and flooded areas, four burning treatments (spring, summer, autumn and no burning) were superimposed in 1981. The fires were more intense than would occur naturally but we wished to establish resistance to change. (2) Drainage and subsequent burning in summer reduced the Typha standing crop, by the end of the vegetation period following the treatments, to 201% of that in the flooded, unburned treatment. (3) Typha survived the disturbance and no major shifts in species composition were observed. (4) The results suggest that the Typha floating mat is resilient and will recover quickly from the range of drying and burning regimes that could be imposed under the normal climatic conditions of the Bay of Fundy area. (5) It is hypothesized from the present short-term study that these flooded areas may move toward bog-like conditions in the absence of continued and severe human disturbance.