Alternative stable states of tidal marsh vegetation patterns and channel complexity

Salt marsh vegetation promotes efficient tidal channel networks

Tidal channel networks mediate the exchange of water, nutrients and sediment between an estuary and marshes. Biology feeds back into channel morphodynamics through the influence of vegetation on both flow and the cohesive strength of channel banks. Determining how vegetation affects channel networks is essential in understanding the biological functioning of intertidal ecosystems and their ecos...

Fire Feedbacks with Vegetation and Alternative Stable States

Positive feedbacks between vegetation and fire disturbance may lead to nonlinear ecosystem responses to variation in fire regime. We used a cellular automaton model of fire|vegetation dynamics based on pine savanna communities to explore the potential for fire|vegetation feedbacks to lead to ecological thresholds and abrupt transitions between alternate ecosystem states. We show that (i) ecosys...

Modelling of groundwater-vegetation interactions in a tidal marsh

Alternative fire-driven vegetation states

Traditionally, most vegetation patterns were thought to be driven by environmental conditions (Holdridge 1947; Whittaker 1975). The role of animals in determining patterns of vegetation has also long been recognized (Hairston et al. 1960; Terborgh et al. 2006), given that herbivores consume vegetation and, in turn, are controlled by carnivores and parasites. There is an increasing volume of lit...

Salt Marsh Tidal Channels

Salt marsh tidal channels are highly sinuous. For this project, field surveys and aerial photographs were used to characterize the planform of tidal channels at China Camp Marsh in the San Francisco Bay, California. To model the planform evolution, we assume that the topographic curvature of the channel centreline is a key element driving meander migration. Extraction of curvature data from a p...