Landscape gradients and patchiness in riparian vegetation on a Middle Pennsylvanian braided-river plain prone to flood disturbance (Nyrany Member, Central and Western Bohemian Basin, Czech Republic)
Abstract
Spatial heterogeneity and community ecology of riparian vegetation preserved in fluvial deposits of the upper Moscovian Nýřany Member, Central and Western Bohemia is reconstructed. Taphonomic observations and multivariate analysis of (par)autochthonous megafloral assemblages reveal that vegetation comprised a collage of low-diversity communities, with patchiness at local and regional scales.
Non-metric multi-dimensional scaling exposes habitat partitioning between different plant groups, which were organized along ecological gradients controlled by the drainage and stability of substrates. Better-drained and stable channel margins supported long-lived siteoccupiers, such as cordaitaleans and monospecific stands of medullosalean pteridosperms.
Pioneering vegetation comprising fast-growing, opportunistic taxa (ferns and sphenopsids), was most common on wetter, shifting substrates of frequently flooded abandoned channels, low-lying floodplains, and lake margins whereas lycopsids dominated swamps.