FOREST AND WETLAND EXPANSION IN THE MID TO LATE DEVONIAN

Mid to Late Devonian landscapes show the emergence and expansion of new plant groups defined by innovations of growth and reproductive motifs. Landscapes became more fully and densely covered as these motifs both modified and helped plants exploit new ecological possibilities.

New root biology (perennial roots & adventitious rootlets of lignophytes and hollow root cortex of lycophytes) aided long-term habitat modification and occupation and exploitation of drier floodplains as well as flooded, anoxic soils of wetlands. Thickening growth aided plant longevity by providing more tissue for nutrient storage, conductive and protective tissue, and enhanced biomechanical stability needed for height growth. Increased longevity contributed to greater incumbency that favored grove formation. Dispersal of reproductive propagules (spores, pollen, ovules, and seeds) was positively affected by taller growth and habitat specialization.

Increased plant litter and its fluvial dispersal thus increased land-based trophic interactions throughout the Mid and Late Devonian.