http://worldcat.org/entity/work/id/2496637329

Studies of water movement in vegetated and unvegetated littoral areas

Water circulation within aquatic plant beds and between plant beds and adjacent open water zones has important implications for both areas. Water movement mediates' the exchange of dissolved and suspended materials, including nutrients, dissolved oxygen, and suspended sediments. These exchanges are particularly important since they occur between areas dominated by different ecological life forms and processes. The littoral zone can be an important source of phosphorus (P) and other nutrients to the pelagic zone of lakes and reservoirs. Rooted submersed macrophytes mobilize sediment P by root uptake and senescence (Barko and Sman 1980; Carpenter 1980; Smith and Adams 1986). Macrophytes can also influence the release of nutrients from sediments by influencing pH and other environmental variables. Increasing pH in the water column caused by macrophyte photosynthesis stimulates P release from aerobic sediments through enhanced ligand exchange with iron hydroxide particles (Drake and Heaney 1987). Phosphorus and other nutrients mobilized by either of these mechanisms can then be carried from vegetated regions to nearby open water areas. By influencing water movements, macrophytes also influence sedimentation (James and Barko 1990; Petticrew and Kalff 1991), which in turn affects nutrient availability in the sediments. Typically, sedimentation rates are reduced within the center of macrophyte beds (Eakin and Barko 1989), although they can be elevated on the edges.

Open All Close All