What natural influences affect riparian zones?
Water Supply is the major factor that regulates the growth of riparian vegetation. Flood waters transport nutrients, sediment and new seeds from upstream. Floods also strip away larger, established vegetation and allow new seedlings to establish.
Soil type in the riparian zone influences the amount of water and nutrients available. Organic-rich soil holds water and provides abundant nutrients to plays, without releasing these nutrients to the water. We can expect to find denser vegetation in these soils than in a gravely soil with little water-holding capacity and few nutrients.
Topography, or the shape of the land, affects the location and abundance of plants in the riparian zone.
Climate affects the appearances of riparian zones. In the deserts riparian zones are "green oases" in sparse, dry surroundings. Where precipitation is more abundant, like in the mountains, the upland vegetation remains relatively lush.