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descriptions, such as "associated with water courses"..., to tecluucal and detailed descriptions for <br />specific areas ". They cite a recent proposed defiiution that suggest riparian zones are, "three <br />dimensional ecotones of interaction that include terrestrial and aquatic ecosystems, that extend <br />down into the groundwater, up above the canopy, outward across the floodplain, up the near- <br />slopes that drain to the water, laterally into the terrestrial ecosystem, and along the water course <br />at a variable width". Fischer, Martin, and Fischenich (2000) define riparian zones as <br />transitional areas between aquatic and upland terrestrial habitats and although not always well <br />defined, they generally can be described as long strips of vegetation adjacent to streams, rivers, <br />lakes, reservoirs, and other inland aquatic systems that affect or are affected by the presence of <br />water. These zones typically comprise a small percentage of the landscape, yet they frequently <br />harbor a disproportionately high number of wildlife species and "perform a disparate number of <br />ecological functions when compared to most upland habitats" (Fischer, Martin, and Fischeiuch , <br />2000). <br />Throughout the southwest, it is well lalown how important riparian corridors are to water quality, <br />and fisheries. Several factors or "ecological functions" can have very different effects on <br />riparian ecosystems within a given reach or entire drainage basin. One of these "ecological <br />fiulctions" which can have a significant impact on cold water fisheries is temperature. Poole and <br />Berman (2000), state that channel water temperature is deternuned by "the interactions between <br />external drivers of stream temperature and the internal stn~cture of the integrated stream <br />system". They also state other factors can also affect stream temperature. The primary <br />influences are climate "(such as air temperature and wind speed), stream morphology, <br />groundwater influences, and riparian canopy condition". Other indicators of water quality <br />include the study of macro invertebrates, which can serve as indicators of the general health of <br />the river. <br />Elevation gradients will also have an effect of these factors. Gradients have been shown to show <br />direct correlations between age class distribution of many riparian woody plant species. <br />Coclanan and Pieper, (1997). Land use and land cover changes may also have significant <br />impacts on these systems. Different lands and cover types help predict "water chemistry aquatic <br />invertebrate community composition and biotic integrity of fish", Gergel, et al., (1999). <br />Sometimes these challenges are also the result of surrounding uses of the land. Harding et al, <br />(1998), clearly states this in historical context by saying, ecologists have "long recognized the <br />strong dependence of streams on the surrounding terrestrial environment and these zones are <br />influenced by stream hydrology, substrate characteristics, temperature regimes, and water <br />chemistry, which in turn affect all trophic levels". <br />10 <br />