Figure 7. Critical path for suspended and bedded sediments research. 
kinds of soils within these landscape delineations are particularly important. Secondly, 
fragmentation, storage, and hydrogeomorphic characteristics of streams and rivers need to be 
examined and classified at the watershed level as these factors influence the degree of flashiness 
of streams and rivers to precipitation, snowfall run-off, and groundwater inputs (Leopold et al. 
1964, Morisawa 1968, Mackin 1948). Ultimately these affect the timing of loadings, and 
quantity and type of sediment, not only to streams and rivers but to the receiving bodies into 
which they empty. The third step is classification by ecosystem type such as streams, rivers, 
coastal wetlands, estuaries, or near-shore zones. 
A discussion of the approaches anticipated for establishing stressor-response relationships for 
streams and rivers serves as a useful guide to the type of research anticipated in box lb. For 
bedded sediments in streams and rivers, it is likely that the expected levels of bedded fine 
sediment in relatively undisturbed streams are ecoregionally specific, depending upon natural 
climatic factors, topography, lithology, soil, and potential natural vegetation. It is also likely that 
the intensity of the response of sediment to anthropogenic disturbance will also be dependent 
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