FIGURE 1.1 Landscapes at Earths surface host a suite of interconnected landforms and processes that can remain stable for long periods of time and can also respond rapidly to changes in climate or land use. In this view of a recently deglaciated valley in the Juneau Icefield, Alaska, surface features comprise hillslopes, rock falls and slides, glaciers (in the far distance, upper right corner of the image), alluvial fans, streams, wetlands, and biota. Integral processes less visible than the landforms and land cover include weathering, soil formation, climate, surface and groundwater flow, nutrient fluxes, and tectonics. SOURCE: Photograph courtesy of Dorothy Merritts, Franklin and Marshall College, Lancaster, Pennsylvania.

FIGURE 1.1 Landscapes at Earth’s surface host a suite of interconnected landforms and processes that can remain stable for long periods of time and can also respond rapidly to changes in climate or land use. In this view of a recently deglaciated valley in the Juneau Icefield, Alaska, surface features comprise hillslopes, rock falls and slides, glaciers (in the far distance, upper right corner of the image), alluvial fans, streams, wetlands, and biota. Integral processes less visible than the landforms and land cover include weathering, soil formation, climate, surface and groundwater flow, nutrient fluxes, and tectonics. SOURCE: Photograph courtesy of Dorothy Merritts, Franklin and Marshall College, Lancaster, Pennsylvania.

Other than a basic goal of explaining the form, composition, and evolution of landscapes, why might questions about Earth surface processes near a stream, or similar types of questions posed along a coastline or in a fragile arctic landscape, matter? At present, we are unable to make confident, process-oriented predictions of how landscapes respond to change. If climate change brings, for example, an increase in rainfall, will soils deliver more or fewer nutrients to groundwater and streams? If humans remove river dams and release the sediment stored behind them, as well as the nutrients and pollutants bound to the sediments, how will downstream fish habitats, estuaries, and coastal marshes be affected? Will the extra sediment stop the retreat of receding beaches, or will the sediment wash out to sea? Because of these and other such critical questions, society has become concerned about landscapes “on the edge” of potentially detrimental and irreversible change and has



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