Root systems can also play a role in slope stability.  An extensive root network on a hillslope can not only provide mechanical stabilization, but can also contribute to the formation of macroporous soil pipes to improve drainage, dissipating pore water pressure and reducing risk of slope failure (Ip, 2011, p. 2).  Root systems also enhance cohesion beyond the uppermost meter of soil, and can create desiccation cracks which provide channels for water seepage, increasing soil strength through moisture removal (p. 17).  Deforestation of headwater areas can have a profound impact not only on local conditions, but downstream as well. In addition to losing a soil anchor, removal of wood and vegetation also increases sediment production, much of which enters the stream network. This can result in choke points forming downstream, burying fields or damaging habitats, and an increased risk of slope failure from surface wash (Haigh et al, 2004, p. 51). Soil creep and surface erosion in gullies is also intensified by these activities, putting further sediment into the stream system. Left unchecked, this process will continue to pose risks to human development and ecological health.

            Good management practices must strike a balance between accommodating demand for development and resource extraction and environmental sustainability.  The concept of riparian management came about several decades ago, largely to protect fish habitat and water quality, but has since grown to include the increasing body of research around other ecosystem services, and the hydrologic and geological impacts both locally and downstream.  Current management schemes in British Columbia and the Pacific Northwest in the United States vary greatly, but a riparian buffer reserve of 30m has become common practice, largely in consideration of the large woody debris that forms salmonid habitats within headwater streams (Richardson, 2003, p. 19).  But is that sufficient to protect from other factors?  In Oregon’s Bureau of Land Management (BLM) Aquatic Conservation Strategy, no-cut stream buffers are established using biological and hydrological criteria.  Buffers are usually about 100m for fish-bearing streams, and 50m for non-fish bearing streams.  Thinning but not clear-cutting is permitted outside the buffers, and very rarely inside.  In contrast, privately-held timber under the Oregon Forest Practices Act dictates no-cut buffers on fish-bearing streams at about 6m, with some logging permitted from 6 to 30m.  Small, non-fish bearing streams in privately held lands may have a 0 to 6m buffer, with some logging permitted from 6 to 20m (Oregon Wild, 2012, p. 4).  Richardson (2003) asserts that riparian reserve widths from 60 to over 100m are needed to re-create densities of wildlife in areas that have already been logged (p. 19).  But riparian reserves in excess of 30m are not often found outside British Columbia and Oregon, and while smaller streams not requiring buffer zones may not have substantial salmonid populations, they can still supply organic matter to invertebrates downstream, supply clean water, and contribute to the overall viability of the watershed.