94
3.4 Summary
The brief reviews of conditions in the Mississippi, Murray-Darling, Danube, and
Huanghe drainage basins illustrate how multiple simultaneous and prolonged
human alterations can have cumulative effects on water quality, river biota, the stability and productivity of deltas and nearshore regions, and other ecosystem services. Recognizing that multiple and diverse alterations influence a particular river
ecosystem is critical for effective management because it facilitates understanding
that, although management may target a particular factor such as altered flow regime
for a desired end such as restoration of water quality, the effectiveness of this targeted management may be limited by other alterations such as continued high inputs
of nitrates from upland areas within the watershed in which land cover was historically altered.
The four drainage basins highlighted in this chapter are not unique in their history of human activities and consequent changes in river ecosystems. As of 2005,
only a few of the large river basins around the world were relatively unaffected by
flow regulation. These rivers, which tend to be in high- and low-latitude regions
rather than in the temperate latitudes (Nilsson et al. 2005a), are in many cases slated
for extensive development. At the same time, however, efforts to restore and maintain rivers as ecosystems are increasing within the temperate-latitude river basins
that have already been highly altered by people. The next chapter reviews some of
these efforts to restore rivers as highly functional ecosystems.
References
Aarts BGW, van den Brink FWB, Nienhuis PH (2004) Habitat loss as the main cause of the slow
recovery of fish faunas of regulated large rivers in Europe: the transversal floodplain gradient.
River Res Appl 20:3–23
Allison GB, Cook PG, Barnett SR, Walker GR, Jolly ID, Hughes MW (1990) Land clearance and
river salinization in the western Murray basin, Australia. J Hydrol 119:1–20
Arthington AH, Pusey BJ (2003) Flow restoration and protection in Australian rivers. River Res
Appl 19:377–395
Auble GT, Friedman JM, Scott ML (1994) Relating riparian vegetation to present and future
streamflows. Ecol Appl 4:544–554
Baillie BR, Davies TR (2002) Influence of large woody debris on channel morphology in native
forest and pine plantation streams in the Nelson region, New Zealand. N Z J Mar Freshw Res
36:763–774
Baker DW, Bledsoe BP, Albano CM, Poff NL (2011) Downstream effects of diversion dams on
sediment and hydraulic conditions of Rocky Mountain streams. River Res Appl 27:388–401
Baxter CV, Fausch KD, Murakami M, Chapman PL (2007) Invading rainbow trout usurp a terrestrial prey subsidy from native charr and reduce their growth and abundance. Oecologia
153:461–470
Beckett DC, Green BW, Thomas SA, Miller AC (1996) Epizoic invertebrate communities on upper
Mississippi River unionid bivalves. Am Midl Nat 135:102–114
Bednarek AT (2001) Undamming rivers: a review of the ecological impacts of dam removal.
Environ Manag 27:803–814
3 Human Alterations of Rivers
3.4 Summary
The brief reviews of conditions in the Mississippi, Murray-Darling, Danube, and
Huanghe drainage basins illustrate how multiple simultaneous and prolonged
human alterations can have cumulative effects on water quality, river biota, the stability and productivity of deltas and nearshore regions, and other ecosystem services. Recognizing that multiple and diverse alterations influence a particular river
ecosystem is critical for effective management because it facilitates understanding
that, although management may target a particular factor such as altered flow regime
for a desired end such as restoration of water quality, the effectiveness of this targeted management may be limited by other alterations such as continued high inputs
of nitrates from upland areas within the watershed in which land cover was historically altered.
The four drainage basins highlighted in this chapter are not unique in their history of human activities and consequent changes in river ecosystems. As of 2005,
only a few of the large river basins around the world were relatively unaffected by
flow regulation. These rivers, which tend to be in high- and low-latitude regions
rather than in the temperate latitudes (Nilsson et al. 2005a), are in many cases slated
for extensive development. At the same time, however, efforts to restore and maintain rivers as ecosystems are increasing within the temperate-latitude river basins
that have already been highly altered by people. The next chapter reviews some of
these efforts to restore rivers as highly functional ecosystems.
References
Aarts BGW, van den Brink FWB, Nienhuis PH (2004) Habitat loss as the main cause of the slow
recovery of fish faunas of regulated large rivers in Europe: the transversal floodplain gradient.
River Res Appl 20:3–23
Allison GB, Cook PG, Barnett SR, Walker GR, Jolly ID, Hughes MW (1990) Land clearance and
river salinization in the western Murray basin, Australia. J Hydrol 119:1–20
Arthington AH, Pusey BJ (2003) Flow restoration and protection in Australian rivers. River Res
Appl 19:377–395
Auble GT, Friedman JM, Scott ML (1994) Relating riparian vegetation to present and future
streamflows. Ecol Appl 4:544–554
Baillie BR, Davies TR (2002) Influence of large woody debris on channel morphology in native
forest and pine plantation streams in the Nelson region, New Zealand. N Z J Mar Freshw Res
36:763–774
Baker DW, Bledsoe BP, Albano CM, Poff NL (2011) Downstream effects of diversion dams on
sediment and hydraulic conditions of Rocky Mountain streams. River Res Appl 27:388–401
Baxter CV, Fausch KD, Murakami M, Chapman PL (2007) Invading rainbow trout usurp a terrestrial prey subsidy from native charr and reduce their growth and abundance. Oecologia
153:461–470
Beckett DC, Green BW, Thomas SA, Miller AC (1996) Epizoic invertebrate communities on upper
Mississippi River unionid bivalves. Am Midl Nat 135:102–114
Bednarek AT (2001) Undamming rivers: a review of the ecological impacts of dam removal.
Environ Manag 27:803–814
3 Human Alterations of Rivers