, Volume 111, Issue 1–3, pp 125–138 | Cite as

Human activities directly alter watershed dissolved silica fluxes



Controls on chemical weathering, such as bedrock geology, runoff, and temperature, are considered to be the primary drivers of Si transport from the continents to the oceans. However, recent work has highlighted terrestrial vegetation as an important control over Si cycling. Here we show that at the regional scale (Southern New England, USA), land use/land cover (LULC) is an important variable controlling the net transport of Si from the land to the sea, accounting for at least 40% of dissolved Si (DSi) fluxes. A multiple linear regression model using average DSi fluxes from 25 rivers (>2,300 observations) shows the percent forest cover, as well as development and agricultural land use, to be significant (p < 0.05) drivers of DSi flux. This was true regardless of watershed size and lithology. Furthermore, forest cover is significantly negatively correlated, while development is significantly positively correlated, with Si concentrations and fluxes. We hypothesize that these relationships are due to several mechanisms, specifically the ability of terrestrial vegetation to store large amounts of Si within its biomass, the altered watershed hydrology that accompanies LULC change, and the capability of urban regions to serve as sources of Si to aquatic systems. Thus, we conclude that anthropogenic activities may be directly perturbing the global Si cycle through land use change and we offer a conceptual model which highlights a new approach to understanding the non-geochemical controls on Si fluxes.


Dissolved silica Land use/land cover Lithology Rivers New England Terrestrial vegetation 


  1. Alig RJ, Kline JD, Lichtenstein M (2004) Urbanization on the US Landscape: looking ahead in the 21st century. Landsc Urban Plan 69:219–234CrossRefGoogle Scholar
  2. Anderson DM, Glibert PM, Burkholder JM (2002) Harmful algal blooms and eutrophication: nutrient sources, composition, and consequences. Estuaries 24:704–726CrossRefGoogle Scholar
  3. Bartoli F (1983) The biogeochemical cycle of silicon in two temperate forest ecosystems. Environ Biogeochem Ecol Bull 35:469–476Google Scholar
  4. Bartoli F, Wilding LP (1980) Dissolution of biogenic opal as a function of its physical and chemical properties. Soil Sci Soc Am J 44:873–878CrossRefGoogle Scholar
  5. Beusen AHW, Bouwman AF, Durr HH, Dekkers ALM, Hartman J (2009) Global patterns of dissolved silica export to the coastal zone: results from a spatially explicit global model. Glob Biogeochem Cyc 23:GB0A02. doi:10.1029/2008GB003281
  6. Bluth GJ, Kump LR (1994) Lithological and climatologic controls of river chemistry. Geochim Cosmochim Acta 58:2341–2359CrossRefGoogle Scholar
  7. Clark JF, Simpson HJ, Bopp RF, Deck B (1992) Geochemistry and loading history of phostphate and silicate in the Hudson estuary. Estuar Coast Shelf Sci 34:213–233CrossRefGoogle Scholar
  8. Clymans W, Struyf E, Govers G, Vandevenne F, Conley DJ (2011) Anthropogenic impact on amorphous silica pools in temperate soils. Biogeosciences 8:2281–2293CrossRefGoogle Scholar
  9. Conley DJ (1997) Riverine contribution of biogenic silica to the oceanic silica budget. Limnol Oceanogr 42:774–777Google Scholar
  10. Conley DJ (2002) Terrestrial ecosystems and the global biogeochemical silica cycle. Glob Biogeochem Cyc 16:68.1–68.7CrossRefGoogle Scholar
  11. Conley DJ, Stalnacke P, Pitkanem H, Wilaner A (2000) The transport and retention of dissolved silicate by rivers in Sweden and Finland. Limnol Oceanogr 45:1850–1853CrossRefGoogle Scholar
  12. Conley DJ, Likens GE, Buso DC, Saccone L, Bailey SW, Johnson CE (2008) Deforestation causes increased dissolved silicate losses in the Hubbard brook experimental forest. Glob Change Bio 14:2548–2554Google Scholar
  13. Cornelis JT, Ranger J, Iserentant A, Delvaux B (2010) Tree species impact the terrestrial cycle of silicon through various uptakes. Biogeochemistry 97:231–245CrossRefGoogle Scholar
  14. Danielsson A, Papush L, Rahm L (2008) Alterations in nutrient limitations—scenarios of a changing baltic sea. J Mar Sys 73:263–283CrossRefGoogle Scholar
  15. Derry LA, Kurtz AC, Ziegler K, Chadwick OA (2005) Biological control of terrestrial silica cycling and export fluxes to watersheds. Nature 433:728–731CrossRefGoogle Scholar
  16. Drever J (1994) The effect of land plants on weathering rates of silicate minerals. Geochim Cosmochim Acta 58:2325–2332CrossRefGoogle Scholar
  17. Dyke AS, Prest VK (1987) Late Wisconsinan and Holocene history of the laurentide ice sheet. Geogr Phy Quat 41:237–263Google Scholar
  18. Epstein E (1994) Review: the anomaly of silicon in plant biology. Proc Natl Acad Sci 91:11–17CrossRefGoogle Scholar
  19. Epstein E (1999) Silicon. Ann Rev Plant Physiol 50:641–664CrossRefGoogle Scholar
  20. Foley et al (2005) Global consequences of land use. Science 309:570–574CrossRefGoogle Scholar
  21. Foster DR, Aber JD (2004) Forests in time; environmental consequences of 1,000 years of land use change in New England. Yale University Press, New HavenGoogle Scholar
  22. Foster DR, Motzkin G, Slater B (1998) Land-use history as long-term broad-scale disturbance: regional forest dynamics in central New England. Ecosystems 1:96–119CrossRefGoogle Scholar
  23. Fraysse F, Pokrovsky OS, Schott J, Meunier J-D (2009) Surface chemistry and reactivity of plant phytoliths in aqueous solutions. Chem Geol 258:197–206CrossRefGoogle Scholar
  24. Fulweiler RW, Nixon SW (2005) Terrestrial vegetation and the seasonal cycle of dissolved silica in a southern New England coastal river. Biogeochemistry 74:115–130CrossRefGoogle Scholar
  25. Gaillardet J, Dupre B, Louvat P, Allegre CJ (1999) Global silicate weathering and CO2 consumption rates deduced from chemistry of large rivers. Chem Geol 159:3–30CrossRefGoogle Scholar
  26. Galloway J (1998) The global nitrogen cycle: changes and consequences. Environ Pollut 102:15–24CrossRefGoogle Scholar
  27. Gregory KJ (2006) The human role in changing river channels. Geomorphology 79:172–191CrossRefGoogle Scholar
  28. Hobbs F, Stoops N (2002) Demographic trends in the 20th Century. U.S. census bureau census 2000 special reports—series CENSR-4. US Government Printing Office, Washington, DCGoogle Scholar
  29. Hodgkins GA, Dudley RW, Huntington TG (2003) Changes in the timing of high river flows in New England over the 20th Century. J Hydrol 278:244–252CrossRefGoogle Scholar
  30. Huang S, Pollack HN, Shen P-Y (2000) Temperature trends over the past five centuries reconstructed from borehole temperatures. Nature 403:756–758CrossRefGoogle Scholar
  31. Humborg C, Conley DJ, Rahm L, Wulff F, Cociasu A, Ittekkot V (2000) Silicon retention in river basins: far-reaching effects of biogeochemistry and aquatic food webs in coastal marine environments. Ambio 29:45–50Google Scholar
  32. Humborg C, Smedberg E, Blomqvist S, Morth C-M, Brink J, Rahm L, Danielsson A, Sahlberg J (2004) Nutrient variations in boreal and subartic Swedish rivers: landscape control of land-sea fluxes. Limnol Oceangr 49:1871–1883CrossRefGoogle Scholar
  33. Humborg C, Pastuszak M, Aigars J, Siegmund H, Morth C-M, Ittekkot V (2006) Decreased silica land-sea fluxes through damming in the Baltic Sea catchment: significance of particle trapping and hydrological alterations. Biogeochemistry 77:265–281CrossRefGoogle Scholar
  34. Huntington TG, Hodgkins GA, Keim BD, Dudley RW (2004) Changes in the proportion of precipitation occurring as snow in New England (1949–2000). J Climate 17:2626–2636CrossRefGoogle Scholar
  35. Ittekkot V, Unger D, Humborg C, Tac AN (2006) The silicon cycle. Island Press, Washington, DCGoogle Scholar
  36. Jansen N, Hartmann J, Lauerwald R, Durr HH, Kempe S, Loos S, Middelkoop H (2010) Dissolved silica mobilization in the conterminous USA. Chem Geol 270:90–109CrossRefGoogle Scholar
  37. Johnson BL, Richardson WB, Naimo TJ (1995) Past, present, and future concepts in large river ecology. BioScience 45:134–141CrossRefGoogle Scholar
  38. Leapold LB (1968) Hydrology for urban land planning—a guidebook on the hydrology effects of urban land use. United States Geologic Survey, Washington, DCGoogle Scholar
  39. Nelson DM, Tregeur P, Brzezinski MA, Leynaert A, Queguiner R (1995) Production and dissolution of biogenic silica in the oceans: revised global estimates, comparison with regional data and relationships to biogenic sedimentation. Glob Biogeochem Cyc 9:359–372CrossRefGoogle Scholar
  40. Officer CB, Ryther JH (1980) The possible importance of silicon in marine eutrophication. Mar Ecol Prog Ser 3:83–91CrossRefGoogle Scholar
  41. Randolph J (2004) Environmental land use planning and management. Island Press, Washington, DCGoogle Scholar
  42. Sferratore A, Garnier J, Billen G, Conley DJ, Pinault S (2006) Diffuse and point sources of silica in the Seine River watershed. Environ Sci Tech 40:6630–6635CrossRefGoogle Scholar
  43. Street-Perrott FA, Barker PA (2008) Biogenic silica: a neglected component of the coupled global continental biogeochemical cycles of carbon and silicon. Earth Surf Proc Landforms 33:1436–1457CrossRefGoogle Scholar
  44. Struyf E, Conley DJ (2009) Silica: an essential nutrient in wetland biogeochemistry. Front Ecol Environ 7:88–94CrossRefGoogle Scholar
  45. Struyf E and Conley DJ (2011) Emerging understanding of the ecosystem silica buffer. Biogeochem (in press)Google Scholar
  46. Struyf E, Van Damme S, Gribsholt B, Middelburg JJ, Meire P (2005) Biogenic silica in tidal freshwater marsh sediments and vegetation (Schelde estuary Belgium). Mar Ecol Prog Ser 303:51–60CrossRefGoogle Scholar
  47. Struyf E, Smis A, Van Damme S., Garnier J, Govers G, Van Wesemael B, Conley DJ, Batelaan O, Frot E, Clymans W, Vandevenne F, Lancelot C, Goos P, Meire P (2010) Historical land use change has lowered terrestrial silica mobilization. Nat Commun. doi:10.1038/ncomms1128
  48. Tipper ET, Bickle MJ, Galy A, West AJ, Pomiès C, Chapman HJ (2006) The short term climatic sensitivity of carbonate and silicate weathering fluxes: insight from seasonal variations in river chemistry. Geochim Cosmochim Acta 70:2737–2754CrossRefGoogle Scholar
  49. Treguer P, Nelson DM, van Bennekom AJ, DeMaster DJ, Leynaert A, Queguiner B (1995) The Silica balance in the world ocean: a reestimate. Science 268:375–379CrossRefGoogle Scholar
  50. Triplett LD, Engstrom DR, Conley DJ, Schellhaass SM (2008) Silica fluxes and trapping in two contrasting natural impoundment of the upper Mississippi River. Biogeochemistry 87:217–230CrossRefGoogle Scholar
  51. Turner RE, Qureshi N, Rabalais NN, Dortch Q, Justic D, Shaw RF, Cope J (1998) Fluctuating silicate:nitrate ratios and coastal plankton food webs. Proc Natl Acad Sci 95:13048–13051CrossRefGoogle Scholar
  52. Vannote RL, Minshall GW, Cummins KW, Sedell JR, Cushing CE (1980) The river continuum concept. Can J Fish Aqu Sci 37:130–137CrossRefGoogle Scholar
  53. West AJ, Galy A, Bickle M (2005) Tectonic and climate controls on silicate weathering. Ear Plan Sci Lett 235:211–228CrossRefGoogle Scholar
  54. Wigand C, Thursby GB, McKinney RA, Santos AF (2004) Response of spartina patens to dissolved inorganic nutrient addition in the field. J Coast Res 45:134–149CrossRefGoogle Scholar
  55. Windham L (2001) Comparison of biomass production and decomposition between phragmites australis (common reed) and spartina patens (salt hay grass) in brackish tidal marshes of New Jersey, USA. Wetlands 21:179–188CrossRefGoogle Scholar
  56. Vieillard AM, Fulweiler RW, Hughes ZJ, Carey JC (2011) The ebb and flood of dissolved and biogenic silica fluxes from a temperate salt marsh. Estuar Coast Shelf Sci. doi:10.1060/j.ecss2011.10.012
  57. Yelerton GF, Hackney CT (1986) Flux of dissolved organic carbon and porewater through the substrate of a spartina alterniflora marsh in North Carolina. Estuar Coast Shelf Sci 22:255–267CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.Department of Earth SciencesBoston UniversityBostonUSA

Personalised recommendations