Century-scale nitrogen and phosphorus controls of the carbon cycle

Human-induced nitrogen–phosphorus imbalances alter natural and managed ecosystems across the globe

“…Potential reserves (now not profitable under current prices, but exploitable in the future with better technology and higher market prices for phosphorus). 'Land use' includes an estimation of all human activities (changes in land use, crop management and deforestation) that increase phosphorus mobilization from humus to stream water (initial mobilization less the part that is accumulated again on land) where thereafter this phosphorus mobilized can be loaded in continental waters or taken up by plants 70 .…”

Global phosphorus retention by river damming

“…The global retention of P by dams, however, remains poorly constrained (20,21). Previous estimations have simply applied a correction factor to river P loads to represent retention by dams (22)(23)(24). This approach does not distinguish between the various chemical forms of P, nor does it account for differences in reservoir hydraulics or provide information about uncertainties on retention estimates.…”

Geochemistry of phosphorus in sediment cores from Sishili Bay, China

“…On geologic timescales, P is a limiting nutrient in oceanic biogeochemical cycles (Broecker, 1982;Smith, 1984;Tyrell, 1999). In recent decades, anthropogenic activities through the form of either gaseous, liquid or solid emissions have become the cause of many of environmental issues and are responsible for major global reorganizations of the biogeochemical cycles (Mackenzie et al, 2002). It was reported that by 2000, the total overall effect of land use activities on nutrients remobilization increased to 100 Mtons nitrogen (N) and 50 Mtons P per year, with an average annual growth rate of the perturbation of 2% between 1950 and 2000 (Mackenzie et al, 2002).…”

“…In recent decades, anthropogenic activities through the form of either gaseous, liquid or solid emissions have become the cause of many of environmental issues and are responsible for major global reorganizations of the biogeochemical cycles (Mackenzie et al, 2002). It was reported that by 2000, the total overall effect of land use activities on nutrients remobilization increased to 100 Mtons nitrogen (N) and 50 Mtons P per year, with an average annual growth rate of the perturbation of 2% between 1950 and 2000 (Mackenzie et al, 2002). Besides, world fertilizer consumption puts another millions of tons of N and P each year to environment mainly in the forms of nitrate and phosphate (Mackenzie et al, 2002;Paytan and McLaughlin, 2007).…”

“…It was reported that by 2000, the total overall effect of land use activities on nutrients remobilization increased to 100 Mtons nitrogen (N) and 50 Mtons P per year, with an average annual growth rate of the perturbation of 2% between 1950 and 2000 (Mackenzie et al, 2002). Besides, world fertilizer consumption puts another millions of tons of N and P each year to environment mainly in the forms of nitrate and phosphate (Mackenzie et al, 2002;Paytan and McLaughlin, 2007). Consequently, environment becomes enriched with biological available nutrients, and a significant part of which are transferred from land to coastal margin through soil erosion, mineral dissolution, surface water runoff and so on, making eutrophication become a common phenomenon in coastal water.…”