Water Pollution -Plant nutrients
Water Pollution-Plant Nutrients
Plant nutrients Plant growth requires various nutrients Major nutrient elements: CI N, P. trace elements: S, Si, Cl, I, and metallic elements(Fe, Mn, Cu, etc) The minor elements because of the low demand can usually be supplied at adequate rates in natural waters The required proportion of the major nutrient elements isC∴N:P=106:16:1 C despite the largest demand is plentifully supplied to phytoplanktons from CO2 in the atmosphere
Plant nutrients • Plant growth requires various nutrients. – Major nutrient elements: C, N, P. – trace elements: S, Si, Cl, I, and metallic elements (Fe, Mn, Cu, etc). • The minor elements, because of the low demand, can usually be supplied at adequate rates in natural waters. • The required proportion of the major nutrient elements is C:N:P=106:16:1. • C, despite the largest demand, is plentifully supplied to phytoplanktons from CO2 in the atmosphere
Natural nutrient cycling in aquatic ecosystem N,atmosphere) (soll; detergents; sewage nitrates(soil; sewage) COz(atmosphere) (usually limited) (possibly limited (usually plentiful) (Sufficient O2) Trace elements CO 〔Fe,Mn,Cu,etc.) Primary Prod FEE algae and other nitrogen fixing and photosynthetic organisms assimilate Bacterial Decomposition C N, Pin the atomic ratios of 106: 16: 1 of plant and animal debris Growth of fish ad ouer secondary producers (Sufficient O,) ag吗g Sedimentation of plant and animal debris
Natural nutrient cycling in aquatic ecosystem
N and p are often the limiting nutrients The limiting nutrient is the least available element in relation to its required abundance N is abundant in the form of N2, but N2 can only be utilized througl gh N2-fixing bacteria In waters where N2-fixing algal species are common, N is not usually limiting In regions where N2-fixing species are less abundant especially the oceans, N maybe the limiting nutrient This leaves P as the limiting element to plant growth This shortage keeps the spread of vegetation under control
N and P are often the limiting nutrients • The limiting nutrient is the least available element in relation to its required abundance. • N is abundant in the form of N2, but N2 can only be utilized through N2-fixing bacteria. • In waters where N2-fixing algal species are common, N is not usually limiting. – In regions where N2-fixing species are less abundant, especially the oceans, N maybe the limiting nutrient. • This leaves P as the limiting element to plant growth. • This shortage keeps the spread of vegetation under control
Phytoplankton productivity as a function of N and p concentrations and sunlight In winter low temperature and Phosphates and Phytoplankton sunlight are the nitrates at surface productivity limiting factors to talal phytoplankton productivity. In summer, nutriel become the limiting factor Decay of dead plant matter replenish nutrients leading to a secondary peak of phytoplankton winter Spring Summer Autumn winter productivity
Phytoplankton productivity as a function of N and P concentrations and sunlight In winter, low temperature and sunlight are the limiting factors to phytoplankton productivity. In summer, nutrients become the limiting factor. Decay of dead plant matter replenish nutrients, leading to a secondary peak of phytoplankton productivity