Phosphorus wind erosion

Like nitrates, phosphates are included in the indicative list of main pollutants (Water Framework Directive, 2000/60/EC) because of their contribution to eutrophication. Phosphorus is an essential nutrient for all plants and in modem agriculture this element has to be supplied to the crops as fertilizer. Wind erosion, surface mnoff and leaching constitute the main pathways for transport of phosphoms from terrestrial to aquatic ecosystems. The process is accelerated by agriculture, animal husbandry and anthropogenic discharges. 

In addition to a complete water balance, EPIC estimates plant biomass production, fertilizer use, wind and water erosion, loss of nitrogen and phosphorus from the soil, and the effect of nutrient loss from the soil on plant growth. 

Finally, it must be noted that the evolution of tolerance is a necessary condition for the evolution of a population able to colonize a mine, but it may not be sufficient. Mines differ from normal habitats in many ways apart from mere metal contamination the soil structure is usually worse, and the organic content less, so that the soils dry out quickly the soils are frequently very deficient in nitrogen and phosphorus and other essential elements and wind and water erosion may mean that seedling establishment is very difficult (Baker and Proctor, 1990). The result is that plants have to be able to adapt to all these conditions as well as to the metal contamination in practice, only those species which show at least some preadaptation to these harsh conditions are going to be able to evolve tolerant races. It may well be that it is this factor, rather than the evolution of tolerance per se, that is most important in determining which species are able to evolve tolerant races. Such arguments may be relevant when comparing the evolution of tolerance in mine environments and aerially-contaminated sites such as those around smelters, where soil conditions and selective forces are markedly different (Baker, 1987). 

---