Protected Areas and Extensive Productions Systems: A Phosphorus Challenge beyond Human Food/Response from Childers: Phosphorous Challenges beyond the Food System

Childers and colleagues (2011) point out the vitality of phosphorus (P) to life, the large amounts trapped in biomass, the widespread limitation of growth and production in marine, freshwater, and terrestrial ecosystems due to its cycling characteristics, and the current anthropogenic dependence on nonrenewable sources of concentrated P. The article aimed to provide sustainable solutions for humanity by suggesting ways to improve cycling rather than losing P and provided a good overview of the problem focusing on food production. The ultimate result may well be P depletion in many of these nonagricultural ecosystems, resulting in lower yields of the products that humans harvest, but I am not aware of many situations where mineral P as fertilizer is being used to replace this extracted P. As such, these aspects of the greater human P cycle do not fit neatly into the aspects of the P cycle we reviewed, which begins with the mining of mineral P to support human food production.