Phosphorus cycling in grasslands and forests of differing diversity and land use

随着植物多样性的增加，养分利用效率越来越高，导致土壤溶液中养分浓度降低。这已被证明为N，但不是其他重要的营养物质，如P.在管理的生态系统，多样性是密切相关的土地利用强度和历史。要了解土壤中养分浓度的控制，必须解开土地利用和生物多样性的影响。因此，我们建议研究土地利用和生物多样性对草地和森林系统中的P循环的影响的三个生物多样性勘探站。我们的目标是解开土地利用和植物多样性的影响1）土壤中的磷（总，无机和有机），2）土壤中的磷释放（磷矿物的溶解和有机质的矿化），和3）P在植物中的所有深入研究的子地块的每个探索（草地和森林）。此外，我们将评估土地利用的做法对土壤中的磷的影响，通过使用新的同位素技术，即在磷酸盐d18O的测定。我们将确定土壤和植物生物量中的磷库，溶解和矿化释放的磷，以及从土壤中提取的磷酸盐中的同位素特征（d18O）。

Increasingly efficient nutrient exploitation with increasing plant diversity results in lower nutrient concentrations in soil solution. This has been shown for N but not for other important nutrients such as P. In managed ecosystems, diversity is closely linked to land-use intensity and history. To understand the controls of nutrient concentrations in soil the land-use and biodiversity effects must be disentangled. Therefore, we propose to study the effect of land use and biodiversity on P cycling in grassland and forest systems of the three biodiversity exploratories. Our objective is to disentangle the effect of land use and plant diversity on 1) P in soil (total, inorganic, and organic), 2) P release in soil (dissolution of P minerals and mineralization of organic matter), and 3) P in plants in all intensively studied subplots of each exploratory (grasslands and forests). Furthermore, we will assess the influence of land-use practices on P in soil by using novel isotope techniques, i.e. the determination of d18O in phosphates. We will determine P pools in soil and plant biomass, P release by dissolution and mineralization, and the isotopic signature (d18O) in phosphate extracted from soil.