title: Four decades of post-agricultural forest development have caused major redistributions of soil phosphorus fractions.
abstract: Fertilisation of agricultural land causes an accumulation of nutrients in the top soil layer, among which phosphorus (P) is particularly persistent. Changing land use from farmland to forest affects soil properties, but changes in P pools have rarely been studied despite their importance to forest ecosystem development. Here, we describe the redistributions of the P pools in a four-decadal chronosequence of post-agricultural common oak (Quercus robur L.) forests in Belgium and Denmark. The aim was to assess whether forest age causes a repartitioning of P throughout the various soil P pools (labile P, slowly cycling P and occluded P); in particular, we addressed the time-related alterations in the inorganic versus organic P fractions. In less than 40 years of oak forest development, significant redistributions have occurred between different P fractions. While both the labile and the slowly cycling inorganic P fractions significantly decreased with forest age, the organic fractions significantly increased. The labile P pool (inorganic + organic), which is considered to be the pool of P most likely to contribute to plant-available P, significantly decreased with forest age (from >20 to <10% of total P), except in the 0-5 cm of topsoil, where labile P remained persistently high. The shift from inorganic to organic P and the shifts between the different inorganic P fractions are driven by biological processes and also by physicochemical changes related to forest development. It is concluded that the organic labile P fraction, which is readily mineralisable, should be taken into account when studying the bioavailable P pool in forest ecosystems.
authors: Ghent University, Melle, Belgium. An.Deschrijver@Ugent.be
authors: An
authors: A
authors: De Schrijver
authors: Lars
authors: L
authors: Vesterdal
authors: Karin
authors: K
authors: Hansen
authors: Pieter
authors: P
authors: De Frenne
authors: Laurent
authors: L
authors: Augusto
authors: David Ludovick
authors: DL
authors: Achat
authors: Jeroen
authors: J
authors: Staelens
authors: Lander
authors: L
authors: Baeten
authors: Luc
authors: L
authors: De Keersmaeker
authors: Stefaan
authors: S
authors: De Neve
authors: Kris
authors: K
authors: Verheyen
mesh_terms: D001530:Belgium; D002244:Carbon / Q000032:analysis / Q000378:metabolism; D003718:Denmark; D006863:Hydrogen-Ion Concentration; D010758:Phosphorus / Q000032:analysis* / Q000378:metabolism; D018517:Plant Roots; D029963:Quercus / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D013997:Time Factors; D014197:Trees / Q000378:metabolism
chemical_list: D012987:Soil; D010758:Phosphorus; D002244:Carbon