title: Experimental evidence of large changes in terrestrial chlorine cycling following altered tree species composition.
abstract: Organochlorine molecules (Clorg) are surprisingly abundant in soils and frequently exceed chloride (Cl(-)) levels. Despite the widespread abundance of Clorg and the common ability of microorganisms to produce Clorg, we lack fundamental knowledge about how overall chlorine cycling is regulated in forested ecosystems. Here we present data from a long-term reforestation experiment where native forest was cleared and replaced with five different tree species. Our results show that the abundance and residence times of Cl(-) and Clorg after 30 years were highly dependent on which tree species were planted on the nearby plots. Average Cl(-) and Clorg content in soil humus were higher, at experimental plots with coniferous trees than in those with deciduous trees. Plots with Norway spruce had the highest net accumulation of Cl(-) and Clorg over the experiment period, and showed a 10 and 4 times higher Cl(-) and Clorg storage (kg ha(-1)) in the biomass, respectively, and 7 and 9 times higher storage of Cl(-) and Clorg in the soil humus layer, compared to plots with oak. The results can explain why local soil chlorine levels are frequently independent of atmospheric deposition, and provide opportunities for improved modeling of chlorine distribution and cycling in terrestrial ecosystems.
authors: †Department of Thematic Studies-Environmental Change, Linköping University, SE-581 83, Linköping, Sweden.
authors: Malin
authors: M
authors: Montelius
authors: ‡Andra, Research and Development Division, Parc de la Croix Blanche, 1/7 rue Jean Monnet, 92298 Châtenay-Malabry Cedex, France.
authors: Yves
authors: Y
authors: Thiry
authors: §EDF, Laboratoire National d'Hydraulique et Environnement, 78401 Chatou, France.
authors: Laura
authors: L
authors: Marang
authors: ∥Biogéochimie des écosystèmes forestiers, INRA Centre de Nancy, 54280 Champenoux, France.
authors: Jacques
authors: J
authors: Ranger
authors: ⊥Soil Science Lab, Earth and Life Institute - Environmental Sciences, Université Catholique de Louvain, Croix du Sud 2/10, 1348 Louvain-la-Neuve, Belgium.
authors: Jean-Thomas
authors: JT
authors: Cornelis
authors: †Department of Thematic Studies-Environmental Change, Linköping University, SE-581 83, Linköping, Sweden.
authors: Teresia
authors: T
authors: Svensson
authors: †Department of Thematic Studies-Environmental Change, Linköping University, SE-581 83, Linköping, Sweden.
authors: David
authors: D
authors: Bastviken
mesh_terms: D018533:Biomass; D002713:Chlorine / Q000032:analysis* / Q000493:pharmacokinetics; D017753:Ecosystem; D065928:Forests; D005602:France; D028222:Picea; D012987:Soil / Q000737:chemistry*; D013045:Species Specificity; D014197:Trees
chemical_list: D012987:Soil; D002713:Chlorine