title: Organic complexation of copper in throughfall and open field bulk deposition: Influence of the tree canopy of Mediterranean forest ecosystems.
abstract: The complexing capacity for Cu ions (LT) and the apparent stability constant values (logKapp) were measured in throughfall (TF) and open field bulk deposition (BD), at two Mediterranean forest ecosystems of western Greece. LTwas measured for the first time in the TF of natural forests. Concentrations of LTwere three-to-four-fold higher in TF (mean ± st.dev: 2014 ± 769 nM for Varetada and 1565 ± 595 nM for Karpenissi) compared to those in BD (531 ± 517 nM and 468 ± 321 nM, respectively). In all TF and BD samples, LTconcentrations were significantly higher than the corresponding total Cu concentrations, indicating that Cu was fully complexed. The LT/TOC ratios in TF were found comparable between the two study sites (235 ± 149 nM mg-1C for Varetada and 256 ± 233 nM mg-1C for Karpenissi) and with those of BD (226 ± 257 and 163 ± 163 nM mg-1C, respectively). The determined mean logKappvalues were almost identical in TF (6.8 ± 0.7 at Varetada; 6.8 ± 0.6 at Karpenissi) and BD (6.5 ± 0.6 at Varetada; 6.8 ± 0.3 at Karpenissi), pointing to the fact that regardless of the enrichment of TF in ligands (LT(TF)> LT(BD)) the type of binding sites remain the same. The logKappvalues which were obtained herewith are similar to those obtained for humic-like substances (HULIS), indicating them as the most widespread type of ligands in BD and TF.
authors.affiliation: National and Kapodistrian University of Athens, Department of Chemistry, Laboratory of Environmental Chemistry, Panepistimiopolis, 157 84, Athens, Greece. Electronic address: skarav@chem.uoa.gr.
authors.forename: Sotirios
authors.initials: S
authors.lastname: Karavoltsos
authors.affiliation: National and Kapodistrian University of Athens, Department of Chemistry, Laboratory of Environmental Chemistry, Panepistimiopolis, 157 84, Athens, Greece.
authors.forename: Fotios
authors.initials: F
authors.lastname: Fotiadis
authors.affiliation: H.A.O. DEMETER, Institute of Mediterranean Forest Ecosystems, Terma Alkmanos, 115 28 Athens, Greece.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Michopoulos
authors.affiliation: National and Kapodistrian University of Athens, Department of Chemistry, Laboratory of Environmental Chemistry, Panepistimiopolis, 157 84, Athens, Greece.
authors.forename: Aikaterini
authors.initials: A
authors.lastname: Sakellari
authors.affiliation: Ruđer Bošković Institute, Center for Marine and Environmental Research, P.O. Box 180, 10002 Zagreb, Croatia.
authors.forename: Marta
authors.initials: M
authors.lastname: Plavšić
authors.affiliation: H.A.O. DEMETER, Institute of Mediterranean Forest Ecosystems, Terma Alkmanos, 115 28 Athens, Greece.
authors.forename: Athanassios
authors.initials: A
authors.lastname: Bourletsikas
authors.affiliation: H.A.O. DEMETER, Institute of Mediterranean Forest Ecosystems, Terma Alkmanos, 115 28 Athens, Greece.
authors.forename: Kostas
authors.initials: K
authors.lastname: Kaoukis
authors.affiliation: National and Kapodistrian University of Athens, Department of Chemistry, Laboratory of Analytical Chemistry, Panepistimiopolis, 157 84, Athens, Greece.
authors.forename: Nikolaos S
authors.initials: NS
authors.lastname: Thomaidis
authors.affiliation: National and Kapodistrian University of Athens, Department of Chemistry, Laboratory of Environmental Chemistry, Panepistimiopolis, 157 84, Athens, Greece.
authors.forename: Manos
authors.initials: M
authors.lastname: Dassenakis
authors.affiliation: National and Kapodistrian University of Athens, Department of Chemistry, Laboratory of Environmental Chemistry, Panepistimiopolis, 157 84, Athens, Greece.
authors.forename: Michael
authors.initials: M
authors.lastname: Scoullos
mesh_terms: D003300:Copper / Q000032:analysis / Q000737:chemistry*; D017753:Ecosystem; D065928:Forests; D006115:Greece; D014197:Trees
chemical_list: D003300:Copper
keywords: Apparent stability constant; Bulk deposition; Canopy; Copper complexing capacity; Throughfall