caa a22 4500 477110584 CHVBK 20180405111607.0 cr unu---uuuuu 170330e19960101xx s 000 0 eng 10.1007/BF00011596 doi (NATIONALLICENCE)springer-10.1007/BF00011596 Canopy throughfall of Picea abies (L.) Karst. as depending on trace gas concentrations [Elektronische Daten] [Stefan Slovik, Árpad Balázs, Alfred Siegmund] At six sites in central Germany consequences of SO2, NOX and O3 deposition and of acid precipitation on canopy throughfall of sulphate, nitrate, ammonium, organic acids and of metal cations from Norway spruce crowns were investigated in the field. Measured canopy throughfall rates (mmol ion kg-1 needle dw a-1 are separated in (i) "background” ion throughfall rates in clean air and (ii) trace gas-(or acid interception)-dependent throughfall rates at ambient trace gas concentrations. Based on synchronously measured pollution, precipitation and canopy throughfall data, statistical response functions are given, which allow the separate estimation of annual rates of sulphur and nitrogen deposition into spruce canopies if only annual means of SO2 or NO2 concentrations in air are known. The specific SO2 deposition rate of (0.841±0.214) mmol S kg-1 needle dw a-1 (nPa SO2 Pa-1)-1 is 2.3 times higher than the specific stomatal SO2 uptake. The NO2-dependent nitrogen deposition of (2.464±0.707) mmol N kg-1 needle dw a-1 (nPa NO2 Pa-1)-1 is 2.2 times higher than the specific stomatal NOX (NO2+NO) uptake. These ratios (2.3≈2.2) are explained by the percentage of annual hours with open needle stomata. The shape of observed "epicuticular” SO2 and NOX deposition curves and of stomatal SO2 and NOX uptake curves are congruent. As for stomatal NOX uptake, there is an apparent compensation point at (5 to 8) nPa NO2 Pa-1. There is significant SO2-dependent canopy throughfall of Ca>K>Al>Mg>Fe in this order of relative importance. NOX deposition in spruce canopies reduces K+ throughfall and it weakly promotes throughfall of Mn2+ and Zn2+. There was no significant codeposition of sulphate and ammonium and no ion exchange of intercepted H3O+ with nutrient cations at the measured ambient pH values of the precipitation water. In the presence of O3, throughfall of Mn2+ is reduced and throughfall of K+, Ca2+ and Al3+ is enhanced. In the cooperative presence of SO2, NO2 and O3 pollution in the field there is a 1.3-fold increase of the annual K+ demand and a 1.5-fold Mg2+ demand of spruce canopies relative to the situation in clean air. This trace gas-dependent additional cation demand of spruce canopies corresponds to a needle loss percentage of (23 to 33)% if the additional K+ and Mg2+ throughfall could not be recycled in spruce ecosystems. Observed canopy thinning ranges from (13 to 26)% at the investigated six spruce stands. Kluwer Academic Publishers, 1996 acid load (proton balance) nationallicence air pollution (SO2, NO2, NO, O3) nationallicence canopy leaching (SO42-, NO3-, NH4+, Ca2+, Mg2+, K+, Mn2+) nationallicence dry and wet deposition (canopy throughfall, stomata) nationallicence epicuticular trace gas absorption nationallicence forest decline nationallicence Norway spruce ( Picea abies , Pinaceae) nationallicence Aspec : Specific needle surface area per kg needle dry matter (m2kg-1 needle dw) nationallicence Atot : Total needle surface of spruce stands (ha ha-1) nationallicence [gas]a : Ambient trace gas concentration (gas=SO2 nationallicence NO2 or O3) in air (nPa Pa-1=ppb) nationallicence GP : Number of days per annual growth period d a-1) nationallicence ICH30+ : Acid interception rate (Eq H3O+ kg-1 needle dw a-1) nationallicence ko : Trace gas-independent ion throughfall rate constant (mmol kg-1 needle dw a-1) nationallicence kgas : SO2-,NO2-or O3-dependent ion throughfall rate per unit of trace gas pollution (mmol kg-1 needle dw a-1 (nPa Pa-1)-1) nationallicence kH30 : Specific H3O+/Me+ exchange ratio (mol mol-1) nationallicence Lo : Background throughfall rate at [gas]a=0 (mmol kg-1 needle dw a-1) nationallicence Lion : Canopy throughfall rate of ions (mmol kg-1 needle dw a-1) nationallicence L'ion : Trace gas dependent ion throughfall (mEq kg-1 needle dw a-1 (nPa Pa-1)-1) nationallicence LAI : Leaf area index of the canopy (m2 projected needle surface m-2 ground) nationallicence Me+ : Equivalents of metal cations (Eq) nationallicence N : Stock of needles of spuce stands in the field (kg needle dw ha-1) nationallicence P% : Percentage of needle loss relative to a healthy reference (%) nationallicence r : Pearson correlation coefficient (no dimension) nationallicence R : COO--Sum of all organic anion equivalents≈Σ Cat+ nationallicence Σ An- : (Eq kg-1 needle dw a-1) nationallicence Σ An- : Sum of all measured inorganic anion equivalents (Eq kg-1 needle dw a-1) nationallicence Σ Cat+ : Sum of all measured inorganic cation equivalents (Eq kg-1 needle dw a-1) nationallicence Slovik Stefan Julius-von-Sachs-Institut für Biowissenschaften mit Botanischtem Garten der Universität Würzburg, Lehrstuhl für Botanik I, Mittlerer Dallenbergweg 64, 97082, Würzburg, Germany aut Balázs Árpad Hessische Forstliche Versuchsanstalt, Abteilung Forsthydrologie, Prof.-Oelkers-Str. 6, 34346, Hannoversch Münden., Germany aut Siegmund Alfred Hessische Landesanstalt für Umwelt, Rheingaustraße 186, 65203, Wiesbaden, Germany aut Plant and Soil Kluwer Academic Publishers; gopher://gopher.wkap.nl 178/2(1996-01-01), 295-310 0032-079X 178:2<295 1996 178 11104 https://doi.org/10.1007/BF00011596 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00011596 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Slovik Stefan Julius-von-Sachs-Institut für Biowissenschaften mit Botanischtem Garten der Universität Würzburg, Lehrstuhl für Botanik I, Mittlerer Dallenbergweg 64, 97082, Würzburg, Germany aut NATIONALLICENCE 700 1- Balázs Árpad Hessische Forstliche Versuchsanstalt, Abteilung Forsthydrologie, Prof.-Oelkers-Str. 6, 34346, Hannoversch Münden., Germany aut NATIONALLICENCE 700 1- Siegmund Alfred Hessische Landesanstalt für Umwelt, Rheingaustraße 186, 65203, Wiesbaden, Germany aut NATIONALLICENCE 773 0- Plant and Soil Kluwer Academic Publishers; gopher://gopher.wkap.nl// 178/2(1996-01-01), 295-310 0032-079X 178:2<295 1996 178 11104 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer