Báo cáo lâm nghiệp: Response of shoot growth and gas exchange of Picea abies clones to rain acidity and the addition of ions

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Response of shoot growth and gas exchange of Picea abies clones to rain acidity and the addition of ions...
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Báo cáo lâm nghiệp: "Response of shoot growth and gas exchange of Picea abies clones to rain acidity and the addition of ions"Response of shoot growth and gas exchangeof Picea abies clones to rain acidityand the addition of ionsP. Van Elsacker I. ImpensDepartment of Biology, University of Antwerp (UIA), Universiteitsplein 1, B-26 10 Wifrijk-Antwerpen,BelgiumIntroduction without (-) and with (+) the ionic mixture men- tioned below; pH 4.0- and 4.0+: same as pH 5.6 but the solution was acidified to pH 4.0 with a (S02-/NO- mixture of sulfuric and nitric acidsThe novel forest decline observed in Eu- m mg/1 weight ratio 2.4). Ionic concentrations = 2 S04rope and the U.S.A. may be caused by were: 4.50 2.00 NOg, 1.20 NH4,several factors, among them, air pollution K+, 0.60 Ca +, 2 0.99 Na+, 1.45 CI-, 0.30is thought to be very important. Interfer- 0.30 Mg and 0.40 HS0 (Van Elsacker era/., + 2 3ence of pollutants with the ecophysiologi- 1988).cal performance of forest trees needs to Gas measured fully grown exchange was on current year shoots during the summer. C0 2be investigated in order to understand the exchange rate (CER) was measured at PPFDactual working mechanisms. The aim of saturation with a portable, closed-loop systemthis study was to examine the effect of aci- (Van Elsacker and Impens, 1986). The numberdic wet deposition on C0 exchange, 2 of data was 12 measurements x 4 treatments xneedle conductance and shoot growth of 4 (parts of) days. Needle conductance (Gn) was measured with an automatic diffusion porome-Norway spruce, particularly the effect of ter developed at the laboratory (procedure com-acidity and the addition of a realistic ionic parable to Delta-T porometer). Data were calcu-mixture to simulated acidic precipitation. lated on a needle dry weight basis (gdw- The ). 1 number of Gn data was 13 measurements x 4 treatments x 3 (parts of) days for clone 1011, and 11 x 4 x 4, respectively, for the other clones. To analyze the gas exchange data, a 3-Materials and Methods way analysis of variance with the factors pH, ions (- or +) and day was used; the factor ’day’ allowed for temporal, environmental and eco-Four year old potted plants of 3 Belgian Picea physiological variations.abies (L.) Karst. clones were grown in a green-house (clone number 1007, 1011 and 1019). The length of top and lateral current yearThe plants were sprayed 3 times a week shoots of 13 plants per treatment and per clonethroughout the growing season with a hand was measured every 3-4 d from bud break (mid-pumped sprayer. The 4 treatments were: May) until growth had stopped (July, ...