| Title | Atmospheric deposition and canopy exchange processes in alpine forest ecosystems (northern Italy) |
| Abstract | Throughfall and bulk precipitation chemistry were studied for five years (June 1994-May 1999) at two high elevation forest sites (Val Gerola and Val Masino) which were known to differ in terms of tree health, as assessed by live crown condition. The ion concentration of bulk precipitation samples did not differ significantly between sites, except for Mg2+, while the throughfall concentrations differed in the measured values of H+, N-NO3-, Cl-, Na+, K+, DOC and weak organic acids. The results of the application of the canopy exchange model indicated a higher contribution from the dry deposition of N-NO3-, N-NH4+ and H+ at Val Gerola, where the damage symptoms were more evident. In addition, the canopy leaching of Ca2+, K+ and weak organic acids were 47, 21 and 27 % higher at Val Gerola than at Val Masino. Annual SO42- deposition fluxes (21.3 kg ha-1 yr-1 at Val Masino and 23.6 kg ha-1 yr-1 at Val Gerola) were similar to those reported for moderately polluted European and U.S. sites. Annual N loads were 13.6 and 13.1 kg ha-1 yr-1 in the bulk input, and 15.0 and 18.0 kg ha-1 yr-1 in throughfall inputs, at Val Masino and Val Gerola respectively. The contribution of the organic fraction to the total N atmospheric deposition load is significant, constituting 17% of the bulk flux and 40% of the throughfall flux. Measured nitrogen loads exceed the critical nutrient loads by several kg N ha-1 at both stations. In particular the nitrogen throughfall load at Val Gerola was about 3 times higher than the critical values |
| Source | Atmospheric environment (1994) 35/36, pp. 6421–6433 |
| Keywords | Throughfalldry depositionleachingcanopy exchange modelcritical loads |
| Journal | Atmospheric environment (1994) |
| Editor | Pergamon., Oxford, Regno Unito |
| Year | 2001 |
| Type | Articolo in rivista |
| Authors | BALESTRINI R.(1), TAGLIAFERRI A. (2) |
| Text | 42059 2001 Throughfall dry deposition leaching canopy exchange model critical loads Atmospheric deposition and canopy exchange processes in alpine forest ecosystems northern Italy BALESTRINI R. 1 , TAGLIAFERRI A. 2 1 CNR Istituto di Ricerca sulle Acque; 2 ERSAF Ente Regionale per lo Sviluppo Agricolo e Forestale Throughfall and bulk precipitation chemistry were studied for five years June 1994 May 1999 at two high elevation forest sites Val Gerola and Val Masino which were known to differ in terms of tree health, as assessed by live crown condition. The ion concentration of bulk precipitation samples did not differ significantly between sites, except for Mg2 , while the throughfall concentrations differed in the measured values of H , N NO3 , Cl , Na , K , DOC and weak organic acids. The results of the application of the canopy exchange model indicated a higher contribution from the dry deposition of N NO3 , N NH4 and H at Val Gerola, where the damage symptoms were more evident. In addition, the canopy leaching of Ca2 , K and weak organic acids were 47, 21 and 27 % higher at Val Gerola than at Val Masino. Annual SO42 deposition fluxes 21.3 kg ha 1 yr 1 at Val Masino and 23.6 kg ha 1 yr 1 at Val Gerola were similar to those reported for moderately polluted European and U.S. sites. Annual N loads were 13.6 and 13.1 kg ha 1 yr 1 in the bulk input, and 15.0 and 18.0 kg ha 1 yr 1 in throughfall inputs, at Val Masino and Val Gerola respectively. The contribution of the organic fraction to the total N atmospheric deposition load is significant, constituting 17% of the bulk flux and 40% of the throughfall flux. Measured nitrogen loads exceed the critical nutrient loads by several kg N ha 1 at both stations. In particular the nitrogen throughfall load at Val Gerola was about 3 times higher than the critical values 35/36 Lindagine si inserisce in un progetto finanziato dalla Comunita Europea ECAFO Reg. CEE 2157/92 volto allo studio delle interazioni tra inquinamento atmosferico ed ecosistemi forestali attraverso un approccio multidisciplinare che prevedeva indagini fitosanitarie, pedologiche, vegetazionali, meteorologiche, di chimica dellaria, etc. Il piano sperimentale utilizzato per studiare le deposizioni atmosferiche che prevedeva lanalisi chimica comparata delle deposizioni raccolte allinterno di un bosco sottochioma e in unarea adiacente priva di alberi campo aperto , costituisce un esempio di ricerca poco diffuso in Italia ed e risultato molto utile ai fini di conoscere 1 il ruolo della deposizione secca in aree complesse come quelle forestali e montane, 2 lentita dei flussi di deposizione totale di azoto e zolfo 3 aspetti legati alla fisiologia vegetale come il leaching foliare e lo stato nutrizionale Articolo in rivista Pergamon. 1352 2310 Atmospheric environment 1994 Atmospheric environment 1994 Atmos. environ. 1994 raffaella.balestrini BALESTRINI RAFFAELLA |
