| Title | On the tracks of Nitrogen deposition effects on temperate forests at their southern European range - an observational study from Italy |
| Abstract | We studied forest monitoring data collected at permanent plots in Italy over the period 2000-2009 to identify the possible impact of nitrogen (N) deposition on soil chemistry, tree nutrition and growth. Average N throughfall (N-NO3+N-NH4) ranged between 4 and 29kg ha(-1)yr(-1), with Critical Loads (CLs) for nutrient N exceeded at several sites. Evidence is consistent in pointing out effects of N deposition on soil and tree nutrition: topsoil exchangeable base cations (BCE) and pH decreased with increasing N deposition, and foliar nutrient N ratios (especially N:P and N:K) increased. Comparison between bulk openfield and throughfall data suggested possible canopy uptake of N-,N- levelling out for bulk deposition >4-6kgha(-1)yr(-1). Partial Least Square (PLS) regression revealed that - although stand and meteorological variables explained the largest portion of variance in relative basal area increment (BAI(rel) 2000-2009) - N-related predictors (topsoil BCE, C:N, pH; foliar N-ratios; N deposition) nearly always improved the BAI(rel) model in terms of variance explained (from 78.2 to 93.5%) and error (from 2.98 to 1.50%). N deposition was the strongest predictor even when stand, management and atmosphere-related variables (meteorology and tropospheric ozone) were accounted for. The maximal annual response of BAI(rel) was estimated at 0.074-0.085% for every additional kgN. This corresponds to an annual maximal relative increase of 0.13-0.14% of carbon sequestered in the above-ground woody biomass for every additional kgN, i.e. a median value of 159 kgC per kgN ha(-1)yr(-1) (range: 50-504 kgC per kgN, depending on the site). Positive growth response occurred also at sites where signals of possible, perhaps recent N saturation were detected. This may suggest a time lag for detrimental N effects, but also that, under continuous high N input, the reported positive growth response may be not sustainable in the long-term. |
| Source | Global change biology (Print) 20 (11), pp. 3423–3438 |
| Keywords | CONECOFOR forest monitoringgrowth and carbon sequestrationN critical loadsPLS regressionsoil and foliar nutrients |
| Journal | Global change biology (Print) |
| Editor | Blackwell Science., Oxford, Regno Unito |
| Year | 2014 |
| Type | Articolo in rivista |
| DOI | 10.1111/gcb.12552 |
| Authors | Ferretti, Marco; Marchetto, Aldo; Arisci, Silvia; Bussotti, Filippo; Calderisi, Marco; Carnicelli, Stefano; Cecchini, Guia; Fabbio, Gianfranco; Bertini, Giada; Matteucci, Giorgio; De Cinti, Bruno; Salvati, Luca; Pompei, Enrico |
| Text | 299898 2014 10.1111/gcb.12552 ISI Web of Science WOS 000343762800012 CONECOFOR forest monitoring growth and carbon sequestration N critical loads PLS regression soil and foliar nutrients On the tracks of Nitrogen deposition effects on temperate forests at their southern European range an observational study from Italy Ferretti, Marco; Marchetto, Aldo; Arisci, Silvia; Bussotti, Filippo; Calderisi, Marco; Carnicelli, Stefano; Cecchini, Guia; Fabbio, Gianfranco; Bertini, Giada; Matteucci, Giorgio; De Cinti, Bruno; Salvati, Luca; Pompei, Enrico TerraData Environmetr; University of Florence; CNR Ist Studio Ecosistemi; University of Florence; CRA Ctr Ric Selvicoltura; CNR Ist Biol Agroambientale Forestale; CNR Ist Sistemi Agr Forestali Mediterraneo; CRA Ctr Ric Studio Relaz Pianta Suolo; CFS Div 6 We studied forest monitoring data collected at permanent plots in Italy over the period 2000 2009 to identify the possible impact of nitrogen N deposition on soil chemistry, tree nutrition and growth. Average N throughfall N NO3 N NH4 ranged between 4 and 29kg ha 1 yr 1 , with Critical Loads CLs for nutrient N exceeded at several sites. Evidence is consistent in pointing out effects of N deposition on soil and tree nutrition topsoil exchangeable base cations BCE and pH decreased with increasing N deposition, and foliar nutrient N ratios especially N P and N K increased. Comparison between bulk openfield and throughfall data suggested possible canopy uptake of N ,N levelling out for bulk deposition >4 6kgha 1 yr 1 . Partial Least Square PLS regression revealed that although stand and meteorological variables explained the largest portion of variance in relative basal area increment BAI rel 2000 2009 N related predictors topsoil BCE, C N, pH; foliar N ratios; N deposition nearly always improved the BAI rel model in terms of variance explained from 78.2 to 93.5% and error from 2.98 to 1.50% . N deposition was the strongest predictor even when stand, management and atmosphere related variables meteorology and tropospheric ozone were accounted for. The maximal annual response of BAI rel was estimated at 0.074 0.085% for every additional kgN. This corresponds to an annual maximal relative increase of 0.13 0.14% of carbon sequestered in the above ground woody biomass for every additional kgN, i.e. a median value of 159 kgC per kgN ha 1 yr 1 range 50 504 kgC per kgN, depending on the site . Positive growth response occurred also at sites where signals of possible, perhaps recent N saturation were detected. This may suggest a time lag for detrimental N effects, but also that, under continuous high N input, the reported positive growth response may be not sustainable in the long term. 20 GCB_2014_Ferretti_Nitrogen GCB_2014_Ferretti_Nitrogen.pdf Articolo in rivista Blackwell Science. 1354 1013 Global change biology Print Global change biology Print Glob. chang. biol. Print ARISCI SILVIA aldo.marchetto MARCHETTO ALDO giorgio.matteucci MATTEUCCI GIORGIO bruno.decinti DE CINTI BRUNO TA.P02.014.002 Impatto dei cambiamenti globali sugli ecosistemi acquatici TA.P02.017.005 Sistemi forestali ed arborei Ecologia, idrologia, interazioni con l atmosfera, risposta ai fattori ambientali e di disturbo |
