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][2001][2002][2003][2004][2005][2006][2007][2008][2009]

Variables related to nitrogen deposition improve defoliation models for European forests

“…However, in some of the plots used in this study, throughfall deposition of N compounds (mainly ammonium) was lower than open field deposition because of the active uptake by the foliage (e.g. Ferretti et al 2014b). Thus, we decided to use N thr deposition of total N as a predictor because it represents the total amount of N carried to the forest soil through atmospheric deposition and canopy processes.…”

“…Therefore, we did not consider time trends and were not concerned with time dependency. Within such a context, a stepwise procedure was adopted (Ferretti et al 2014b): First, a reference model was considered, with geographical (latitude, longitude, elevation), stand (tree density) and meteorological variables (annual precipitation and per cent of precipitation occurring in summer) as predictors of F 25 (dependent variable). Secondly, individual sets of predictors were added stepwise to the reference model to evaluate their additional role in explaining F 25 (Table 1).…”

“…biotic factors such as pests, or abiotic factors such as storms) (hereafter referred as BADoAP), annual total N thr deposition and a set of variables known to be directly or indirectly related to N deposition, namely foliar N ratios (N/Ca, N/P, N/K, N/Mg) and soil pH, exchangeable base cations (BCE) and C/N ratio in the mineral top soil (Ferretti et al 2014b;Cools and De Vos 2011;Cools et al 2014) (Table 1). For both predictors and response variables, assessment and measurement methods were those reported by Ferretti and Fischer (2013).…”

Critical loads and nitrogen availability under deposition and harvest scenarios for conifer forests in Ireland

“…The deposition of reactive N can have a number of important ecological effects on terrestrial ecosystems including changes to plant communities (Fenn et al, 2003;Bobbink et al, 2010); tree nutrition (Crowley et al, 2012;Ferretti et al, 2014;Jonard et al, 2015); growth and carbon sequestration (de Vries et al, 2006;Thomas et al, 2010;Ferretti et al, 2014) and decomposition (Janssens et al, 2010). Forests generally retain the majority of N deposition; however, in areas with continued high (N10 kg N ha − 1 year − 1 ) deposition the occurrence of nitrate (NO 3 − ) leaching suggests that the retention capacity of these ecosystems has been exceeded-or saturated (Aber et al, 2003;Gundersen et al, 2006;van der Salm et al, 2007;Dise et al, 2009).…”

Adaptive silviculture to face up to the new challenges: the ManForCBD experience

“…Florence,November 26 th -29 th 2014 An additional, emerging benchmark to forest management is the progress of environmental conditions' shift. This involves directly both physics and chemistry of growth medium -atmosphere and soil -with concurrent and counteracting factors (increase of air temperature and CO 2 content, abrupt changes in rainfall regime, extreme events, airborne acidifying pollution, N fertilization, ozone level) (Ferretti et al, 2014;Nabuurs et al, 2013;Seidl et al, 2014). Because of the full involvement of growth medium attributes, tree growth level and pattern (i) provide the evidence of this occurrence and (ii) synthesize the balance between positive and negative inputs in the short, as well as in the long run (Solberg et al, 2009).…”