data_sheet_Gentilesca_et_al.txt (557.32 kB)
Data from: Nitrogen deposition outweighs climatic variability in driving annual growth rate of canopy beech trees: evidence from long-term growth reconstruction across a geographic gradient
dataset
posted on 2018-03-14, 16:13 authored by Tiziana Gentilesca, Angelo RitaAngelo Rita, Michele Brunetti, Francesco Giammarchi, Stefano Leonardi, Federico Magnani, Twan van Noije, Giustino Tonon, Marco BorghettiMarco BorghettiIn this study, we investigated the role of
climatic variability and atmospheric nitrogen deposition in driving long-term tree
growth in canopy beech trees along a geographic gradient in the montane belt of
the Italian peninsula, from the Alps to the southern Apennines. We sampled dominant
trees at different developmental stages (from young to mature tree cohorts, with
tree ages spanning from 35 to 160 years) and used stem analysis to infer historic
reconstruction of tree volume and dominant height. Annual growth volume (GV) and height (GH) variability were related
to annual variability in model simulated atmospheric nitrogen deposition and site-specific
climatic variables, (i.e. mean
annual temperature, total annual precipitation, mean growing period temperature,
total growing period precipitation, and standard precipitation evapotranspiration
index) and atmospheric CO2 concentration, including tree cambial age among growth predictors. Generalized additive
models (GAM), linear mixed-effects
models (LMM), and Bayesian regression
models (BRM) were independently employed
to assess explanatory variables. The main results from our study were as
follows: i) tree age was the main explanatory variable for
long-term growth variability; ii) GAM, LMM,
and BRM results consistently indicated climatic variables and CO2 effects
on GV and GH
were weak, therefore evidence of recent climatic variability influence on beech
annual growth rates was limited in the montane belt of the Italian peninsula; iii)
instead, significant positive nitrogen deposition (Ndep) effects were repeatedly observed in GV
and GH; the positive effects of Ndep on canopy height growth rates, which tended to
level off at Ndep values
greater than approximately 1.0 g m-2 y-1 were interpreted
as positive impacts on forest stand above-ground net productivity at the
selected study sites