DOI: 10.5061/dryad.j0zpc86db
title: Data from: Land-use legacies influence tree water-use efficiency and nitrogen dynamics in recently established European forests

description: 1. Forest regrowth following farmland (agriculture and pasture)
 abandonment has been positively associated with a number of processes
 including the regulation of hydrological cycling, the enhancement of soil
 functioning, and an increase in forest productivity and carbon (C)
 sequestration. Although these changes in ecosystem functioning
 post-farmland abandonment have been observed in multiple locations and
 studies, the ecophysiological basis underpinning these patterns remains
 unclear. Here, we examine whether increased forest expansion following
 pastureland abandonment is associated with greater water-use efficiency
 (WUE) and legacies from previous land use in terms of nitrogen (N)
 availability. 2. We thus explored differences in leaf traits and
 N availability between recently established (post-1950) beech (Fagus
 sylvatica L.) forests on former pastureland and long-established beech
 forests (pre-1950). The investigated leaf traits were leaf specific area
 (SLA), leaf N concentration (%N) and intrinsic WUE (iWUE, i.e. the ratio
 between photosynthesis and stomatal conductance); as well, leaf and soil
 stable N isotope composition (δ15N) and total %N were used to assess
 changes in N availability. Finally, we compared the correlation strength
 between the above-mentioned parameters and those associated with tree
 productivity (wood density and basal area increment, BAI) and the richness
 of ectomycorrhizal fungi (ECM) in these two forest types.
 3. Recent forests had greater iWUE than long-established forests,
 which was associated more with lower SLA than leaf %N. Leaf and soil δ15N
 were more robust proxies than %N for detecting differences in N
 availability. Less negative leaf and soil δ15N values in recent vs.
 long-established forests suggest, on one hand, greater N availability,
 probably due to higher historical N input originating from animal excreta
 on these former pasturelands, and, on the other, an increase in N loss
 pathways. 4. Our results point to greater correlations between
 leaf δ15N, tree iWUE, and productivity in recent forests than in
 long-established forests, thereby suggesting a close link between C and N
 cycles. Our findings also highlight different N dynamics between the two
 forest types, with recent forests showing ‘leaky’ N cycling wherever lower
 N retention by trees and associated ECM fungi occurs as a legacy of
 previous land use.
description: For details on experimental sites, leaf and soil sampling and
 chemical and stable isotope analyses please refer to the Materials and
 Methods in the paper by Guerrieri et al. "Land-use legacies influence
 tree water-use efficiency and nitrogen dynamics in recently established
 European forests."
description: Resources shared are listed below: 1-
 "Guerrieri_et_al_metadata"- details of all the parameters
 included in the datasets; 2-
 "Guerrieri_et_al_LeafData" - dataset including site and tree
 parameters and all leaf traits; 3-
 "Guerrieri_et_al_SoilData" -  subset where both leaf traits and
 soil parameters were measured.