Forest nitrogen dynamics in response to increasing nitrogen deposition: comparing above-canopy and soil fertilizations in a mature beech forest

Nitrogen (N) fertilization experiments provide critical insights into how increasing N deposition alters the balance between N retention and saturation in forest ecosystems. However, most studies have considered soil N applications, overlooking tree canopy-atmosphere interactions, leading to an incomplete understanding of the fate of N in forests. We investigated ecosystem N dynamics four years after the establishment of a nitrogen manipulation experiment in a beech forest, involving Control (N0), 30 kg N ha^-1^ y^-1^, distributed to soil (N30) and above tree canopies (N30A), and 60 kg N ha^-1^ y^-1^ applied to the soil (N60). We assessed N concentration and δ15N across forest compartments (leaves, fine roots, ectomycorrhizal root tips, soil, and litter) and quantified microbial functional genes related to soil N processes. N concentrations were minimally affected by treatments, whereas δ15N increased along compartments, particularly in the N60, indicating enhanced soil N losses. Both N..., , # Data from: Forest nitrogen dynamics in response to increasing nitrogen deposition: comparing above-canopy and soil fertilizations in a mature beech forest

Dataset DOI: [10.5061/dryad.3r2280gw1](https://doi.org/10.5061/dryad.3r2280gw1)

## Description of the data and file structure

This dataset contains measurements related to an experimental study simulating an increase in nitrogen deposition in forest ecosystems via nitrogen fertilization. It includes information on different nitrogen treatments, forest compartments considered, and measurements carried out.

* Nitrogen treatments were applied either through **above-canopy** or **soil fertilizations**, depending on the applied dose.
* Each treatment was replicated in **three plots**.
* Sampling included different forest compartments to assess responses in ecosystem nitrogen dynamics. Replicates were n=3 for all forest compartments, except for leaf litter and seeds (see Materials and Methods in Teglia et al. 2025 for more details).

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