Understanding the long-term dynamics of vegetation since 1953 in high-mountain regions

Alpine ecosystems, highly sensitive to climate change, are experiencing shifts in species ranges and community structure. These changes are driven by a complex interplay of climatic and environmental factors, land use changes, geomorphological dynamics, and species interactions, which can often lead to contrasted and sometimes unexpected dynamics. Historical records provide a valuable opportunity to capture these complexities by revealing long-term changes, opening a gateway to hypothesise about the key underlying processes. We investigated changes in the floristic composition of subalpine to nival vegetation communities by resurveying a period of 70 years. To understand vegetation patterns, we (i) resampled vegetation at plot level and remapped the areas, (ii) analysed the role of driving climate, environmental, and land use factors on vegetation distribution and vascular plant species richness, and (iii) modelled plant-plant interactions from community data. The results reveal that ve..., Fieldwork
The study area was located within the Stilfserjoch/Stelvio National Park (46°31'19\" N, 10°25'2\" E, Bormio, Italy) and extends from 2000 m to 3094 m above sea level (a.s.l.). Historical data from 1953 documented plant communities in the study area using 219 plots (Giacomini and Pignatti, 1955). The plots were characterised based on elevation, inclination, aspect, and geographical location within this region. These informations facilitated the selection and repositioning of 42 original plots in 2023, using the topographical parameters derived from the 2015 digital elevation model (DEM; Regione Lombardia©). For full comparison with the original data, the survey method was based on Giacomini and Pignatti (1953), using the same plot size along with the original cover scale. Vegetation surveys were performed in July 2023. Permit for the fieldwork by: \"Ente regionale per i servizi all'agricoltura e alle foreste\" (ERSAF), with the number - ERSAF.2023.0003633.
The available map of the ..., , # Understanding the long-term dynamics of vegetation since 1953 in high-mountain regions

[https://doi.org/10.5061/dryad.hdr7sqvtk ](https://doi.org/10.5061/dryad.hdr7sqvtk)

## Description of the data and file structure

Species data for 1953 were derived from Giacomini and Pignatti, 1955. The vegetation sampling was performed in July 2023.

### Files and variables

#### File: Environmental\_variables.xlsx

**Description:** 

The data set with the environmental variables include all environmental variables used. The columns with the Landolt indicator values (LIV) from Landolt et al., 2010 contain the community weighted means for each plot. Climatic variables were derived from: Downscaling of bioclimatic variables (Climate EU software, Marchi et al., 2020) for 1953 and the recent period.

##### Variables

* plot_ID, year of survey, elevation [m a.s.l.]m inclination [°], eastness, northness, log stream power index, morphology, livestock units, potential incomin solar radiation [Wh m-2],...