DOI: 10.5061/dryad.crjdfn3cc
title: Data from: Fire-driven alternative vegetation states across the temperate Andes

description: The theory of alternative stable states as applied to terrestrial
 ecosystems, suggests that, under common environmental conditions,
 different vegetation types may remain stable by contrasting feedback
 processes. In the temperate Andes, forests and shrublands of Nothofagus
 species have been proposed as fire-driven alternative vegetation states
 (AVS): while high fire frequency would promote the stability of pyrophilic
 shrublands, the absence fires would stabilize pyrophobic forests. However,
 to assert that they are AVS we need to demonstrate that the
 fire-vegetation feedbacks occur under the same environmental conditions.
 We aimed to (i) identify to what extent Nothofagus forests and shrublands
 occur in the same environmental conditions across the temperate Andes and
 (ii) to understand how the fire regime explains the distribution patterns
 of these states. We used global environmental databases and local fire
 data to (i) estimate the environmental niche overlap of forests and
 shrublands, and (ii) obtain an indicator of the fire activity at
 micro-basin scale (percentage of cumulative burned area of forests and
 shrublands relative to the burnable area; PBA). The environmental niches
 of forests and shrublands overlapped by more than 70%. Shrublands become
 more frequent as PBA increases, suggesting that stabilizing
 fire-vegetation feedbacks promote their persistence. Our results provide
 broad-scale evidence of fire-driven AVS beyond the tropics.
description: # Data from: Fire-driven alternative vegetation states in temperate Andes
 [https://doi.org/10.5061/dryad.crjdfn3cc](https://doi.org/10.5061/dryad.crjdfn3cc) ## Description of the data and file structure Below you will find the following files: 1\) "code.txt" 2\) "pts.txt" 3\) "pts_pba.txt". And following rasters: "PC1.tif", "PC2.tif" and "PC3.tif". **File "code.txt". Data description** It contains the R script to perform all the analyses described in the article. For this, the files "pts.csv" and "pts_pba.csv" will be used. A detailed workflow on the analyses are provided in the script. **File "pts.txt". Data description** This file contains 10,000 random points with environmental information (climate, soil and topography) for N. pumilio forests and N. antarctica shrublands. With the environmental information, a Principal Component Analysis (PCA) will be carried out to subsequently model the ecological niches of the *Nothofagus pumilio* forest and the *Nothofagus antarctica* shrubland and their niche overlap. Columns: * id: unique identifier * sp: vegetation type. Nant: *N. antarctica shrublands*; Np: *N. pumilio* forest * cat_fire: micro-basin fire regime (No, Low, High) * sp_cat: fire regime category of each observation * x: longitude (geographical coordinates) WGS 84 * y: latitude (geographical coordinates) WGS 84 * MImin: Minimum monthly climate moisture index (kg m-2 month-1) (1) * NGD5: Number of growing degree days &gt; 5° C (1) * pH: soil pH in H2O (100-200 cm depth) (2) * CEC: Soil cation exchange capacity (mmol+/kg) (100 - 200 cm depth) (2) * Corg: Soil organic carbon (dg/kg) (100 - 200 cm depth) (2) * SWC: Soil volumetric water content at -33 kPa (%) (138 - 229 cm depth) (3) * elev: elevation (m a.s.l.) (4) * TRI: Terrain ruggedness index (m) (4) Data were collected from the following databases: (1) CHELSA (Karger et al. 2017): [https://envicloud.wsl.ch/#/?prefix=chelsa%2Fchelsa_V2%2FGLOBAL%2F](https://envicloud.wsl.ch/#/?prefix=chelsa%2Fchelsa_V2%2FGLOBAL%2F) (2) SoilGrids250 (Hengl et al. 2017): [https://soilgrids.org/](https://soilgrids.org/) (3) Global Soil Dataset for Earth System Modelling (Shangguan et al. 2014): [http://globalchange.bnu.edu.cn/research/soilw](http://globalchange.bnu.edu.cn/research/soilw) (4) IDE, Chile (TRI was derived from elev): [https://www.geoportal.cl/geoportal/catalog](https://www.geoportal.cl/geoportal/catalog) **File "pts_pba.txt". Data description** This file contains 10,000 random points generated within the geographical niche overlap zones of *N. pumilio* forest and *N. antarctica* shrublands. Each point contains its geographic coordinates, vegetation type and the percentage of burned area (PBA) of the micro-basin (PBA) within which each point is located are detailed. These data will be used to compare the distribution of forest and shrubland frequencies across the PBA. Details are described in the methods section of the article. Columns: * id: unique identifier * lon: longitude (geographical coordinates; WGS 84) * lat: latitude (geographical coordinates; WGS 84) * sp: vegetation type. Nant: *N. antarctica shrublands*; Np: *N. pumilio* forest * pba: percentage of burned area of the micro-basin **Raster PC1, PC2 and PC3:** These rasters were created and used for the geographic projection of N. pumilio and N. antarctica niches. The spatial resolution is 12.5 m (pixel size). With this, the geographic overlap zones of both niches were identified. The 10,000 random points of the dataset "pts_pba.csv" were generated in this zone of geographic overlap. The procedure for the geographic projection of the niches is described in the R script. ## Code/Software R.4.2.3 version was used.