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European Quercus (Oak) Species Distribution with Environmental Predictors

Source: R/quercus.R
quercus.Rd

sf data frame with POINT geometry containing 6,728 records of eight European Quercus (oak) species and absence points, 1 response variable (see quercus_response), and 31 numeric predictors (see quercus_predictors). Use quercus_extra() to download the associated environmental raster.

Usage

data(quercus)

Format

An sf data frame with 6728 rows (species occurrences and absences) and 33 columns:

Response variable (1):

  • species: Character column with 9 levels: "absence" (background absence points), "Quercus robur" (English oak), "Quercus petraea" (Sessile oak), "Quercus ilex" (Holm oak), "Quercus cerris" (Turkey oak), "Quercus faginea" (Portuguese oak), "Quercus pubescens" (Downy oak), "Quercus pyrenaica" (Pyrenean oak), "Quercus suber" (Cork oak).

Predictor variables - Bioclimatic (17):

WorldClim v2 bioclimatic variables (excludes bio8 and bio9):

  • bio1: Annual mean temperature (degrees C).

  • bio2: Mean diurnal range (degrees C).

  • bio3: Isothermality (bio2/bio7 * 100).

  • bio4: Temperature seasonality (standard deviation * 100).

  • bio5: Max temperature of warmest month (degrees C).

  • bio6: Min temperature of coldest month (degrees C).

  • bio7: Temperature annual range (degrees C).

  • bio10: Mean temperature of warmest quarter (degrees C).

  • bio11: Mean temperature of coldest quarter (degrees C).

  • bio12: Annual precipitation (mm).

  • bio13: Precipitation of wettest month (mm).

  • bio14: Precipitation of driest month (mm).

  • bio15: Precipitation seasonality (coefficient of variation).

  • bio16: Precipitation of wettest quarter (mm).

  • bio17: Precipitation of driest quarter (mm).

  • bio18: Precipitation of warmest quarter (mm).

  • bio19: Precipitation of coldest quarter (mm).

Predictor variables - NDVI (4):

  • ndvi_average: Average NDVI.

  • ndvi_maximum: Maximum NDVI.

  • ndvi_minimum: Minimum NDVI.

  • ndvi_range: NDVI range.

Predictor variables - Solar radiation (4):

  • sun_rad_average: Average solar radiation (kJ m-2 day-1).

  • sun_rad_maximum: Maximum solar radiation (kJ m-2 day-1).

  • sun_rad_minimum: Minimum solar radiation (kJ m-2 day-1).

  • sun_rad_range: Solar radiation range (kJ m-2 day-1).

Predictor variables - Land cover (3):

  • landcover_veg_bare: Percentage of bare ground.

  • landcover_veg_herb: Percentage of herbaceous vegetation.

  • landcover_veg_tree: Percentage of tree cover.

Predictor variables - Topography (2):

  • topographic_diversity: Number of unique combinations of elevation, slope, and aspect classes within a neighborhood.

  • topo_slope: Topographic slope in degrees.

Predictor variables - Human impact (1):

  • human_footprint: Human footprint index.

Geometry:

  • geometry: Point geometry (WGS84, EPSG:4326).

Source

Species occurrences:

Bioclimatic variables and solar radiation:

  • Fick, S.E. & Hijmans, R.J. (2017). WorldClim 2: new 1-km spatial resolution climate surfaces for global land areas. International Journal of Climatology, 37(12), 4302-4315. https://doi.org/10.1002/joc.5086

NDVI:

Land cover:

Elevation and topography:

  • Jarvis, A., Guevara, E., Reuter, H. I., & Nelson, A. D. (2008). Hole-filled SRTM for the globe: version 4, data grid. Web publication/site, CGIAR Consortium for Spatial Information. https://srtm.csi.cgiar.org

Human footprint:

See also

Other quercus: quercus_extra(), quercus_predictors, quercus_response