| NZ {disdat} | R Documentation |
New Zealand species distribution data
Description
Species occurrence data for 52 vascular plant species - mostly trees and shrubs from indigenous forests - in New Zealand (NZ), and associated environmental data. Full details of the dataset are provided in the reference below. There are four data sets with training (po and bg) and test (pa, env) data:
po (training data) includes site names, species names, coordinates, occurrence ("1" for all, since all are presence records), group (plant), and site values for 13 environmental variables (below).
bg (training data) has 10000 sites selected at random across the study region. It is structured identically to po, with "0" for occurrence (not implying absence, but denoting a background record in a way suited to most modelling methods) and NA for group.
env (testing data) includes group, site names, coordinates, and site values for 13 environmental variables (below), at 19120 sites. These data are suited to making predictions.
pa (testing data) includes group, site names, coordinates, and presence-absence records, one column per species. The sites are identical to the sites in env. This file is suited to evaluating the predictions made to env.
Raster (gridded) data for all environmental variables are available - see the reference below for details.
The coordinate reference system of the x and y coordinates is New Zealand Map Grid (NZMG), Datum: NZGD49 (New Zealand Geodetic Datum 1949), Ellipsoid: International 1924 (EPSG:27200).
The vignette provided with this package provides an example of how to fit and evaluate a model with these data.
Environmental variables:
| Code | Description | Units | Type |
| age | 3 classes (0 to 2): <2000, 2000-postglacial (app. 30,000), and pre-glacial | number (category) | Categorical |
| deficit | Mean October vapor pressure deficit at 0900 hours | kPa | Continuous |
| dem | Elevation | meters | Continuous |
| hillshade | Hill shading (as surrogate for slope and aspect) | index of brightness | Continuous |
| mas | Mean annual solar radiation | Mj/m2/day | Continuous |
| mat | Mean annual temperature | degrees C * 10 | Continuous |
| r2pet | Average monthly ratio of rainfall and potential evapotranspiration (ratio) | none | Continuous |
| rain | annual precipitation | mm | Continuous |
| slope | Slope | degrees | Continuous |
| sseas | Solar radiation seasonality | dimensionless | Continuous |
| toxicats | Toxic Cations in classes: 0=low, 1=intermediate, 2=high | number (category) | Categorical |
| tseas | Temperature seasonality | degrees C | Continuous |
| vpd | Mean October vapor pressure deficit at 9 AM | kPa | Continuous |
Source
Environmental predictors provided by Jake Overton. Species data supplied by Jake Overton and Susan Wiser, from Allan Herbarium and National Vegetation Survey databank.
See the reference below for further details on source, accuracy, cleaning, and particular characteristics of these datasets.
References
Elith, J., Graham, C.H., Valavi, R., Abegg, M., Bruce, C., Ferrier, S., Ford, A., Guisan, A., Hijmans, R.J., Huettmann, F., Lohmann, L.G., Loiselle, B.A., Moritz, C., Overton, J.McC., Peterson, A.T., Phillips, S., Richardson, K., Williams, S., Wiser, S.K., Wohlgemuth, T. & Zimmermann, N.E., (2020). Presence-only and presence-absence data for comparing species distribution modeling methods. Biodiversity Informatics 15:69-80.
Examples
nz_po <- disPo("NZ")
nz_bg <- disBg("NZ")
nz_pa <- disPa("NZ")
nz_env <- disEnv("NZ")
x <- disData("NZ")
sapply(x, head)
disCRS("NZ")