EarthEnv

Global, remote-sensing supported environmental layers for assessing status and trends in biodiversity, ecosystems, and climate

Global Habitat Heterogeneity

The datasets contain 14 metrics quantifying spatial heterogeneity of global habitat at multiple resolutions based on the textural features of Enhanced Vegetation Index (EVI) imagery acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS). For additional information about the metrics and the evaluations of their utility for biodiversity modeling, please see the associated journal article:

Tuanmu, M.-N. and W. Jetz. (2015) A global, remote sensing-based characterization of terrestrial habitat heterogeneity for biodiversity and ecosystem modeling. Global Ecology and Biogeography. DOI: 10.1111/geb.12365.

Dataset Details

Six first-order and 8 second-order texture measures are available at 30 arc-second (~1 km at the equator), 2.5 arc-minute (~5 km) and 12.5 arc-minute (~25 km) resolutions. The first-order texture measures are statistics describing the frequency distribution of EVI values and measureing compositional variability in EVI within an area. The second-order texture measures are statistics of the occurrence probabilities of different EVI combinations among pixel pairs within an area and thus also reflect spatial arrangement and dependency of the EVI values.

First-order texture measures

Metric Measure Value Range Expected Relationship with Heterogeneity
Coefficient of variation Normalized dispersion of EVI >=0 Positive
Evenness Evenness of EVI >=0; <=1 Positive
Range Range of EVI >=0 Positive
Shannon Diversity of EVI >=0; <=ln(max # of different EVI) Positive
Simpson Diversity of EVI >=0; <=1-1/(max # of different EVI) Positive
Standard deviation Dispersion of EVI >=0 Positive

Second-order texture measures

Metric Measure Value Range Expected Relationship with Heterogeneity
Contrast Exponentially weighted difference in EVI between adjacent pixels >=0 Positive
Correlation Linear dependency of EVI on adjacent pixels >=-1; <=1 Nonlinear
Dissimilarity Difference in EVI between adjacent pixels >=0 Positive
Entropy Disorderliness of EVI >=0 Positive
Homogeneity Similarity of EVI between adjacent pixels >=0; <=1 Negative
Maximum Dominance of EVI combinations between adjacent pixels >=0; <=1 Negative
Uniformity Orderliness of EVI >=0; <=1 Negative
Variance Dispersion of EVI combinations between adjacent pixels >=0 Positive

All data layers are in WGS84 projection and have a spatial extent from 85ºN - 60ºS and from 180ºW - 180ºE. The pixel values of the data layers should be mulitplied by 0.0001 to obtain the actual values of the metrics.

Dataset Download

Version 1.0

Metric 30 arc-second (1 km) 2.5 arc-minute (5 km) 12.5 arc-minute (25 km)
Coefficient of variation Download GeoTIFF Download GeoTIFF Download GeoTIFF
Evenness Download GeoTIFF Download GeoTIFF Download GeoTIFF
Range Download GeoTIFF Download GeoTIFF Download GeoTIFF
Shannon Download GeoTIFF Download GeoTIFF Download GeoTIFF
Simpson Download GeoTIFF Download GeoTIFF Download GeoTIFF
Standard deviation Download GeoTIFF Download GeoTIFF Download GeoTIFF
Contrast Download GeoTIFF Download GeoTIFF Download GeoTIFF
Correlation Download GeoTIFF Download GeoTIFF Download GeoTIFF
Dissimilarity Download GeoTIFF Download GeoTIFF Download GeoTIFF
Entropy Download GeoTIFF Download GeoTIFF Download GeoTIFF
Homogeneity Download GeoTIFF Download GeoTIFF Download GeoTIFF
Maximum Download GeoTIFF Download GeoTIFF Download GeoTIFF
Uniformity Download GeoTIFF Download GeoTIFF Download GeoTIFF
Variance Download GeoTIFF Download GeoTIFF Download GeoTIFF

Distribution

Creative Commons License
Global Habitat Heterogeneity Metrics Version 1 by Tuanmu & Jetz is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Permissions beyond the scope of this license may be available at http://www.earthenv.org/texture.html.

Dataset Citation

Tuanmu, M.-N. and W. Jetz. (2015) A global, remote sensing-based characterization of terrestrial habitat heterogeneity for biodiversity and ecosystem modeling. Global Ecology and Biogeography. DOI: 10.1111/geb.12365.

Contacts