Mapping tree species in temperate deciduous woodland using time-series multi-spectral data
Authors: Hill, R.A., Wilson, A.K., George, M. and Hinsley, S.A.
Journal: Applied Vegetation Science
Volume: 13
Issue: 1
Pages: 86-99
eISSN: 1654-109X
ISSN: 1402-2001
DOI: 10.1111/j.1654-109X.2009.01053.x
Abstract:Questions: What is the optimum combination of image dates across a growing season for tree species differentiation in multi-spectral data and how does species composition affect overstorey canopy density? Location: Monks Wood, Cambridgeshire, eastern England, UK. Methods: Six overstorey tree species were mapped using five Airborne Thematic Mapper images acquired across the 2003 growing season (17 March, 30 May, 16 July, 23 September, 27 October). After image pre-processing, supervised maximum likelihood classification was performed on the images and on all two-, three-, four- and five-date combinations. Relationships between tree species composition and canopy density were assessed using regression analyses. Results: The image with the greatest tree species discrimination was acquired on 27/10 when the overstorey species were in different stages of leaf tinting and fall. In this image, tree species were mapped with an overall classification accuracy (OCA) of 71% (kappa 0.63). A similar OCA was achieved from the other four images combined (OCA 72%, kappa 0.64). The highest classification accuracy was achieved by combining three images: 17 March, 16 July, 27 October. This achieved an OCA of 84% (kappa 0.79), increasing to 88% (kappa 0.85) after a post-classification clump and sieve procedure. Canopy height and percentage cover of oak explained 72% of variance in canopy density. Conclusions: The ability to discriminate and map temperate deciduous tree species in airborne multispectral imagery is increased using time-series data. An autumn image supplemented with an image from both the green-up and full-leaf phases was optimum. The derived tree species map provides a more powerful ecological tool for determining woodland structural/ compositional relationships than field-based measures. © 2009 International Association for Vegetation Science.
Source: Scopus
Mapping tree species in temperate deciduous woodland using time-series multi-spectral data
Authors: Hill, R.A., Wilson, A.K., George, M. and Hinsley, S.A.
Journal: APPLIED VEGETATION SCIENCE
Volume: 13
Issue: 1
Pages: 86-99
eISSN: 1654-109X
ISSN: 1402-2001
DOI: 10.1111/j.1654-109X.2009.01053.x
Source: Web of Science (Lite)
Mapping tree species in temperate deciduous woodland using time-series multi-spectral data.
Authors: Hill, R.A., Wilson, A.K., George, M. and Hinsley, S.A.
Journal: Applied Vegetation Science
Volume: 13
Pages: 86-99
ISSN: 1402-2001
DOI: 10.1111/j.1654-109X.2009.01053.x
Abstract:Questions: What is the optimum combination of image dates across a growing season for tree species differentiation in multi-spectral data and how does tree species composition affect overstorey canopy density? Location: Monks Wood, Cambridgeshire, eastern England.
Methods: Six overstorey tree species were mapped using five Airborne Thematic Mapper images acquired across the 2003 growing season (17/03, 30/05, 16/07, 23/09, 27/10). After a series of image pre-processing procedures, supervised Maximum Likelihood classification was performed on the individual images and on all 2-, 3-, 4-, and 5-date combinations. Relationships between tree species composition and canopy density were assessed using regression analyses.
Results: The image with the greatest tree species discrimination was acquired on 27/10 when the overstorey species were in different stages of leaf tinting and fall. In this image, tree species were mapped with an overall classification accuracy (OCA) of 71% (Kappa 0.63). A similar OCA was achieved from the four other images combined (OCA 72%, Kappa 0.64). The highest classification accuracy was achieved by combining three images: 17/03, 16/07, 27/10. This achieved an OCA of 84% (Kappa 0.79), which increased to 88% (Kappa 0.85) after a post-classification clump and sieve procedure. A combination of canopy height and the percentage cover of oak explained 72% of variance in canopy density. Conclusions: The ability to discriminate and map temperate deciduous tree species in airborne multi-spectral imagery is increased using time-series data. An autumn image supplemented with an image from both the green-up and full-leaf phases was optimum. The derived tree species map provides a more powerful ecological tool for determining woodland structural/compositional relationships than field-based measures.
Source: Manual
Preferred by: Ross Hill