The effect of sanitation cutting treatment on the spectral signature pattern of oak decline forests

Document Type : Research Paper

Authors

1 M.Sc. of Forestry, Faculty of Natural Resources, University of Kurdistan, I. R. Iran

2 2Associate Prof., Dept. of Forestry & the Center for Research & Development of Northern Zagros Forestry, University of Kurdistan, I. R. Iran

3 The Late Associate Prof., Dept. of Forestry & the Center for Research & Development of Northern Zagros Forestry, University of Kurdistan, I. R. Iran

Abstract

One of the problems of Zagros forests is the phenomenon of oak dieback, that its control is one of the important factors to prevent the destruction of forests. One of the proposed solutions to control this phenomenon is implementation of sanitary cutting. Remote sensing data has made it possible to monitor the areas involved in this phenomenon. The purpose of this study was to investigate the spectral behavior of exposed dieback forests before and after sanitary cutting in Guilan_e_Gharb forests. To monitor the pattern of spectral behavior, Landsat 8 satellite images were used from one year before sanitary cutting (2013) to 2018. After atmospheric correction of satellite images, NDVI, WDVI, SAVI and NDWI vegetation indices were prepared using spectral ratios of the main bands. A total of 30 points were selected scattered throughout the region and the spectral value of near-infrared band and vegetation indices were extracted at the selected points. The results showed that the spectral behavior had an upward trend until the last year of monitoring. The results of comparison of means test on the data of 2013-2018 showed that the differences between the means of all bands were statistically significant. Although the spectral behavior of vegetation indices is also affected by climate change and rainfall, but due to the increasing trend of near-infrared and vegetation indices during the years after sanitation cutting, a large part of the changes can be contributed tothe result of sanitary cutting and improvement of the forest conditions.

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