Abstract

Environmental change and socio-economic pressure are expected to have significant impacts on northern Alborz vegetation, particularly along ecotone such as the treeline. Remote sensing may be well suited to monitoring recent changes across the treeline because it captures integrated changes of all vegetation life forms over large spatial extents. This research examines treeline vegetation composition and change along the Nojmeh treeline using a high resolution, enhanced thematic mapper (ETM⁺) 2000. In this paper, we investigate the use of satellite data to produce a classification of a treeline ecotone in Northern Alborz Mountains which has supported with the field investigation as ground truth data collected in the summers from 2008 to 2010. The maximum correlation is related to the bands 3 and 4 of Landsat ETM⁺ with shrubs canopy cover that indicated in r of 0.34 and 0.37, respectively. The maximum rate of correlation respect to the indices were recognized for the vegetation cover of moisture stress index (MSI) for forbs cover (r = 0.62). The ratio vegetation index (RVI) for grasses cover was indicated (r = 0.53). In conclusion, the results are specified that the ETM⁺ sensor is the significant data with the elevated competence to discrimination of ecotone using vegetation indices.

Key words: Electromagnetics, satellite, classification, ecotone, Alborz, Iran.

Abbreviation

MSI, Moisture stress index; RVI, ratio vegetation index; ETM⁺, enhanced thematic mapper; MSS, landsat-multi spectral scanner; TM, thematic mapper.