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Because band widths are narrow and the range of spectra wide,subtle differences in spectral features can be extracted and used for mapping physical and chemical properties of bare substrate with imaging spectroscopy.However,the use of spectral characteristics of substrates are not accessible if the substrate is covered by vegetation.In this study,we explored the feasibility of extracting spectral properties ofkarst substrates across an eco-environmental gradient covered with vegetation.Eco-environmental factors (slope,aspect,altitude,soil moisture,organic matter (SOC),pH and calcium carbonate content (Ca)) and vegetation biochemical materials were recorded simultaneously with the collection of vegetation reflectance spectra.Data collection took place during May 1-8,2008,which was the peak growing season.Sampling plots were randomly placed within a relatively homogeneous vegetation community across an eco-environmental gradient.We used t-tests and derivative reflectance spectra to analyze the vegetation spectral differences along the eco-environmental gradient,and Canonical correspondence analysis (CCA) was used to explore the relationship between vegetation spectra and eco-environmental factors.The results showed that there were significant differences between spectral features of the vegetation distributed in karst and non-karst regions.A combination of 1300-2500 nm reflectance bands and 400-700 nm first derivative spectra could delineate vegetation distributed in karst and non-karst regions.The CCA successfully assessed to what extent the variation of vegetation spectral features can be explained by associated eco-geo-environmental variables.It was found that soil moisture and calcium carbonate content had the most significant effects on vegetation spectral features in karst regions.Most sample plots were separated into two groups by the CCA ordination diagram according to the vegetation reflectance spectra.The CCA ordination successfully separated the vegetation spectral features along the main ecoenvironmental gradient of karst and non-karst regions.Vegetation spectra were thus well illuminated by the eco-environmental gradient in karst regions.Our study indicates that vegetation spectra is tightly linked to eco-environmental gradients,and that CCA is an effective method for studying the relationships among vegetation spectral features and eco-environmental variables.Employing a combination of spectral and spatial analysis,it is anticipated that imaging spectroscopy can be used for the interpretation and mapping of eco-environmental gradients covered with vegetation in karst regions.