Forest assessment and management involves the analysis of features of the landscape in relation to any disturbance. The multi temporal analysis of forest evolution is a critical issue to understand forest conditions in the past and the potential future on a global climate change context. For example, to analyze forest conditions of burn areas or to analyse the evolution of the regeneration after fire. Also, the states of forest decline are becoming more common in Mediterranean forests, induced, among other tfactors by climate change. Those processes are associated with pine mortality have been related to water stress in conifer forest at various locations in central and southern peninsula.

  Remote sensing data, particularly the use of satellite images has been proposed as the best alternative to assess structural variables and other ecophysiological variables at the regional landscape. A number of studies have shown relationships between LAI and chlorophyll concentration in vegetation indices derived from the visible and near infrared.

  The sensors MODIS, Chris Proba and Landsat TM and ETM + provide the ability to analyze these variables in long temporal, essential tool for studying the evolution of forests. Previous research has shown that it is possible to evaluate and quantify biophysical variables using time series of MODIS, Chris Proba and Landsat images. However, such studies are still scarce in Mediterranean forest ecosystems, and particularly in open canopies covering large areas in countries of the Mediterranean Basin. 

  Treesat lab is focused on the evaluation of multitemporal vegetation change analysis mainly disturbed by forest fire and forest declain processes.

 The image processing consists on a geo-referenced images (with no nearest neighbors), radiometric correction, atmospheric correction (by FLAASH) and radiometric standard-ization of the series (by iMAD). Different vegetation indices related with biophysical parameters and thermal data related to water stress is analyzed.

Figure 1. Evolution of stomata conductance in pinus nigra .

  The final product is the vegetation change mapping over the time image serie. Based on these mapping results, we perform a complete ecological analisis of the effects of the disturbation processes on the environment.

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  References

Hernandez-Clemente, R., Cerrillo, R. M., Hernandez-Bermejo, J. E., Royo, S. E. & Kasimis, N. A. (2009). Analysis of Postfire Vegetation Dynamics of Mediterranean Shrub Species Based on Terrestrial and NDVI Data. ENVIRONMENTAL MANAGEMENT, 43(5), 876-887.

Hernández-Clemente, R., Cerrillo, R. M. & Gitas, I. Z. (2009). Monitoring post-fire regeneration in Mediterranean ecosystems by employing multitemporal satellite imagery. INTERNATIONAL JOURNAL OF WILDLAND FIRE, 18(6), 648-658