Evaluation of drought effects on ecosystems functioning in Sierra Nevada
protected area (Andalusia, SE Spain) through vegetation indices time series.
Sergio David Aguirre García.
Sierra Nevada protected area is a biodiversity hot spot especially vulnerable to Climate Change, which is likely to undergo global change processes. Its strong altitudinal gradient and natural conditions make it an ideal place to experiment with methodologies that allow knowing and understanding the ecosystems functioning. The aim of this work is to know and understand how these Mediterranean ecosystems respond and evolve in the face of disturbances such as drought. Using as reference the 2005 drought
episode, a methodological scheme has been established to study the ecosystems stability by means vegetation indices (EVI) time series analysis, obtained from satellite images. The Breaks For Additive
Seasonal and Trend (BFAST) methodology has been applied to detect and estimate the moment in which the change is manifested, its magnitude and the recovery time of the ecosystem. These parameters have been interpreted in terms of ecosystem resistance and resilience, finding negative alterations in their functioning as a consequence of the disturbance, behavioral differences between ecosystems, spatial patterns in the whole territory at the moment and magnitude response and recovery time. The ecosystems resistance and resilience has been estimated, as well as some factors that condition their response to the drought. The methodology used has been adequate and effective, can be easily transferred to other protected areas and provide useful information on changes in the ecosystems functioning to help improve their resilience, so as to favor mitigation and adaptation to change.
Keywords: Global Change, Disturbance, Ecosystem Stability, Resistance, Resilience, Remote Sensing, EVI, BFAST