Spectral-Based Monitoring of Climate Effects on the Inter-Annual Variability of Different Plant Functional Types in Mediterranean Cork Oak Woodlands

Using remotely sensed data to estimate the biophysical properties of vegetation in woodlands is a challenging task due their heterogeneous nature. The objective this study was assess parameters different types (cork oak trees, shrubs and herbaceous vegetation) cork woodland through analysis temporal trends spectral indices (VIs). A seven-year database (from 2011 until 2017) situ observations collected with field spectroradiometer monthly basis used four VIs were derived, considered as proxies for several such biomass (Normalized Difference Vegetation Index—NDVI); chlorophyll content (MERIS Terrestrial Chlorophyll Index-MTCI), tissue water Water Index—NDWI) carotenoid/chlorophyll ratio (Photochemical Reflectance Index—PRI). During analyzed period, some key meteorological (precipitation, temperature, relative air humidity global radiation) site, aggregated at three time-lags (short period (30 d), medium (90 d) hydrological (HIDR)), relationship analyzed. results showed each index type. In NDVI NDWI, highly marked seasonal trend, whereas MTCI, it Cistus salvifolius, PRI, Ulex airensis that trend. Shrubs have large differences depending on species: shallow-rooted salvifolius higher variability than deep-rooted airensis. Our revealed importance temperature precipitation main climatic variables influencing VI studied types. This sets up relationships between climate Spectral are useful tools assessing impact vegetation, because using these makes easier monitor amount “greenness”, stress photosynthetic efficiency. Proximal remote sensing measurements fundamental correct use monitoring complex agroforest ecosystems, largely inform policies improve resilience drought, particularly Mediterranean region.