Ecosystem functioning of protected and altered Mediterranean environments: A remote sensing classification in Doñana, Spain

FERNANDEZ, N.; PARUELO, JOSÉ; DELIBE, M.

REMOTE SENSING OF ENVIRONMENT

ELSEVIER SCIENCE INC

Año: 2009 vol. 114 p. 211 - 220

0034-4257

Spatial heterogeneity in ecosystem functioning is a key component of ecological variability requiring specialattention in the context of global change. A large history of human use has produced high physiognomicheterogeneity in Mediterranean ecosystems. However, the consequences for ecosystem functioning remaininsufficiently understood. We analyzed spectral indicators of matter and energy fluxes in the land surface toclassify the functional ecosystem heterogeneity in a Mediterranean region covering different managementhistories and protection types. We specifically analyzed the spatial variability in seasonal and annualpatterns in the Normalized Difference Vegetation Index (NDVI), surface temperature (Ts) and albedo fromfive Landsat ETM images. Then we classified numerically this variability into ecosystem functional types(EFTs) and explored their seasonal dynamics in terms of photosynthetic radiation absorption andevapotranspiration. We identified eight main EFTs with ecologically relevant differences includingcontrasting dynamics in fPAR seasonality, great variation in incoming radiation reflection and differingevapotranspiration rates, particularly during the water-limitation period. Functional variability in naturalvegetation mostly consisted in dissimilar annual rates of NDVI and albedo, whereas differences in seasonalitywere more evident in transformed areas. Similarly, the spatial distribution of EFTs was partly associated toprotection, with two EFTs exclusive of protected areas and comparatively higher functional diversity inhumanized areas. Landform effects on water availability in protected areas and human activities underdifferent ecological settings were seemingly responsible for the large functional diversity of the region. Weadvocate for the explicit incorporation of multifunctional ecosystem heterogeneity in ecosystem manage-ment and monitoring designs