IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Current distribution of Ecosystem Functional Types in the Iberian Peninsula
Autor/es:
. ALCARAZ D., PARUELO, JM AND CABELLO J
Revista:
GLOBAL ECOLOGY AND BIOGEOGRAPHY
Referencias:
Año: 2006 p. 200 - 210
ISSN:
0960-7447
Resumen:
ABSTRACT
Aim To examine the geographical patterns of the interception of photosynthetically
active radiation by vegetation and to describe its spatial heterogeneity through the
definition of ecosystem functional types (EFTs) based on the annual dynamics of the
Normalized DifferenceVegetation Index (NDVI),a spectral index related to carbon gains.
Location The Iberian Peninsula.
Methods EFTs were derived from three attributes of the NDVI obtained from
NOAA/AVHRR sensors: the annual integral (NDVI-I), as a surrogate of primary
production, an integrative indicator of ecosystem functioning; and the intra-annual
relative range (RREL) and month of maximum NDVI (MMAX), which represent
key features of seasonality.
Results NDVI-I decreased south-eastwards. The highest values were observed in the
Eurosiberian Region and in the highest Mediterranean ranges. Low values occurred
in inner plains, river basins and in the southeast. The Eurosiberian Region and
Mediterranean mountains presented the lowest RREL, while Eurosiberian peaks,
river basins, inner-agricultural plains, wetlands and the southeastern part of
Iberia presented the highest. Eurosiberian ecosystems showed a summer maximum
of NDVI, as did high mountains, wetlands and irrigated areas in the Mediterranean
Region. Mediterranean mountains had autumnearly-winter maxima, while semi-arid
zones, river basins and continental plains had spring maxima. Based on the behaviour
in the functional traits, 49 EFTs were defined.
Main conclusions The classification, based on only the NDVI dynamics, represents
the spatial heterogeneity in ecosystem functioning by means of the interception of
radiation by vegetation in the Iberian Peninsula. The patterns of the NDVI attributes
may be used as a reference in evaluating the impacts of environmental changes. Iberia
had a high spatial variability: except for biophysically impossible combinations (high
NDVI-I and high seasonality), almost any pattern of seasonal dynamics of radiation
interception was represented in the Peninsula.The approach used to define EFTs opens
the possibility of monitoring and comparing ecosystem functioning through time.
Keywords
AVHRR/NOAA, classification, ecosystem functioning, land-use change, Normalized
Difference Vegetation Index (NDVI), regional analysis, remote sensing.