INVESTIGADORES
PARUELO Jose Maria
artículos
Título:
Baseline characterization of major Iberian vegetation types based on the NDVI dynamics
Autor/es:
ALCARAZ, D.; PARUELO, J. M.; CABELLO, J.
Revista:
PLANT ECOLOGY
Editorial:
SPRINGER
Referencias:
Año: 2009 vol. 202 p. 13 - 292
ISSN:
1385-0237
Resumen:
Abstract We
present an approach to derive base-
line
conditions for the radiation intercepted by
vegetation
in the largest remaining patches of homo-
geneous
vegetation of the Iberian Peninsula. These
baseline
conditions can serve as a reference to assess
environmental
changes. We also characterized the
major
vegetation types of the Peninsula in the
functional
space defined by the
NDVI dynamics
and analyzed
the climatic controls of NDVI dynam-
ics. We
analysed the attributes of the NDVI seasonal
dynamics:
annual mean (NDVI-I), relative range
(RREL),
NDVI maximum and minimum values
(MAX and
MIN), months of MAX and MIN (MMAX
and MMIN),
and their inter-annual variabilities
(19821999).
We selected as reference sites only
homogeneous
pixels occupied by natural vegetation.
We
described their relationship with climatic vari-
ables using
regression models. NDVI-I and RREL
captured
most of the variability of the NDVI annual
profile.
Eurosiberian vegetation types were more
productive,
with winter minima and summer maxima.
Mediterranean
vegetation had summer minima and
maxima
distributed from autumn to spring. Inter-
annual
differences (higher in the Mediterranean) were
low for
NDVI-I and MAX and high for RREL and
MIN.
Precipitation was the main driver of NDVI-I for
the
Mediterranean pixels while temperature con-
strained it
in the Eurosiberian ones. Seasonality
(RREL) was
associated with winter temperatures in
Eurosiberian
areas and with summer drought in
Mediterranean
ones. The Iberian vegetation types
mainly
differed in terms of total production and
seasonality.
Such differences were related to mean
and
inter-annual variation in precipitation and tem-
perature
associated with the Eurosiberian and
Mediterranean
climate zones. The NDVI dynamics
allowed us
to identify a functional signature for each
vegetation
type which captures differences that go
beyond
their range of climatic factors. Our baseline
descriptions,
based on a common approach to char-
acterize
vegetation functioning, are proposed as
reference
situations to evaluate the impact of envi-
ronmental
changes on the remaining large patches of
single
major natural and seminatural vegetation
types.