Ecologia mediterranea 1999-25(2)

Tones et a!.
ABRIDGED ENGLISH VERSION
A study on the natural communities of Pinus halepensis
in the south of Spain (Andalusia) has been carried out. The
bibliographic information with data of interest about its
spontaneity in the whole Mediterranean basin (specially in
the Iberian peninsula) has been compiled. The edaphoxerophilous
character of this pine-woods in the study area has
been pointed out, having described a new phytosociological
association and a plant community: Junipero phaenieeae­
Pinetum halepensis and community of Ephedra jragilis and
Pinus halepensis.
The spontaneous formations of Pinus halepensis in the
Iberian peninsula develop on basic substrata, specially in the
mediterranean coastal provinces (Catalufia, Comunidad Valenciana,
Murcia and Baleares), reaching interior zones of
the Baetic ranges, Iberian System, Ebro valley and eastern
Pirenees. They mainly appear under Mediterraneanpluviestational-oceanic,
Mediterranean-xeric-oceanic and
Mediterranean-pluviestational-continental bioclimates,
ranging between thermomediterranean and mesomediterranean
thennotypes and from semi-arid to sub-humid ombrotypes,
sharing the areas occupied by shrub communities of
holly-oaks (Quereus caceirera L.), lentiscs (Pistaeia lentiscus
L.) or savines (Juniperus phoenicea L.) depending on
the substrata nature.
The iberian pine-woods of P. halepensis, take the case
of the iberic southeastern have been scarcely studied, though
they are one of the most characteristic elements in the plant
landscape. In spite of the physiognomic importance and their
widespread area, a large number of authors question the climacic
role of these woods in the Mediterranean region, even
stating that P. halepensis does not grow spontaneously in the
Western Mediterranean. Though there are several bibliographic
references in which a secondary and anthropic character
is assigned to this pine in woods and scrubs, it has
never been regarded as the main species in such communities.
INTRODUCCION
Pinus halepensis Mill. es un arbol generalmente
retorcido, de unos 12-14 m de altura media,
normalmente aparasolado, aunque puede llegar hasta
los 22-24 m en las mejores situaciones ecol6gicas.
Presenta una distribuci6n basicameitte circun­
mediteminea, formando bandas cercanas a la costa
donde no suele superar los 700-800 m de altitud, a
excepci6n de ciertas zonas de Africa del Norte donde
puede llegar hasta los 2000 m (Quezel, 1977, 1980).
Desde el punto de vista taxon6mico se trata de una
especie ecol6gica y geneticamente muy pr6xima a
Pinus brutia Ten. (Biger & Liphschitz, 1991) con el
que forma un grupo bien definido (grupo Halepenses).
Ampliamente extendido por todo el Mediterraneo
occidental, es sustituido hacia el oeste por su
vicariante Pinus brutia (Figura I). Aunque raramente
suelen coexistir ambas especies (Akman et aI, 1978),
en el caso de hacerlo, como ocurre en algunos distritos
136
Caracterizach5n de las pinares en el sur de la peninsula iberica
There are only a few botanists that have pointed out the
natural and authoctonous character of P. Iwlepensis in some
territories, either co-dominating with trees and shrubs or
dominating the community by itself.
In our study, bearing in mind the results of fossil and
subfossil registers of the last 15.000 years and the analysis
and taxonomic identification of charcoals. we show interesting
data about the spontaneous character of P. halepensis
in the Baetic area (southern peninsula) where it takes part of
edaphoxerophilous communities confined to the most thermic
and dry zones (sunny exposures) due to the lithological,
geomorphological and climatological territorial factors. The
widespread calcareous-dolomitic emergences allow the existence
of a sheer landscape with big rocky blocks where the
permeability of the substrata reduces the effects of the real
precipitations in the territory. Furthermore, the karstification
processes, break and crush the rocks causing hiperxeric environments
very suitable for the establishing of P. halepensis
pine-woods.
These pine-woods can also take place on marls (even
with a high content of gypsum) in extremely degradated
soils that accentuate the ombroclimatic xericity.This fact is
quite common in places with rains shades where the precipitations
coming from the Atlantic ocean are very reduced
because of the existence of high mountain boundaries.
Thus, P. halepensis (as other conifers) constitutes natural
formations in southern Iberian peninsula, specially in the
thermomediterranean and mesomediterranean belts, and at a
lesser extent in the inferior supramediterranean. In some
cases, a semi-arid territory rich in Neogenous-Quaternarian
deposits (marls, calcareous marls and conglomerates) with a
scarce water retention is optimum for the development of P.
halepensis. In the other hand, a rough geomorphology of
calcareous-dolomitic ranges may be the determining factor
for the establishing of these pine-woods, in this case under a
wider range of ombrotypes (semi-arid, dry and sub-humid).
de Grecia, en el sureste de Anatolia y en el Lfbano,
suelen formar hfbridos naturales (Panetsos, 1975). Las
poblaciones apartadas de Pinus halepensis en Asia
Menor y Cercano Oriente, al limite este de la Cuenca
Mediterranea, plantea curiosas cuestiones a cerca del
modelo de distribuci6n en el pasado y las rutas
migratorias (Barbero et ai, 1998).
En la Peninsula Iberica, las formaciones
espontaneas de Pinus halepensis aparecen sobre
sustratos basicos, principalmente en las provincias del
litoral mediterraneo (Cataluna, Comunidad
Valenciana, Murcia y Baleares), penetrando hacia el
interior en las sierras Beticas, Sistema Iberico, Valle
del Ebro y Pirineos orientales. Se distribuye
mayoritariamente en los bioclimas Mediterraneo
pluviestacional-oceanico, Mediterraneo xerico­
oceanico y Mediterraneo pluviestacional-continental
con ciertas penetraciones en el Templado oceanico­
submediterraneo (Rivas-Martinez, I 996a, 1996b).
Puesto que el factor determinante para su distribuci6n
ecologia mediterranea 25 (2) - /999