Agriculture Reference
In-Depth Information
Short Communication A
W
ATER
I
NTERACTIONS
B
ETWEEN
B
ARE
S
OIL AND
V
EGETATION IN
S
EMIARID
M
EDITERRANEAN
S
TEPPES
:
S
OME
N
EW
E
VIDENCES
David A. Ramírez
1,2
, Francisco Domingo
3,4
and Juan Bellot
1
1
Departamento de Ecología, Universidad de Alicante Ap. 99-E-03080, Alicante, Spain.
2
Laboratorio de Ecología de Procesos, Dpto. Biología, Universidad Nacional Agraria La
Molina, Ap.456, Lima, Perú
3
Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones
Científicas, 04001 Almería, Spain
4
Departamento de Biología Vegetal y Ecología, Escuela Politécnica Superior,
Universidad de Almería, 04120 Almería, Spain
A
BSTRACT
Bare soil forms an important part of the surface cover in Mediterranean arid and
semiarid areas dominated by
Stipa tenacissima
L. tussock grass. Some studies have
stressed the relevance of the spatial arrangement of this species in the improvement of
sediment dynamic and soil characteristics close to the tussock. Reciprocally, bare soil
condition has been considered as a key factor in the physiological performance of
S.
tenacissima
stands. On the other side, other studies have neglected the capacity of the
root system of this species to explore and consume resources from bare soil surrounding
the tussock. In the present work we show some evidences that suggest the importance of
bare soil near to the tussock in the water status of this species, especially in the high
water stress season. We have found that water gains in bare soil from water vapour
adsorption were highly coincident with the
S. tenacissima
stand transpiration.
Furthermore,
S. tenacissima
sub-populations living in rock outcrops with lower
connectivity with the surrounded bare soil showed higher signs of physiological water
stress than those stands in areas with more soil availability. We believe that an interaction
of water dynamics between bare soil and
S. tenacissima
tussocks would have to be
reconsidered to fully understand ecophysiology of this species.
