2024-03-29T12:40:20Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1275342020-05-04T09:20:35Zcom_10261_75com_10261_6col_10261_454
2016-01-13T10:12:04Z
urn:hdl:10261/127534
Spatio-temporal dynamics of soil water in a semi-arid Mediterranean ecosystem: implications for plant dynamics and spatial pattern
Pueyo, Yolanda
Moret-Fernández, David
Arroyo, Antonio I.
Frutos Tena, Ángel de
Sáiz Bustamante, Hugo
López Alados, Concepción
Soil water presents high temporal and spatial variability in drylands. The temporal variability is determined by the
heterogeneous and unpredictable rainfall pattern in these ecosystems. The spatial variability is associated to the
well-known “source-sink” eco-hydrological dynamics occurring in drylands, related to the patchy vegetation and
bare soil structure with water run-off generated on the bare soil patches and water infiltration preferentially into
vegetated areas. These run-off – run-on systems has been extensively studied and the processes involved are well
known, including the role of different plant types capturing the water run-on, increasing infiltration and reducing
evaporation under plant canopies. However, integrative studies of hydrological and ecological processes in a whole
ecosystem during a prolonged time period are scarce, despite the relevance of this approach to understand the
role of hydrological processes (and what hydrological process are most important) determining plant dynamics
and spatial pattern. We present an eco-hydrological study conducted in a semiarid Mediterranean ecosystem in
the Middle Ebro Valley (NE Spain), where soil water content and patterns of plant establishment were followed
during 30 months in 4 microsites: open bare areas, under two shrub species (Salsola vermiculata and Artemisia
herba-alba) and one perennial grass species (Lygeum spartum). These 4 microsites represent the vast majority of
the land in the ecosystem under study. Water infiltration, photosynthetic photon flux and soil temperature were
also recorded in the 4 microsites. Simultaneously, seedling establishment and survival were recorded twice per
year in the same microsites. Lygeum spartum was the microsite with the largest increment in water infiltration, and
with the largest reduction in both solar radiation and soil temperature when compared with the measurement in the
open bare areas. However, soil water content after rainfall under the canopy of Salsola vermiculata was the largest,
indicating that canopy interception could be a less relevant process under the canopy of S. vermiculata than under
the canopy of L. spartum. Moreover, there was an interactive effect of the soil water content before rainfall and
the magnitude of the rainfall with the microsite (i.e. wet bare soils infiltrated more water than dry bare soils, being
this difference less relevant in the vegetated microsites). Patterns of seedling establishment and survival correlated
to patterns in soil water content, pointing out the relevance of the eco-hydrological spatio-temporal heterogeneity
in the dynamics and spatial pattern of plant communities. Seedling establishment occurs in the first centimetres of
soil, where competition for water (under Lygeum spartum) and evaporation (in the open bare soil areas) seems to
reduce the water availability for plant establishment.
2016-01-13T10:12:04Z
2016-01-13T10:12:04Z
2014-04-27
2016-01-13T10:12:09Z
póster de congreso
European Geosciences Union General Assembly (27 April – 02 May 2014, Vienna, Austria)
http://hdl.handle.net/10261/127534
eng
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