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| Titel |
Responses of woody species to spatial and temporal ground water changes in coastal sand dune systems |
| VerfasserIn |
C. Máguas, K. G. Rascher, A. Martins-Loução, P. Carvalho, P. Pinho, M. Ramos, O. Correia, C. Werner |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 8, no. 12 ; Nr. 8, no. 12 (2011-12-22), S.3823-3832 |
| Datensatznummer |
250006259
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| Publikation (Nr.) |
 copernicus.org/bg-8-3823-2011.pdf |
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| Zusammenfassung |
| In spite of the relative importance of groundwater in costal dune systems,
studies concerning the responses of vegetation to ground water (GW)
availability variations, particularly in Mediterranean regions, are scarce.
Thus, the main purpose of this study is to compare the responses of
co-occurring species possessing different functional traits, to changes in
GW levels (i.e. the lowering of GW levels) in a sand dune ecosystem. For
that, five sites were established within a 1 km2 area in a
meso-mediterranean sand dune ecosystem dominated by a Pinus pinaster forest. Due to natural topographic variability and anthropogenic GW exploitation, substantial variability in depth
to GW between sites was found. Under these conditions it was possible to
identify the degree of usage and dependence on GW of different plant species
(two deep-rooted trees, a drought adapted shrub, a phreatophyte and a
non-native woody invader) and how GW dependence varied seasonally and
between the heterogeneous sites. Results indicated that the plant species
had differential responses to changes in GW depth according to specific
functional traits (i.e. rooting depth, leaf morphology, and water use
strategy). Species comparison revealed that variability in pre-dawn water
potential (Ψpre) and bulk leaf δ13C was related to
site differences in GW use in the deep-rooted (Pinus pinaster, Myrica faya) and phreatophyte (Salix repens)
species. However, such variation was more evident during spring than during
summer drought. The exotic invader, Acacia longifolia, which does not possess a very deep
root system, presented the largest seasonal variability in Ψpre
and bulk leaf δ13C. In contrast, the response of Corema album, an endemic
understory drought-adapted shrub, seemed to be independent of water
availability across seasons and sites. Thus, the susceptibility to lowering
of GW due to anthropogenic exploitation, in plant species from sand dunes,
is variable, being particularly relevant for deep rooted species and
phreatophytes, which seem to depend heavily on access to GW. |
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