BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
Understanding plant drought resistance in a Mediterranean coastal sand dune ecosystem: differences between native and exotic invasive species

Participants in the publication
Cristina Antunes (Author)
Ana Júlia Pereira (Author)
Patrícia Fernandes (Author)
Margarida Ramos (Author)
Dep. Biologia Vegetal
cE3c
Lia Ascensão (Author)
Dep. Biologia Vegetal
CESAM
Otília Correia (Author)
Dep. Biologia Vegetal
cE3c
Cristina Máguas (Author)
Dep. Biologia Vegetal
cE3c

Summary
Abstract\\\\nAims\\\\nMediterranean coastal dunes are habitats of great conservation interest, with a distinctive and rich flora. In the last century, Acacia spp., native from Australia, have been introduced in Portugal, with the objective of stabilizing sand dunes, and since have become dominant in numerous sand dune habitats. This invasion process led to the reduction of native plant species richness, changed soil characteristics and modified habitat’s microclimatic characteristics. The aim of this research was to typify and compare, in Mediterranean sand dune ecosystems, the ecophysiological responses to drought of Helichrysum italicum and Corema album, two native species, and Acacia longifolia, an exotic invasive species. We addressed the following specific objectives: (i) to compare water relations and water use efficiencies, (ii) to evaluate water stress, (iii) to assess water use strategies and water sources used by plants and (iv) to evaluate the morphological adaptations at leaf and phyllode level.\\\\n\\\\nMethods\\\\nIn order to obtain an integrative view of ecophysiological patterns, water relations and performance measuring methods have been applied: predawn (ψPD) and midday (ψMD) water potential, chlorophyll a fluorescence, oxygen isotopic composition of xylem, rain and groundwater (δ18O) and leaf carbon isotopic discrimination (Δ13C). The leaf characteristics of the three species, as well as the histochemistry of non-glandular trichome cell walls, were also studied to identify morpho-traits related to drought resistance.\\\\n\\\\nImportant Findings\\\\nThe results support our initial hypothesis: although A. longifolia clearly possesses a degree of resistance to water stress, such ability is provided by a different water strategy, when compared to native species. Natives relied on morphological adaptations to restrict water loss, whereas the invasive species adjusted the water uptake as a way to balance their limited ability of restricting water loss. We corroborate that woody native species (i) have a conservative water-saving strategy and minor seasonal variations relative to invasive species, (ii) use enriched water sources during drought periods, indicating different water sources and root systems comparing with invasive species and (iii) present drought leaf morpho-functional adaptations related with limiting water loss. Comparing the physiological performance of invasive and native species can offer causal explanations for the relative success of alien plant invasions on sand dunes ecosystems.


Where published
Journal of Plant Ecology

Publication Identifiers
ISSN - 1752-9921

Publisher
Oxford University Press (OUP)



Document Identifiers
URL - http://dx.doi.org/10.1093/jpe/rtx014
DOI - https://doi.org/10.1093/jpe/rtx014

Rankings
Web Of Science Q2 (2018) - 2.282 - PLANT SCIENCES - SCIE
SCIMAGO Q1 (2018) - 0.813 - Plant Science

Keywords
ecophysiology water use strategy leaf mmorphology Acacia longifolia leaf morphology Corema album Helichrysum italicum