Salt application as an effective measure to control ruderal invaders threatening endangered halophytic plant species. Issue 3 (20th November 2012)

• Record Type: Journal Article
• Authors: Khan, Zeeba; Albrecht, Matthias; Traveset, Anna; Middleton, Beth
• Is Part Of: Applied vegetation science. Volume 16:Issue 3(2013:Jul.)
• Page Start: 448
• Page End: 456
• Publication Date: 2012-11-20
• Subjects: Plant ecology -- Periodicals; Plant communities -- Periodicals; Plant populations -- Periodicals; Nature -- Effect of human beings on -- Periodicals; 581.705
• DOI: 10.1111/avsc.12007
• Languages: English
• ISSNs: 1402-2001

Abstract

<abstract abstract-type="main" id="avsc12007-abs-0001"> <title>Abstract</title> <sec id="avsc12007-sec-0001" sec-type="section"> <title>Questions</title> <p>How does salinity affect germination, seedling performance and survival of the critically endangered <italic>Limonium barceloi, </italic> compared to ruderal species invading its salt marsh habitat? Is salt application an effective management tool for controlling invaders and favouring endangered halophytes?</p> </sec> <sec id="avsc12007-sec-0002" sec-type="section"> <title>Location</title> <p>Ses Fontanelles, Mallorca, Balearic Islands, Spain.</p> </sec> <sec id="avsc12007-sec-0003" sec-type="section"> <title>Methods</title> <p>The germination of seeds of <italic>L. barceloi</italic> and nine ruderal species was tested in five salinity levels (0–37 g·L<sup>−1</sup>), and also in freshwater after a pre‐treatment with seawater. The ruderal study species were: <italic>Asphodelus fistulosus, Avena barbata</italic>, <italic> Geranium molle</italic>, <italic> Hypochoeris achyrophorus</italic>, <italic> Oryzopsis miliacea</italic>, <italic> Plantago coronopus, Reichardia picroides, Sonchus asper</italic> and <italic>Sonchus tenerrimus</italic>. Two salt concentration levels (18 and 37 g·L<sup>−1</sup>) were applied twice monthly, weekly or twice weekly to examine the effect of salt irrigation schemes on the performance and seedling survival of <italic>L. barceloi</italic> compared to two of the principal species invading these salt marshes, <italic>S. tenerrimus</italic> and <italic>A. fistulosus</italic>.</p> </sec> <sec id="avsc12007-sec-0004" sec-type="section"> <title>Results</title> <p>Germination of <italic>L. barceloi</italic> and most ruderal species was highest at low salinity (0–8 g·L<sup>−1</sup>). Seeds of <italic>L. barceloi, A. fistulosus</italic> and <italic>S. tenerrimus</italic> were also able to germinate at the highest salinity level, in contrast to the other species. Germination in freshwater after seawater pre‐treatment was highest in <italic>L. barceloi</italic> (72 ± 6%). Seedling performance and survival of <italic>A. fistulosus</italic> and <italic>S. tenerrimus</italic> decreased with frequency and concentration of the salt treatment. An application of 37 g·L<sup>−1</sup> salt twice a week reduced seedling survival of <italic>A. fistulosus</italic> and <italic>S. tenerrimus</italic> by 83.3 and 91.6%, respectively. In contrast, 100% of the <italic>L. barceloi</italic> seedlings survived and showed similar performance among treatments.</p> </sec> <sec id="avsc12007-sec-0005" sec-type="section"> <title>Conclusions</title> <p> <italic>Limonium barceloi</italic> had higher seedling growth and survival than ruderal invaders when salinity levels were high (37 g·L<sup>−1</sup>). Nevertheless, at lower salinity, ruderal species may germinate and grow better and thus salinity level changes may represent a threat to the survival of this critically endangered species. Although further field testing is required, our experiments suggest that salt application could be an effective measure to protect <italic>L. barceloi</italic> and other endangered halophytic plant species from less salt‐tolerant invaders.</p> </sec> </abstract>