Abstract
Carbon and nitrogen storage in exotic Halophila stipulacea were compared to that in native Posidonia oceanica and Cymodocea nodosa meadows and adjacent unvegetated sediments of the Eastern Mediterranean Sea and to that in native H. stipulacea of the Red Sea at sites with different biogeochemical conditions and level of human pressure. Exotic H. stipulacea possessed considerable storing capacity, with 2-fold higher Corg stock (0.71 ± 0.05 kg m−2 in the top 20 cm of sediment) and burial (14.78 gCorg m−2 y−1) than unvegetated areas and C. nodosa meadows and, surprisingly, comparable to P. oceanica. N (0.07 ± 0.01 kg m−2) and Cinorg (14.06 ± 8.02 kg m−2) stocks were similar between H. stipulacea and C. nodosa or unvegetated sediments, but different to P. oceanica. Corg and N stocks were higher in exotic than native H. stipulacea populations. Based on isotopic mixing model, organic material trapped in H. stipulacea sediments was mostly allochthonous (seagrass detritus 17% vs seston 67%). Corg stock was similar between monospecific and invaded C. nodosa meadows by H. stipulacea. Higher stocks were measured in the higher human pressure site. H. stipulacea introduction may contribute in the increase of carbon sequestration in the Eastern Mediterranean.
Highlights
Biological invasion ranks among the most important components of global change, undermining the structure and function of native ecosystems[1]
The exotic H. stipulacea meadows studied here supported notable sedimentary Corg stocks compared to native seagrass, as well as to adjacent unvegetated sediments
Higher stocks in seagrass compared to bare sediments has been reported elsewhere, with 3 to 11-fold higher Corg stocks of P. sinuosa meadows in Australia[27] and 2 to 4-fold higher stocks of Thalassia testudinum and Halodule wrightii meadows in Gulf of Mexico[26] than the corresponding bare sediments
Summary
Biological invasion ranks among the most important components of global change, undermining the structure and function of native ecosystems[1]. H. stipulacea differs in most of the aforementioned traits from the two native seagrass species of the Mediterranean, P. oceanica and C. nodosa, forming meadows of higher density but of lower below-ground biomass and production than the latter[24,25].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
