TY - JOUR
T1 - Gas exchange and isotopic signature of mangrove species in Southern Brazil
AU - Larcher, Leticia
AU - Boeger, Maria Regina Torres
AU - Sternberg, Leonel da Silveira Lobo O.Reilly
N1 - Funding Information:
The Brazilian Research Council (CNPq) provided financial support to this study ( 473015/2011-0 ). We would like to thank to the Coordination for the Improvement of Higher Education Personnel (CAPES-PDSE) for granted a doctoral fellowship to L.L. ( 013809/2013-0 ) and CNPq for providing fellowship to M.R.T.B. ( 309386/2007-1 ). We also would like to thank the colleagues from the Molecular Ecology and Evolutionary Parasitology Lab (LEMPE – UFPR) for their help in fieldwork.
Publisher Copyright:
© 2016 Elsevier B.V..
PY - 2016/8/1
Y1 - 2016/8/1
N2 - The study measured leaf gas exchange parameters and abundance of stable isotopes of C and N of three mangrove species (Rhizophora mangle L., Avicennia schaueriana Stapf & Leechm. ex Moldenke. and Laguncularia racemosa (L.) Gaertn) to investigate how photosynthetic capacity and water use efficiency characterize salt tolerance along an environmental gradient, in the Guaratuba Bay Estuary, Brazil, around 25°S. Along the estuary, parallel to the river, nine 50 m2 plots were marked: three plots at the fringe, three plots at the intermediary zone (around 150 m from the fringe), and three plots at the interior zone (around 350 m from the fringe), to represent the zonation pattern expressed by mangrove species. We used gas exchange parameters to calculate intrinsic water use efficiency (Amax/gs, WUEi). Long-term water use efficiency was calculated based on δ13C values, and δ15N values were related to source of N. Avicennia schaueriana showed the capacity to maintain high WUEi, even with high gs under higher salinities. The foliar δ13C of L. racemosa, was lower than the other species and negatively correlated to pore-water salinity. Rhizophora mangle gas exchange parameters did not correlate to the measured soil variables. Although the difference was not significant in R. mangle, δ 15N values indicate that fringe mangroves may use a marine source of N. How species respond to changes in pore-water salinity is expressed in both gas exchange parameters and isotopic signature through the floodplain gradient.
AB - The study measured leaf gas exchange parameters and abundance of stable isotopes of C and N of three mangrove species (Rhizophora mangle L., Avicennia schaueriana Stapf & Leechm. ex Moldenke. and Laguncularia racemosa (L.) Gaertn) to investigate how photosynthetic capacity and water use efficiency characterize salt tolerance along an environmental gradient, in the Guaratuba Bay Estuary, Brazil, around 25°S. Along the estuary, parallel to the river, nine 50 m2 plots were marked: three plots at the fringe, three plots at the intermediary zone (around 150 m from the fringe), and three plots at the interior zone (around 350 m from the fringe), to represent the zonation pattern expressed by mangrove species. We used gas exchange parameters to calculate intrinsic water use efficiency (Amax/gs, WUEi). Long-term water use efficiency was calculated based on δ13C values, and δ15N values were related to source of N. Avicennia schaueriana showed the capacity to maintain high WUEi, even with high gs under higher salinities. The foliar δ13C of L. racemosa, was lower than the other species and negatively correlated to pore-water salinity. Rhizophora mangle gas exchange parameters did not correlate to the measured soil variables. Although the difference was not significant in R. mangle, δ 15N values indicate that fringe mangroves may use a marine source of N. How species respond to changes in pore-water salinity is expressed in both gas exchange parameters and isotopic signature through the floodplain gradient.
KW - Photosynthetic rates
KW - Salinity tolerance
KW - Stable isotopes
KW - Water use efficiency
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U2 - 10.1016/j.aquabot.2016.06.001
DO - 10.1016/j.aquabot.2016.06.001
M3 - Article
AN - SCOPUS:84974588136
VL - 133
SP - 62
EP - 69
JO - Aquatic Botany
JF - Aquatic Botany
SN - 0304-3770
ER -