%0 Journal Article
%T Variation in nitrogen use strategies and photosynthetic pathways among vascular epiphytes in the Brazilian Central Amazon
%A Mardegan
%A S.F.
%A Nardoto
%A G.B.
%A Higuchi
%A N.
%A Reinert
%A F.
%A Martinelli
%A L.A.
%J Brazilian Journal of Botany
%D 2011
%I Scientific Electronic Library Online
%R 10.1590/S0100-84042011000100003
%X the variation in nitrogen use strategies and photosynthetic pathways among vascular epiphyte families was addressed in a white-sand vegetation in the brazilian central amazon. foliar nitrogen and carbon concentrations and their isotopic composition (¦Ä15n and ¦Ä13c, respectively) were measured in epiphytes (araceae, bromeliaceae and orchidaceae) and their host trees. the host tree aldina heterophylla had higher foliar n concentration and lower c:n ratio (2.1 ¡À 0.06% and 23.6 ¡À 0.8) than its dwellers. tree foliar ¦Ä15n differed only from that of the orchids. comparing the epiphyte families, the aroids had the highest foliar n concentration and lowest c:n ratios (1.4 ¡À 0.1% and 34.9 ¡À 4.2, respectively). the orchids had more negative foliar ¦Ä15n values (-3.5 ¡À 0.2¡ë) than the aroids (-1.9 ¡À 0.7¡ë) and the bromeliads (-1.1 ¡À 0.6¡ë). within each family, aroid and orchid taxa differed in relation to foliar n concentrations and c:n ratios, whereas no internal variation was detected within bromeliads. the differences in foliar ¦Ä15n observed herein seem to be related to the differential reliance on the available n sources for epiphytes, as well as to the microhabitat quality within the canopy. in relation to epiphyte foliar ¦Ä13c, the majority of epiphytes use the water-conserving cam-pathway (¦Ä13c values around -17¡ë), commonly associated with plants that live under limited and intermittent water supply. only the aroids and one orchid taxon indicated the use of c3-pathway (¦Ä13c values around -30¡ë).
%K ¦Ä13c
%K ¦Ä15n
%K stable isotopes
%K white-sand vegetation.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0100-84042011000100003&lng=en&nrm=iso&tlng=en