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Bioavailability and sources of DOC and DON in macrophyte stands of a tropical coastal lake

Stepanauskas, R; Farjalla, V F; Tranvik, L J; Svensson, J M; Esteves, F A and Granéli, Wilhelm LU (2000) In Hydrobiologia 436(1-3). p.241-248
Abstract
Dissolved organic carbon (DOC) and nitrogen (DON) derived from aquatic and terrestrial vascular plants provide a major energy and nutrient source for freshwater and coastal marine biota. The bioavailability of this material may to a large extent depend on plant species. In this study, we have compared the bioavailability of DOC and DON sampled in two distinct stands of Typha domingensis and Eleocharis mutata in a coastal tropical lake and in the adjacent ocean in the state of Rio de Janeiro, Brazil. Bioavailability of organic matter was assessed by regrowth bioassays using natural bacterial inocula. Nutrients were added to achieve carbon or nitrogen limitation. At all sampling sites, DON comprised over 95% of the total bioavailable... (More)
Dissolved organic carbon (DOC) and nitrogen (DON) derived from aquatic and terrestrial vascular plants provide a major energy and nutrient source for freshwater and coastal marine biota. The bioavailability of this material may to a large extent depend on plant species. In this study, we have compared the bioavailability of DOC and DON sampled in two distinct stands of Typha domingensis and Eleocharis mutata in a coastal tropical lake and in the adjacent ocean in the state of Rio de Janeiro, Brazil. Bioavailability of organic matter was assessed by regrowth bioassays using natural bacterial inocula. Nutrients were added to achieve carbon or nitrogen limitation. At all sampling sites, DON comprised over 95% of the total bioavailable nitrogen, suggesting its dominant role as a nitrogen source. The bioavailability of lacustrine DON (22% in the Typha stand and 34% in the Eleocharis stand) exceeded the bioavailability of DOC (8 and 10%, respectively) and exhibited a larger difference between the stands. H-3-leucine incorporation studies showed that lake bacterioplankton had a well balanced supply of C, N and P. Therefore, an accumulation of labile DON due to an excess nitrogen supply is not probable. We propose that a substantial part of the lake DON was newly formed within the macrophyte stands, while DOC was predominantly of terrestrial origin and more diagenetically changed. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Hydrobiologia
volume
436
issue
1-3
pages
241 - 248
publisher
Springer
external identifiers
  • scopus:0034290456
ISSN
0018-8158
DOI
10.1023/A:1026537905947
language
English
LU publication?
yes
id
d5d7caaf-cadc-4fc0-ac29-2afb8a3b459d (old id 146692)
date added to LUP
2007-06-29 07:54:29
date last changed
2017-01-01 05:16:42
@article{d5d7caaf-cadc-4fc0-ac29-2afb8a3b459d,
  abstract     = {Dissolved organic carbon (DOC) and nitrogen (DON) derived from aquatic and terrestrial vascular plants provide a major energy and nutrient source for freshwater and coastal marine biota. The bioavailability of this material may to a large extent depend on plant species. In this study, we have compared the bioavailability of DOC and DON sampled in two distinct stands of Typha domingensis and Eleocharis mutata in a coastal tropical lake and in the adjacent ocean in the state of Rio de Janeiro, Brazil. Bioavailability of organic matter was assessed by regrowth bioassays using natural bacterial inocula. Nutrients were added to achieve carbon or nitrogen limitation. At all sampling sites, DON comprised over 95% of the total bioavailable nitrogen, suggesting its dominant role as a nitrogen source. The bioavailability of lacustrine DON (22% in the Typha stand and 34% in the Eleocharis stand) exceeded the bioavailability of DOC (8 and 10%, respectively) and exhibited a larger difference between the stands. H-3-leucine incorporation studies showed that lake bacterioplankton had a well balanced supply of C, N and P. Therefore, an accumulation of labile DON due to an excess nitrogen supply is not probable. We propose that a substantial part of the lake DON was newly formed within the macrophyte stands, while DOC was predominantly of terrestrial origin and more diagenetically changed.},
  author       = {Stepanauskas, R and Farjalla, V F and Tranvik, L J and Svensson, J M and Esteves, F A and Granéli, Wilhelm},
  issn         = {0018-8158},
  language     = {eng},
  number       = {1-3},
  pages        = {241--248},
  publisher    = {Springer},
  series       = {Hydrobiologia},
  title        = {Bioavailability and sources of DOC and DON in macrophyte stands of a tropical coastal lake},
  url          = {http://dx.doi.org/10.1023/A:1026537905947},
  volume       = {436},
  year         = {2000},
}