Isotopic signatures of stem water reveal differences in water sources accessed by mangrove tree species

Catherine E. Lovelock, Ruth Reef, Marilyn C. Ball

Research output: Contribution to journalArticleResearchpeer-review

15 Citations (Scopus)

Abstract

Mangrove trees are rooted in saline soils which can limit their growth. Access to alternative, less saline water sources may provide important water subsidies. We assessed the hydrogen and oxygen isotopic signatures of soil porewater, groundwater and atmospheric water sources (dew and rainfall) and tree stem water from three mangroves species over two sites that varied in elevation. Although stem water isotopic signatures were most similar to porewater, variation in isotopic values indicated trees also accessed alternative water sources, the degree to which varied over sites and among species. Rhizophora stylosa had lowest values of stable isotopes among the species indicating significant groundwater utilization. In a long-term fertilization experiment we found that growth of Ceriops australis and Lumnitzera racemosa was nitrogen limited, while growth of R. stylosa was nitrogen limited to a lesser extent, suggesting groundwater may also provide nutritional benefits for R. stylosa. The uptake of alternative water sources in addition to saline porewater may improve metabolic function, differentially altering the performance of different species and over sites.

Original languageEnglish
Pages (from-to)133-145
Number of pages13
JournalHydrobiologia
Volume803
DOIs
Publication statusPublished - 8 Mar 2017

Keywords

  • Ceriops australis
  • Groundwater
  • Lumnitzera racemosa
  • Rhizophora stylosa
  • δO
  • δH

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