Evaluating the relative contributions of hydroperiod and soil fertility on growth of south Florida mangroves

Authors

Ken W. Krauss, National Wetlands Research Center, U.S. Geological Survey and Center for Ecology and Environmental Technology, University of Louisiana at LafayetteFollow
Thomas W. Doyle, National Wetlands Research Center, U.S. Geological SurveyFollow
Robert R. Twilley, Wetland Biogeochemistry Institute, Louisiana State UniversityFollow
Victor H. Rivera-Monroy, Wetland Biogeochemistry Institute, Louisiana State UniversityFollow
Jason K. Sullivan, National Wetlands Research Center, IAP World Services, Inc. and Regulatory and Ecological Services Group, John Chance Land Surveys, Inc.Follow

Abstract

Low and high water periods create contrasting challenges for trees inhabiting periodically flooded wetlands. Low to moderate flood durations and frequencies may bring nutrient subsidies, while greater hydroperiods can be energetically stressful because of oxygen deficiency. We tested the hypothesis that hydroperiod affects the growth of mangrove seedlings and saplings in a greenhouse experiment by varying flood duration while keeping salinity and soil fertility constant. We measured the growth of mangrove trees along a hydroperiod gradient over a two-year period by tracking fine-scale diameter increment. Greenhouse growth studies indicated that under a full range of annual flood durations (0–8760 h/year), hydroperiod alone exerted a significant influence on growth for one species, Laguncularia racemosa, when flooding was imposed for two growing seasons. Field evaluations, on the other hand, indicated that increased flood duration may provide nutrient subsidies for tree growth. Diameter growth was related curvilinearly to site hydroperiod, including flood duration and frequency, as well as to salinity and soil fertility. An analysis of soil physico-chemical parameters suggests that phosphorus fertility, which was also linked directly to hydroperiod, is likely to influence growth on south Florida mangrove sites. The physical removal of phosphorus by greater flood frequencies from upland sources and/or addition of phosphorus from tidal flooding balanced against increased soil aeration and reduced water deficits may be an extremely important growth determinant for south Florida mangroves.

Comments

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Recommended Citation

Krauss, K.W., T.W. Doyle, R.R. Twilley, V.H. Rivera-Monroy, J.K. Sullivan. 2006. Evaluating the relative contributions of hydroperiod and soil fertility on growth of south Florida mangroves. Hydrobiologia 569(1): 311-324.