Seasonal changes in water sources used by woody species in a tropical coastal dune forest
Our aim was to investigate the water sources used by woody species under contrasting water availability and the extent of water-sources-use differentiation among dominant woody species in a tropical coastal dune forest.
We sampled 15 woody species in a Brazilian restinga forest and, through Bayesian isotope mixing models, we estimated the proportion of water sources used. We tested whether water-sources-use was (i) different between contrasting water availability conditions; (ii) dependent on growth form, plant size or crown illumination; and (iii) influenced by stand density, evenness or biomass.
We found a seasonal variation in water-sources-use, but no vertical soil-water partitioning among woody species. In wetter periods, plants used mainly water from top-soil, as a shallow water table limited water uptake to top-soil layers recharged with rainwater. Contrastingly, during drier periods, with the absence of rain and a deeper water table, plants generally relied on deeper (50 cm) soil layers. Only under less-wet conditions, a greater evenness and density implied higher water-uptake depth heterogeneity among plants. However, changes in the main water-sources used by plants were neither evoked in more dense or diverse plots, nor induced by plant size.
Our study shows that restinga species have dynamic shifts in water-uptake depth caused by seasonal water availability changes, influenced by the combined effect of insufficient moisture at shallow soil layers and water-table lowering in drier periods. These temporal shifts are common among species, implying that restinga woody community has a homogeneous strategy of water-resources acquisition. This study enhances our understanding of the effects that water variations can have on water-resource use in restinga forests.
KeywordsWater-sources-use Coastal dune ecosystem Restinga forest Stable isotope mixing model Groundwater availability Soil-water partitioning
We thank to PPG - Ecologia, Instituto de Biologia, Universidade Estadual de Campinas, for the support given to Cristina Antunes in the development of this study. This research was funded by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) – Cristina Antunes PhD scholarship PROEX 0229083, and Fundação para a Ciência e a Tecnologia (FCT) – projects PTDC/AAC-CLI/118555/2010 and UID/BIA/00329/2013. The scientific project was co-supported by the Brazilian National Research Council/CNPq (PELD Process 403710/2012-0), by the British Natural Environment Research Council/NERC and by The State of São Paulo Research Foundation/FAPESP as part of the projects Functional Gradient, PELD/BIOTA and ECOFOR (Processes 2003/12595-7, 2012/51509-8 e 2012/51872-5, within the BIOTA/FAPESP Program - The Biodiversity Virtual Institute (www.biota.org.br); COTEC/IF 002.766/2013 and 010.631/2013 permits. Namely, we would like to thank: Yvonne Bakker, Luis Quimbayo Guzmán, Thaís Pimenta de Almeida and Marisol Rios for the help given during field surveys; Mauro Lo Cascio and Andreia Anjos for the laboratory work; João Barbosa for data base management; and Rodrigo Maia for isotopic analysis at SIIAF - Faculdade de Ciências, Universidade de Lisboa. The authors have no conflict of interest to declare.
- Assis MA, Prata EM, Pedroni F et al (2011) Florestas de Restinga e de Terras Baixas na Planície Costeira do sudeste do Brasil: vegetação e heterogeneidade ambiental. Biota Neotrop 11Google Scholar
- Bennett A, G Mcdowell N, Allen C, Anderson-Teixeira K (2015) Larger trees suffer most during drought in forests worldwideGoogle Scholar
- Dawson TE (1993) Water Sources of Plants as Determined from Xylem-Water Isotopic Composition: Perspectives on Plant Competition, Distribution, and Water RelationsGoogle Scholar
- de Oliveira VC (2011) Sobrevivência, morfo-anatomia, crescimento e assimilação de carbono de seis espécies arbóreas neotropicais submetidas à saturação hídrica do solo. Universidade Estadual de CampinasGoogle Scholar
- Ehleringer JR, Dawson TE (1992) Water uptake by plants: perspectives from stable isotope composition. Plant Cell Environ 15:1073–1082. https://doi.org/10.1111/j.1365-3040.1992.tb01657.x CrossRefGoogle Scholar
- Fan Y, Li H, Miguez-Macho G (2013) Global Patterns of Groundwater Table Depth. Science (80- ) 339:940 LP-943Google Scholar
- Fan Y, Miguez-Macho G, Jobbágy EG, et al (2017) Hydrologic regulation of plant rooting depth. Proc Natl Acad Sci 114:10572 LP-10577Google Scholar
- Gessler A, Nitschke R, de Mattos EA et al (2007) Comparison of the performance of three different ecophysiological life forms in a sandy coastal restinga ecosystem of SE-Brazil: a nodulated N2-fixing C3-shrub (Andira legalis (Vell.) Toledo), a CAM-shrub (Clusia hilariana Schltdl.) and a tap root C3-hemi. Trees 22:105. https://doi.org/10.1007/s00468-007-0174-7 CrossRefGoogle Scholar
- Keeling H, Phillips O (2007) A calibration method for the crown illumination index for assessing forest light environmentsGoogle Scholar
- McDowell N, Allen CD, Anderson-Teixeira K, et al (2018) Drivers and mechanisms of tree mortality in moist tropical forests. New Phytol n/a-n/a. https://doi.org/10.1111/nph.15027
- Pinheiro J, Bates D, DebRoy S, et al (2013) nlme: Linear and Nonlinear Mixed Effects ModelsGoogle Scholar
- Poorter L, Bongers F (2006) Leaf traits are good predictors of plant performance across 53 rain forest species. Ecology 87:1733–1743. https://doi.org/10.1890/0012-9658(2006)87[1733:LTAGPO]2.0.CO;2Google Scholar
- R Core Team (2015) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/
- Rodriguez-Iturbe I, D’Odorico P, Laio F et al (2007) Challenges in humid land ecohydrology: Interactions of water table and unsaturated zone with climate, soil, and vegetation. Water Resour Res 43. https://doi.org/10.1029/2007WR006073
- Rossatto DR, de Carvalho Ramos Silva L, Villalobos-Vega R et al (2012b) Depth of water uptake in woody plants relates to groundwater level and vegetation structure along a topographic gradient in a neotropical savanna. Environ Exp Bot 77:259–266. https://doi.org/10.1016/j.envexpbot.2011.11.025 CrossRefGoogle Scholar
- Santiago LS, De Guzman ME, Baraloto C, et al (2004) Coordination and trade-offs among hydraulic safety, efficiency and drought avoidance traits in Amazonian rainforest canopy tree species. New Phytol n/a-n/a. https://doi.org/10.1111/nph.15058
- Silva C (2015) Estoque e produção de raiz fina ao longo de um gradiente altitudinal de floresta atlântica na serra do mar. UNICAMP, São PauloGoogle Scholar
- Silvertown J, Dodd ME, Gowing DJG, Mountford JO (1999) Hydrologically defined niches reveal a basis for species richness in plant communities. Nature 400(61)Google Scholar
- Stock B, Jackson A, Ward E, Venkiteswaran J (2016) MixSIAR: v3.1.7Google Scholar
- Vieira SA, Alves LF, Aidar M et al (2008) Estimation of biomass and carbon stocks: the case of the Atlantic Forest. Biota Neotrop. 8(0)Google Scholar
- Wright SJ, Kitajima K, Kraft N, et al (2010) Functional traits and the growth-mortality trade-off in tropical treesGoogle Scholar
- Zea-Cabrera E, Iwasa Y, Levin S, Rodríguez-Iturbe I (2006) Tragedy of the commons in plant water use. Water Resour Res 42:n/a-n/a. https://doi.org/10.1029/2005WR004514