Partitioning of soil water among tree species in a Brazilian Cerrado ecosystem
Source water used by woody perennials in a Brazilian savanna (Cerrado) was determined by comparing the stable hydrogen isotope composition (δD) of xylem sap and soil water at different depths during two consecutive dry seasons (1995 and 1996). Plant water status and rates of water use were also dete...
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Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0829318X_v19_n11_p717_Jackson http://hdl.handle.net/20.500.12110/paper_0829318X_v19_n11_p717_Jackson |
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paper:paper_0829318X_v19_n11_p717_Jackson2023-06-08T15:46:04Z Partitioning of soil water among tree species in a Brazilian Cerrado ecosystem Goldstein, Guillermo Hernan Igler, Erica Causin, Humberto Fabio Deciduous Deuterium Evergreen Hydraulic lift Neotropical savanna Resource partitioning Roots Stable hydrogen isotope composition cerrado niche partitioning soil water tree water use Brazil Source water used by woody perennials in a Brazilian savanna (Cerrado) was determined by comparing the stable hydrogen isotope composition (δD) of xylem sap and soil water at different depths during two consecutive dry seasons (1995 and 1996). Plant water status and rates of water use were also determined and compared with xylem water δD values. Overall, soil water δD decreased with increasing depth in the soil profile. Mean δD values were -35‰ for the upper 170 cm of soil and -55‰ between 230 and 400 cm depth at the end of the 1995 dry season. Soil water content increased with depth, from 18% near the surface to about 28% at 400 cm. A similar pattern of decreasing soil water δD with increasing depth was observed at the end of the 1996 dry season. Patterns consistent with hydraulic lift were observed in soil profiles sampled in 1995 and 1997. Concurrent analyses of xylem and soil water δD values indicated a distinct partitioning of water resources among 10 representative woody species (five deciduous and five evergreen). Among these species, four evergreen and one deciduous species acquired water primarily in the upper soil layers (above 200 cm), whereas three deciduous and one evergreen species tapped deep sources of soil water (below 200 cm). One deciduous species exhibited intermediate behavior. Total daily sap flow was negatively correlated with xylem sap δD values indicating that species with higher rates of water use during the dry season tended to rely on deeper soil water sources. Among evergreen species, minimum leaf water potentials were also negatively correlated with xylem water δD values, suggesting that access to more readily available water at greater depth permitted maintenance of a more favorable plant water status. No significant relationship between xylem water δD and plant size was observed in two evergreen species, suggesting a strong selective pressure for small plants to rapidly develop a deep root system. The degree of variation in soil water partitioning, leaf phenology and leaf longevity was consistent with the high diversity of woody species in the Cerrado. Fil:Goldstein, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Igler, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Causin, F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1999 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0829318X_v19_n11_p717_Jackson http://hdl.handle.net/20.500.12110/paper_0829318X_v19_n11_p717_Jackson |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
Deciduous Deuterium Evergreen Hydraulic lift Neotropical savanna Resource partitioning Roots Stable hydrogen isotope composition cerrado niche partitioning soil water tree water use Brazil |
spellingShingle |
Deciduous Deuterium Evergreen Hydraulic lift Neotropical savanna Resource partitioning Roots Stable hydrogen isotope composition cerrado niche partitioning soil water tree water use Brazil Goldstein, Guillermo Hernan Igler, Erica Causin, Humberto Fabio Partitioning of soil water among tree species in a Brazilian Cerrado ecosystem |
topic_facet |
Deciduous Deuterium Evergreen Hydraulic lift Neotropical savanna Resource partitioning Roots Stable hydrogen isotope composition cerrado niche partitioning soil water tree water use Brazil |
description |
Source water used by woody perennials in a Brazilian savanna (Cerrado) was determined by comparing the stable hydrogen isotope composition (δD) of xylem sap and soil water at different depths during two consecutive dry seasons (1995 and 1996). Plant water status and rates of water use were also determined and compared with xylem water δD values. Overall, soil water δD decreased with increasing depth in the soil profile. Mean δD values were -35‰ for the upper 170 cm of soil and -55‰ between 230 and 400 cm depth at the end of the 1995 dry season. Soil water content increased with depth, from 18% near the surface to about 28% at 400 cm. A similar pattern of decreasing soil water δD with increasing depth was observed at the end of the 1996 dry season. Patterns consistent with hydraulic lift were observed in soil profiles sampled in 1995 and 1997. Concurrent analyses of xylem and soil water δD values indicated a distinct partitioning of water resources among 10 representative woody species (five deciduous and five evergreen). Among these species, four evergreen and one deciduous species acquired water primarily in the upper soil layers (above 200 cm), whereas three deciduous and one evergreen species tapped deep sources of soil water (below 200 cm). One deciduous species exhibited intermediate behavior. Total daily sap flow was negatively correlated with xylem sap δD values indicating that species with higher rates of water use during the dry season tended to rely on deeper soil water sources. Among evergreen species, minimum leaf water potentials were also negatively correlated with xylem water δD values, suggesting that access to more readily available water at greater depth permitted maintenance of a more favorable plant water status. No significant relationship between xylem water δD and plant size was observed in two evergreen species, suggesting a strong selective pressure for small plants to rapidly develop a deep root system. The degree of variation in soil water partitioning, leaf phenology and leaf longevity was consistent with the high diversity of woody species in the Cerrado. |
author |
Goldstein, Guillermo Hernan Igler, Erica Causin, Humberto Fabio |
author_facet |
Goldstein, Guillermo Hernan Igler, Erica Causin, Humberto Fabio |
author_sort |
Goldstein, Guillermo Hernan |
title |
Partitioning of soil water among tree species in a Brazilian Cerrado ecosystem |
title_short |
Partitioning of soil water among tree species in a Brazilian Cerrado ecosystem |
title_full |
Partitioning of soil water among tree species in a Brazilian Cerrado ecosystem |
title_fullStr |
Partitioning of soil water among tree species in a Brazilian Cerrado ecosystem |
title_full_unstemmed |
Partitioning of soil water among tree species in a Brazilian Cerrado ecosystem |
title_sort |
partitioning of soil water among tree species in a brazilian cerrado ecosystem |
publishDate |
1999 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0829318X_v19_n11_p717_Jackson http://hdl.handle.net/20.500.12110/paper_0829318X_v19_n11_p717_Jackson |
work_keys_str_mv |
AT goldsteinguillermohernan partitioningofsoilwateramongtreespeciesinabraziliancerradoecosystem AT iglererica partitioningofsoilwateramongtreespeciesinabraziliancerradoecosystem AT causinhumbertofabio partitioningofsoilwateramongtreespeciesinabraziliancerradoecosystem |
_version_ |
1768541617055072256 |