Functional convergence in hydraulic architecture and water relations of tropical savanna trees: From leaf to whole plant
Functional convergence in hydraulic architecture and water relations, and potential trade-offs in resource allocation were investigated in six dominant neotropical savanna tree species from central Brazil during the peak of the dry season. Common relationships between wood density and several aspect...
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2004
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0829318X_v24_n8_p891_Bucci http://hdl.handle.net/20.500.12110/paper_0829318X_v24_n8_p891_Bucci |
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paper:paper_0829318X_v24_n8_p891_Bucci2023-06-08T15:46:05Z Functional convergence in hydraulic architecture and water relations of tropical savanna trees: From leaf to whole plant Cerrado Hydraulic conductivity Sap flow Soil water potential Water transport Wood density adaptation cerrado plant water relations resource allocation sap flow trade-off Functional convergence in hydraulic architecture and water relations, and potential trade-offs in resource allocation were investigated in six dominant neotropical savanna tree species from central Brazil during the peak of the dry season. Common relationships between wood density and several aspects of plant water relations and hydraulic architecture were observed. All species and individuals shared the same negative exponential relationship between sapwood saturated water content and wood density. Wood density was a good predictor of minimum (midday) leaf water potential and total daily transpiration, both of which decreased linearly with increasing wood density for all individuals and species. With respect to hydraulic architecture, specific and leaf-specific hydraulic conductivity decreased and the leaf:sapwood area ratio increased more than 5-fold as wood density increased from 0.37 to 0.71 g cm-3 for all individuals and species. Wood density was also a good predictor of the temporal dynamics of water flow in stems, with the time of onset of sap flow in the morning and the maximum sap flow tending to occur progressively earlier in the day as wood density increased. Leaf properties associated with wood density included stomatal conductance, specific leaf area, and osmotic potential at the turgor loss point, which decreased linearly with increasing wood density. Wood density increased linearly with decreasing bulk soil water potential experienced by individual plants during the dry season, suggesting that wood density was greatest in individuals with mostly shallow roots, and therefore limited access to more abundant soil water at greater depths. Despite their taxonomic diversity and large intrapopulation differences in architectural traits, the six co-occurring species and their individuals shared similar functional relationships between all pairs of variables studied. Thus, rather than differing intrinsically in physiological responsiveness, the species and the individuals appeared to have distinct operating ranges along common physiological response curves dictated by plant architectural and structural features. The patterns of water uptake and access to soil water during the dry season appeared to be the main determinant of wood density, which constrained evolutionary options related to plant water economy and hydraulic architecture, leading to functional convergence in the neotropical savanna trees studied. 2004 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0829318X_v24_n8_p891_Bucci http://hdl.handle.net/20.500.12110/paper_0829318X_v24_n8_p891_Bucci |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Cerrado Hydraulic conductivity Sap flow Soil water potential Water transport Wood density adaptation cerrado plant water relations resource allocation sap flow trade-off |
| spellingShingle |
Cerrado Hydraulic conductivity Sap flow Soil water potential Water transport Wood density adaptation cerrado plant water relations resource allocation sap flow trade-off Functional convergence in hydraulic architecture and water relations of tropical savanna trees: From leaf to whole plant |
| topic_facet |
Cerrado Hydraulic conductivity Sap flow Soil water potential Water transport Wood density adaptation cerrado plant water relations resource allocation sap flow trade-off |
| description |
Functional convergence in hydraulic architecture and water relations, and potential trade-offs in resource allocation were investigated in six dominant neotropical savanna tree species from central Brazil during the peak of the dry season. Common relationships between wood density and several aspects of plant water relations and hydraulic architecture were observed. All species and individuals shared the same negative exponential relationship between sapwood saturated water content and wood density. Wood density was a good predictor of minimum (midday) leaf water potential and total daily transpiration, both of which decreased linearly with increasing wood density for all individuals and species. With respect to hydraulic architecture, specific and leaf-specific hydraulic conductivity decreased and the leaf:sapwood area ratio increased more than 5-fold as wood density increased from 0.37 to 0.71 g cm-3 for all individuals and species. Wood density was also a good predictor of the temporal dynamics of water flow in stems, with the time of onset of sap flow in the morning and the maximum sap flow tending to occur progressively earlier in the day as wood density increased. Leaf properties associated with wood density included stomatal conductance, specific leaf area, and osmotic potential at the turgor loss point, which decreased linearly with increasing wood density. Wood density increased linearly with decreasing bulk soil water potential experienced by individual plants during the dry season, suggesting that wood density was greatest in individuals with mostly shallow roots, and therefore limited access to more abundant soil water at greater depths. Despite their taxonomic diversity and large intrapopulation differences in architectural traits, the six co-occurring species and their individuals shared similar functional relationships between all pairs of variables studied. Thus, rather than differing intrinsically in physiological responsiveness, the species and the individuals appeared to have distinct operating ranges along common physiological response curves dictated by plant architectural and structural features. The patterns of water uptake and access to soil water during the dry season appeared to be the main determinant of wood density, which constrained evolutionary options related to plant water economy and hydraulic architecture, leading to functional convergence in the neotropical savanna trees studied. |
| title |
Functional convergence in hydraulic architecture and water relations of tropical savanna trees: From leaf to whole plant |
| title_short |
Functional convergence in hydraulic architecture and water relations of tropical savanna trees: From leaf to whole plant |
| title_full |
Functional convergence in hydraulic architecture and water relations of tropical savanna trees: From leaf to whole plant |
| title_fullStr |
Functional convergence in hydraulic architecture and water relations of tropical savanna trees: From leaf to whole plant |
| title_full_unstemmed |
Functional convergence in hydraulic architecture and water relations of tropical savanna trees: From leaf to whole plant |
| title_sort |
functional convergence in hydraulic architecture and water relations of tropical savanna trees: from leaf to whole plant |
| publishDate |
2004 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0829318X_v24_n8_p891_Bucci http://hdl.handle.net/20.500.12110/paper_0829318X_v24_n8_p891_Bucci |
| _version_ |
1768545790916034560 |