Removal of nutrient limitations by long-term fertilization decreases nocturnal water loss in savanna trees
Under certain environmental conditions, nocturnal transpiration can be relatively high in temperate and tropical woody species. We have previously shown that nocturnal sap flow accounts for up to 28% of total daily transpiration in woody species growing in a nutrient-poor Brazilian Cerrado ecosystem...
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2007
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0829318X_v27_n4_p551_Scholz http://hdl.handle.net/20.500.12110/paper_0829318X_v27_n4_p551_Scholz |
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paper:paper_0829318X_v27_n4_p551_Scholz2023-06-08T15:46:06Z Removal of nutrient limitations by long-term fertilization decreases nocturnal water loss in savanna trees Cerrado Leaf water potential Stomatal conductance Transpiration fertilizer application nitrogen nocturnal activity nutrient limitation nutrient uptake phosphorus physiological response sap flow savanna stomatal conductance transpiration tree water stress Brazil Cerrado South America Under certain environmental conditions, nocturnal transpiration can be relatively high in temperate and tropical woody species. We have previously shown that nocturnal sap flow accounts for up to 28% of total daily transpiration in woody species growing in a nutrient-poor Brazilian Cerrado ecosystem. In the present study, we assessed the effect of increased nutrient supply on nocturnal transpiration in three dominant Cerrado tree species to explore the hypothesis that, in nutrient-poor systems, continued transpiration at night may enhance delivery of nutrients to root-absorbing surfaces. We compared nocturnal transpiration of trees growing in unfertilized plots and plots to which nitrogen (N) and phosphorus (P) had been added twice yearly from 1998 to 2005. Three independent indicators of nocturnal transpiration were evaluated: sap flow in terminal branches, stomatal conductance (gs), and disequilibrium in water potential between covered and exposed leaves (ΔΨL). In the unfertilized trees, about 25% of the total daily sap flow occurred at night. Nocturnal sap flow was consistently lower in the N- and P-fertilized trees, significantly so in trees in the N treatment. Similarly, nocturnal gs was consistently lower in fertilized trees than in unfertilized trees where it sometimes reached values of 150 mmol m -2 s-1 by the end of the dark period. Predawn g s and the percentage of nocturnal sap flow were linearly related. Nocturnal ΔΨL was significantly greater in the unfertilized trees than in N- and P-fertilized trees. The absolute magnitude of ΔΨL increased linearly with the percentage of nocturnal sap flow. These results are consistent with the idea that enhancing nutrient uptake by allowing additional transpiration to occur at night when evaporative demand is lower may avoid excessive dehydration associated with increased stomatal opening during the day when evaporative demand is high. © 2006 Heron Publishing. 2007 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0829318X_v27_n4_p551_Scholz http://hdl.handle.net/20.500.12110/paper_0829318X_v27_n4_p551_Scholz |
| 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 Leaf water potential Stomatal conductance Transpiration fertilizer application nitrogen nocturnal activity nutrient limitation nutrient uptake phosphorus physiological response sap flow savanna stomatal conductance transpiration tree water stress Brazil Cerrado South America |
| spellingShingle |
Cerrado Leaf water potential Stomatal conductance Transpiration fertilizer application nitrogen nocturnal activity nutrient limitation nutrient uptake phosphorus physiological response sap flow savanna stomatal conductance transpiration tree water stress Brazil Cerrado South America Removal of nutrient limitations by long-term fertilization decreases nocturnal water loss in savanna trees |
| topic_facet |
Cerrado Leaf water potential Stomatal conductance Transpiration fertilizer application nitrogen nocturnal activity nutrient limitation nutrient uptake phosphorus physiological response sap flow savanna stomatal conductance transpiration tree water stress Brazil Cerrado South America |
| description |
Under certain environmental conditions, nocturnal transpiration can be relatively high in temperate and tropical woody species. We have previously shown that nocturnal sap flow accounts for up to 28% of total daily transpiration in woody species growing in a nutrient-poor Brazilian Cerrado ecosystem. In the present study, we assessed the effect of increased nutrient supply on nocturnal transpiration in three dominant Cerrado tree species to explore the hypothesis that, in nutrient-poor systems, continued transpiration at night may enhance delivery of nutrients to root-absorbing surfaces. We compared nocturnal transpiration of trees growing in unfertilized plots and plots to which nitrogen (N) and phosphorus (P) had been added twice yearly from 1998 to 2005. Three independent indicators of nocturnal transpiration were evaluated: sap flow in terminal branches, stomatal conductance (gs), and disequilibrium in water potential between covered and exposed leaves (ΔΨL). In the unfertilized trees, about 25% of the total daily sap flow occurred at night. Nocturnal sap flow was consistently lower in the N- and P-fertilized trees, significantly so in trees in the N treatment. Similarly, nocturnal gs was consistently lower in fertilized trees than in unfertilized trees where it sometimes reached values of 150 mmol m -2 s-1 by the end of the dark period. Predawn g s and the percentage of nocturnal sap flow were linearly related. Nocturnal ΔΨL was significantly greater in the unfertilized trees than in N- and P-fertilized trees. The absolute magnitude of ΔΨL increased linearly with the percentage of nocturnal sap flow. These results are consistent with the idea that enhancing nutrient uptake by allowing additional transpiration to occur at night when evaporative demand is lower may avoid excessive dehydration associated with increased stomatal opening during the day when evaporative demand is high. © 2006 Heron Publishing. |
| title |
Removal of nutrient limitations by long-term fertilization decreases nocturnal water loss in savanna trees |
| title_short |
Removal of nutrient limitations by long-term fertilization decreases nocturnal water loss in savanna trees |
| title_full |
Removal of nutrient limitations by long-term fertilization decreases nocturnal water loss in savanna trees |
| title_fullStr |
Removal of nutrient limitations by long-term fertilization decreases nocturnal water loss in savanna trees |
| title_full_unstemmed |
Removal of nutrient limitations by long-term fertilization decreases nocturnal water loss in savanna trees |
| title_sort |
removal of nutrient limitations by long-term fertilization decreases nocturnal water loss in savanna trees |
| publishDate |
2007 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0829318X_v27_n4_p551_Scholz http://hdl.handle.net/20.500.12110/paper_0829318X_v27_n4_p551_Scholz |
| _version_ |
1768541567239323648 |