Saharah Moon Chapotin
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Saharah Moon Chapotin has a total of 2 co-authors. Here are the top co-authors by number of shared publications:
Juvet H. Razanameharizaka
Laboratoire de Physiologie Végétale, URP70, Forêts et Biodiversité, B.P. 906, Université d’Antananarivo, Antananarivo (101), Madagascar
2 shared publicationsN. Michele Holbrook
Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA and
2 shared publications
Latest Publications
- Open Access
- 12 January 2006
- Published by Wiley in Plant, Cell & Environment
- Vol. 29 (6) , 1021-1032
Water relations of baobab trees (Adansonia spp. L.) during the rainy season: does stem water buffer daily water deficits?
Baobab trees are often cited in the literature as water‐storing trees, yet few studies have examined this assumption. We assessed the role of stored water in buffering daily water deficits in two species of baobabs (Adansonia rubrostipa Jum. and H. Perrier and Adansonia za Baill.) in a tropical dry forest in Madagascar. We found no lag in the daily onset of sap flow between the base and the crown of the tree. Some night‐time sap flow occurred, but this was more consistent with a pattern of seasonal stem water replenishment than with diurnal usage. Intrinsic capacitance of both leaf and stem tissue (0.07–0.08 and 1.1–1.43 MPa−1, respectively) was high, yet the amount of water that could be withdrawn before turgor loss was small because midday leaf and stem water potentials (WPs) were near the turgor‐loss points. Stomatal conductance was high in the daytime but then declined rapidly, suggesting an embolism‐avoidance strategy. Although the xylem of distal branches was relatively vulnerable to cavitation (P50: 1.1–1.7 MPa), tight stomatal control and minimum WPs near −1.0 MPa maintained native embolism levels at 30–65%. Stem morphology and anatomy restrict water movement between storage tissues and the conductive pathway, making stored‐water usage more appropriate to longer‐term water deficits than as a buffer against daily water deficits.
- 12 January 2006
- Published by Wiley in Plant, Cell & Environment
- Vol. 29 (6) , 1021-1032
Open AccessWater relations of baobab trees (Adansonia spp. L.) during the rainy season: does stem water buffer daily water deficits?
Baobab trees are often cited in the literature as water‐storing trees, yet few studies have examined this assumption. We assessed the role of stored water in buffering daily water deficits in two species of baobabs (Adansonia rubrostipa Jum. and H. Perrier and Adansonia za Baill.) in a tropical dry forest in Madagascar. We found no lag in the daily onset of sap flow between the base and the crown of the tree. Some night‐time sap flow occurred, but this was more consistent with a pattern of seasonal stem water replenishment than with diurnal usage. Intrinsic capacitance of both leaf and stem tissue (0.07–0.08 and 1.1–1.43 MPa−1, respectively) was high, yet the amount of water that could be withdrawn before turgor loss was small because midday leaf and stem water potentials (WPs) were near the turgor‐loss points. Stomatal conductance was high in the daytime but then declined rapidly, suggesting an embolism‐avoidance strategy. Although the xylem of distal branches was relatively vulnerable to cavitation (P50: 1.1–1.7 MPa), tight stomatal control and minimum WPs near −1.0 MPa maintained native embolism levels at 30–65%. Stem morphology and anatomy restrict water movement between storage tissues and the conductive pathway, making stored‐water usage more appropriate to longer‐term water deficits than as a buffer against daily water deficits.
- 10 January 2006
- Published by Wiley in New Phytologist
- Vol. 169 (3) , 549-559
Baobab trees (Adansonia) in Madagascar use stored water to flush new leaves but not to support stomatal opening before the rainy season
Baobab trees (Adansonia, Bombacaceae) are widely thought to store water in their stems for use when water availability is low. We tested this hypothesis by assessing the role of stored water during the dry season in three baobab species in Madagascar. In the dry season, leaves are present only during and after leaf flush. We quantified the relative contributions of stem and soil water during this period through measures of stem water content, sap flow and stomatal conductance. Rates of sap flow at the base of the trunk were near zero, indicating that leaf flushing was almost entirely dependent on stem water. Stem water content declined by up to 12% during this period, yet stomatal conductance and branch sap flow rates remained very low. Stem water reserves were used to support new leaf growth and cuticular transpiration, but not to support stomatal opening before the rainy season. Stomatal opening coincided with the onset of sap flow at the base of the trunk and occurred only after significant rainfall.
- 10 January 2006
- Published by Wiley in New Phytologist
- Vol. 169 (3) , 549-559
Baobab trees (Adansonia) in Madagascar use stored water to flush new leaves but not to support stomatal opening before the rainy season
Baobab trees (Adansonia, Bombacaceae) are widely thought to store water in their stems for use when water availability is low. We tested this hypothesis by assessing the role of stored water during the dry season in three baobab species in Madagascar. In the dry season, leaves are present only during and after leaf flush. We quantified the relative contributions of stem and soil water during this period through measures of stem water content, sap flow and stomatal conductance. Rates of sap flow at the base of the trunk were near zero, indicating that leaf flushing was almost entirely dependent on stem water. Stem water content declined by up to 12% during this period, yet stomatal conductance and branch sap flow rates remained very low. Stem water reserves were used to support new leaf growth and cuticular transpiration, but not to support stomatal opening before the rainy season. Stomatal opening coincided with the onset of sap flow at the base of the trunk and occurred only after significant rainfall.