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Summary Grasses are exceptionally productive, yet their hydraulic adaptation is paradoxical. Among C3grasses, a high photosynthetic rate (Aarea) may depend on higher vein density (Dv) and hydraulic conductance (Kleaf). However, the higherDvof C4grasses suggests a hydraulic surplus, given their reduced need for highKleafresulting from lower stomatal conductance (gs).Combining hydraulic and photosynthetic physiological data for diverse common garden C3and C4species with data for 332 species from the published literature, and mechanistic modeling, we validated a framework for linkages of photosynthesis with hydraulic transport, anatomy, and adaptation to aridity.C3and C4grasses had similarKleafin our common garden, but C4grasses had higherKleafthan C3species in our meta‐analysis. Variation inKleafdepended on outside‐xylem pathways. C4grasses have highKleaf : gs, which modeling shows is essential to achieve their photosynthetic advantage.Across C3grasses, higherAareawas associated with higherKleaf, and adaptation to aridity, whereas for C4species, adaptation to aridity was associated with higherKleaf : gs. These associations are consistent with adaptation for stress avoidance.Hydraulic traits are a critical element of evolutionary and ecological success in C3and C4grasses and are crucial avenues for crop design and ecological forecasting.
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Barrier layer design reduces top electrode ion migration in perovskite solar cells
We report on an examination of mobile ion concentration (N0) in perovskite solar cells (PSCs) as a function of temperature and device architecture.
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- PAR ID:
- 10592223
- Publisher / Repository:
- EES Solar
- Date Published:
- Journal Name:
- EES Solar
- ISSN:
- 3033-4063
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Summary Leaf dark respiration (Rd) acclimates to environmental changes. However, the magnitude, controls and time scales of acclimation remain unclear and are inconsistently treated in ecosystem models.We hypothesized thatRdand Rubisco carboxylation capacity (Vcmax) at 25°C (Rd,25,Vcmax,25) are coordinated so thatRd,25variations supportVcmax,25at a level allowing full light use, withVcmax,25reflecting daytime conditions (for photosynthesis), andRd,25/Vcmax,25reflecting night‐time conditions (for starch degradation and sucrose export). We tested this hypothesis temporally using a 5‐yr warming experiment, and spatially using an extensive field‐measurement data set. We compared the results to three published alternatives:Rd,25declines linearly with daily average prior temperature;Rdat average prior night temperatures tends towards a constant value; andRd,25/Vcmax,25is constant.Our hypothesis accounted for more variation in observedRd,25over time (R2 = 0.74) and space (R2 = 0.68) than the alternatives. Night‐time temperature dominated the seasonal time‐course ofRd, with an apparent response time scale ofc.2 wk.Vcmaxdominated the spatial patterns.Our acclimation hypothesis results in a smaller increase in globalRdin response to rising CO2and warming than is projected by the two of three alternative hypotheses, and by current models.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1039/D5EL00051C
