Details

Autor(en) / Beteiligte

• Venturas, Martin D.
• Pratt, R. Brandon
• Jacobsen, Anna L.
• Castro, Viridiana
• Fickle, Jaycie C.
• Hacke, Uwe G.

Titel

Direct comparison of four methods to construct xylem vulnerability curves: Differences among techniques are linked to vessel network characteristics

Ist Teil von

• Plant, cell and environment, 2019-08, Vol.42 (8), p.2422-2436

Ort / Verlag

United States: Wiley Subscription Services, Inc

Erscheinungsjahr

2019

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• During periods of dehydration, water transport through xylem conduits can become blocked by embolism formation. Xylem embolism compromises water supply to leaves and may lead to losses in productivity or plant death. Vulnerability curves (VCs) characterize plant losses in conductivity as xylem pressures decrease. VCs are widely used to characterize and predict plant water use at different levels of water availability. Several methodologies for constructing VCs exist and sometimes produce different results for the same plant material. We directly compared four VC construction methods on stems of black cottonwood (Populus trichocarpa), a model tree species: dehydration, centrifuge, X‐ray–computed microtomography (microCT), and optical. MicroCT VC was the most resistant, dehydration and centrifuge VCs were intermediate, and optical VC was the most vulnerable. Differences among VCs were not associated with how cavitation was induced but were related to how losses in conductivity were evaluated: measured hydraulically (dehydration and centrifuge) versus evaluated from visual information (microCT and optical). Understanding how and why methods differ in estimating vulnerability to xylem embolism is important for advancing knowledge in plant ecophysiology, interpreting literature data, and using accurate VCs in water flux models for predicting plant responses to drought. We directly compared four methods for constructing xylem vulnerability to cavitation curves (VCs). Differences among VCs constructed with hydraulic and visual methods were associated with how losses in conductivity were evaluated, the spatial scale evaluated, and vessel network characteristics.