A new look at water transport regulation in plants

Martinez-Vilalta J., Poyatos R., Aguade D., Retana J., Mencuccini M. (2014) A new look at water transport regulation in plants. New Phytologist. : 0-0.
Enlace
Doi: 10.1111/nph.12912

Resumen:

Plant function requires effective mechanisms to regulate water transport at a variety of scales. Here, we develop a new theoretical framework describing plant responses to drying soil, based on the relationship between midday and predawn leaf water potentials. The intercept of the relationship (Λ) characterizes the maximum transpiration rate per unit of hydraulic transport capacity, whereas the slope (σ) measures the relative sensitivity of the transpiration rate and plant hydraulic conductance to declining water availability. This framework was applied to a newly compiled global database of leaf water potentials to estimate the values of Λ and σ for 102 plant species. Our results show that our characterization of drought responses is largely consistent within species, and that the parameters Λ and σ show meaningful associations with climate across species. Parameter σ was ≤1 in most species, indicating a tight coordination between the gas and liquid phases of water transport, in which canopy transpiration tended to decline faster than hydraulic conductance during drought, thus reducing the pressure drop through the plant. The quantitative framework presented here offers a new way of characterizing water transport regulation in plants that can be used to assess their vulnerability to drought under current and future climatic conditions. © 2014 New Phytologist Trust.

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Las poblaciones ibéricas de pino albar ante el cambio climático: con la muerte en los talones.

Martínez-Vilalta J, Aguadé D, Banqué M, Barba J, Curiel Yuste J, Galiano L, Garcia N, Gómez M, Heres; AM, López BC, Lloret F, Poyatos R, Retana J, Sus O, Vayreda J, Vilà-Cabrera A (2012) Las poblaciones ibéricas de pino albar ante el cambio climático: con la muerte en los talones. Ecosistemas 21: 15-21.

Las poblaciones ibéricas de pino albar ante el cambio climático: con la muerte en los talones.

Martínez-Vilalta J, Aguadé D, Banqué M, Barba J, Yuste JC, Galiano L, Garcia N, Gómez M, Hereş AM, López BC, Lloret F, Poyatos R, Retana J, Sus O, Vayreda J, Vilà-Cabrera A (2012) Las poblaciones ibéricas de pino albar ante el cambio climático: con la muerte en los talones. Revista Ecosistemas 21: 15–21.

Reassessing global change research priorities in mediterranean terrestrial ecosystems: How far have we come and where do we go from here?

Doblas-Miranda E., Martinez-Vilalta J., Lloret F., Alvarez A., Avila A., Bonet F.J., Brotons L., Castro J., Curiel Yuste J., Diaz M., Ferrandis P., Garcia-Hurtado E., Iriondo J.M., Keenan T.F., Latron J., Llusia J., Loepfe L., Mayol M., More G., Moya D., Penuelas J., Pons X., Poyatos R., Sardans J., Sus O., Vallejo V.R., Vayreda J., Retana J. (0) Reassessing global change research priorities in mediterranean terrestrial ecosystems: How far have we come and where do we go from here?. Global Ecology and Biogeography. 24: 25-43.
Enlace
Doi: 10.1111/geb.12224

Resumen:

Aim: Mediterranean terrestrial ecosystems serve as reference laboratories for the investigation of global change because of their transitional climate, the high spatiotemporal variability of their environmental conditions, a rich and unique biodiversity and a wide range of socio-economic conditions. As scientific development and environmental pressures increase, it is increasingly necessary to evaluate recent progress and to challenge research priorities in the face of global change. Location: Mediterranean terrestrial ecosystems. Methods: This article revisits the research priorities proposed in a 1998 assessment. Results: A new set of research priorities is proposed: (1) to establish the role of the landscape mosaic on fire-spread; (2) to further research the combined effect of different drivers on pest expansion; (3) to address the interaction between drivers of global change and recent forest management practices; (4) to obtain more realistic information on the impacts of global change and ecosystem services; (5) to assess forest mortality events associated with climatic extremes; (6) to focus global change research on identifying and managing vulnerable areas; (7) to use the functional traits concept to study resilience after disturbance; (8) to study the relationship between genotypic and phenotypic diversity as a source of forest resilience; (9) to understand the balance between C storage and water resources; (10) to analyse the interplay between landscape-scale processes and biodiversity conservation; (11) to refine models by including interactions between drivers and socio-economic contexts; (12) to understand forest-atmosphere feedbacks; (13) to represent key mechanisms linking plant hydraulics with landscape hydrology. Main conclusions: (1) The interactive nature of different global change drivers remains poorly understood. (2) There is a critical need for the rapid development of regional- and global-scale models that are more tightly connected with large-scale experiments, data networks and management practice. (3) More attention should be directed to drought-related forest decline and the current relevance of historical land use.

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