Velocity of change in vegetation productivity over northern high latitudes

Huang, M., Piao, S., Janssens, I.A., Zhu, Z., Wang, T., Wu, D., Ciais, P., Myneni, R.B., Peaucelle, M., Peng, S., Yang, H., Peñuelas, J. (2017) Velocity of change in vegetation productivity over northern high latitudes. Nature Ecology and Evolution. 1: 1649-1654.
Link
Doi: 10.1038/s41559-017-0328-y

Abstract:

Impacts of global change on Mediterranean forests and their services

Peñuelas, J., Sardans, J., Filella, I., Estiarte, M., Llusià, J., Ogaya, R., Carnicer, J., Bartrons, M., Rivas-Ubach, A., Grau, O., Peguero, G., Margalef, O., Pla-Rabés, S., Stefanescu, C., Asensio, D., Preece, C., Liu, L., Verger, A., Barbeta, A., Achotegui-Castells, A., Gargallo-Garriga, A., Sperlich, D., Farré-Armengol, G., Fernández-Martínez, M., Liu, D., Zhang, C., Urbina, I., Camino-Serrano, M., Vives-Ingla, M., Stocker, B.D., Balzarolo, M., Guerrieri, R., Peaucelle, M., Marañón-Jiménez, S., Bórnez-Mejías, K., Mu, Z., Descals, A., Castellanos, A., Terradas, J. (2017) Impacts of global change on Mediterranean forests and their services. Forests. 8: 0-0.
Link
Doi: 10.3390/f8120463

Abstract:

Three times greater weight of daytime than of night-time temperature on leaf unfolding phenology in temperate trees

Fu Y.H., Liu Y., De Boeck H.J., Menzel A., Nijs I., Peaucelle M., Peñuelas J., Piao S., Janssens I.A. (2016) Three times greater weight of daytime than of night-time temperature on leaf unfolding phenology in temperate trees. New Phytologist. : 0-0.
Link
Doi: 10.1111/nph.14073

Abstract:

The phenology of spring leaf unfolding plays a key role in the structure and functioning of ecosystems. The classical concept of heat requirement (growing degree days) for leaf unfolding was developed hundreds of years ago, but this model does not include the recently reported greater importance of daytime than night-time temperature. A manipulative experiment on daytime vs night-time warming with saplings of three species of temperate deciduous trees was conducted and a Bayesian method was applied to explore the different effects of daytime and night-time temperatures on spring phenology. We found that both daytime and night-time warming significantly advanced leaf unfolding, but the sensitivities to increased daytime and night-time temperatures differed significantly. Trees were most sensitive to daytime warming (7.4 ± 0.9, 4.8 ± 0.3 and 4.8 ± 0.2 d advancement per degree Celsius warming (d °C-1) for birch, oak and beech, respectively) and least sensitive to night-time warming (5.5 ± 0.9, 3.3 ± 0.3 and 2.1 ± 0.9 d °C-1). Interestingly, a Bayesian analysis found that the impact of daytime temperature on leaf unfolding was approximately three times higher than that of night-time temperatures. Night-time global temperature is increasing faster than daytime temperature, so model projections of future spring phenology should incorporate the effects of these different temperatures. © 2016 New Phytologist Trust.

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Long-term linear trends mask phenological shifts

Fu, Y.H., Piao, S., Ciais, P., Huang, M., Menzel, A., Peaucelle, M., Peng, S., Song, Y., Vitasse, Y., Zeng, Z., Zhao, H., Zhou, G., Peñuelas, J., Janssens, I.A. (2016) Long-term linear trends mask phenological shifts. International Journal of Biometeorology. : 1-3.
Link
Doi: 10.1007/s00484-016-1253-5

Abstract:

A new approach to optimal discretization of plant functional types in a process-based ecosystem model with forest management: A case study for temperate conifers

Peaucelle, M., Bellassen, V., Ciais, P., Peñuelas, J., Viovy, N. (2016) A new approach to optimal discretization of plant functional types in a process-based ecosystem model with forest management: A case study for temperate conifers. Global Ecology and Biogeography. : 0-0.
Link
Doi: 10.1111/geb.12557

Abstract:

Declining global warming effects on the phenology of spring leaf unfolding

Fu Y.H., Zhao H., Piao S., Peaucelle M., Peng S., Zhou G., Ciais P., Huang M., Menzel A., Peñuelas J., Song Y., Vitasse Y., Zeng Z., Janssens I.A. (2015) Declining global warming effects on the phenology of spring leaf unfolding. Nature. 526: 104-107.
Link
Doi: 10.1038/nature15402

Abstract:

Earlier spring leaf unfolding is a frequently observed response of plants to climate warming. Many deciduous tree species require chilling for dormancy release, and warming-related reductions in chilling may counteract the advance of leaf unfolding in response to warming. Empirical evidence for this, however, is limited to saplings or twigs in climate-controlled chambers. Using long-term in situ observations of leaf unfolding for seven dominant European tree species at 1,245 sites, here we show that the apparent response of leaf unfolding to climate warming (S T, expressed in days advance of leaf unfolding per °C warming) has significantly decreased from 1980 to 2013 in all monitored tree species. Averaged across all species and sites, S T decreased by 40% from 4.0 ± 1.8 days °C-1 during 1980-1994 to 2.3 ± 1.6 days °C-1 during 1999-2013. The declining S T was also simulated by chilling-based phenology models, albeit with a weaker decline (24-30%) than observed in situ. The reduction in S T is likely to be partly attributable to reduced chilling. Nonetheless, other mechanisms may also have a role, such as 'photoperiod limitation' mechanisms that may become ultimately limiting when leaf unfolding dates occur too early in the season. Our results provide empirical evidence for a declining S T, but also suggest that the predicted strong winter warming in the future may further reduce S T and therefore result in a slowdown in the advance of tree spring phenology. © 2015 Macmillan Publishers Limited. All rights reserved.

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