32 results on '"Robson, T. M."'
Search Results
2. Interactive effects of changes in UV radiation and climate on terrestrial ecosystems, biogeochemical cycles, and feedbacks to the climate system
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Barnes, P. W., Robson, T. M., Zepp, R. G., Bornman, J. F., Jansen, M. A. K., Ossola, R., Wang, Q.-W., Robinson, S. A., Foereid, B., Klekociuk, A. R., Martinez-Abaigar, J., Hou, W.-C., Mackenzie, R., and Paul, N. D.
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- 2023
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3. Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2021
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Barnes, P. W., Robson, T. M., Neale, P. J., Williamson, C. E., Zepp, R. G., Madronich, S., Wilson, S. R., Andrady, A. L., Heikkilä, A. M., Bernhard, G. H., Bais, A. F., Neale, R. E., Bornman, J. F., Jansen, M. A. K., Klekociuk, A. R., Martinez-Abaigar, J., Robinson, S. A., Wang, Q.-W., Banaszak, A. T., Häder, D.-P., Hylander, S., Rose, K. C., Wängberg, S.-Å., Foereid, B., Hou, W.-C., Ossola, R., Paul, N. D., Ukpebor, J. E., Andersen, M. P. S., Longstreth, J., Schikowski, T., Solomon, K. R., Sulzberger, B., Bruckman, L. S., Pandey, K. K., White, C. C., Zhu, L., Zhu, M., Aucamp, P. J., Liley, J. B., McKenzie, R. L., Berwick, M., Byrne, S. N., Hollestein, L. M., Lucas, R. M., Olsen, C. M., Rhodes, L. E., Yazar, S., and Young, A. R.
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- 2022
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4. Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2020
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Neale, R. E., Barnes, P. W., Robson, T. M., Neale, P. J., Williamson, C. E., Zepp, R. G., Wilson, S. R., Madronich, S., Andrady, A. L., Heikkilä, A. M., Bernhard, G. H., Bais, A. F., Aucamp, P. J., Banaszak, A. T., Bornman, J. F., Bruckman, L. S., Byrne, S. N., Foereid, B., Häder, D.-P., Hollestein, L. M., Hou, W.-C., Hylander, S., Jansen, M. A. K., Klekociuk, A. R., Liley, J. B., Longstreth, J., Lucas, R. M., Martinez-Abaigar, J., McNeill, K., Olsen, C. M., Pandey, K. K., Rhodes, L. E., Robinson, S. A., Rose, K. C., Schikowski, T., Solomon, K. R., Sulzberger, B., Ukpebor, J. E., Wang, Q.-W., Wängberg, S.-Å., White, C. C., Yazar, S., Young, A. R., Young, P. J., Zhu, L., and Zhu, M.
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- 2021
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5. Environmental effects of stratospheric ozone depletion, UV radiation and interactions with climate change: UNEP Environmental Effects Assessment Panel, update 2019
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Bernhard, G. H., Neale, R. E., Barnes, P. W., Neale, P. J., Zepp, R. G., Wilson, S. R., Andrady, A. L., Bais, A. F., McKenzie, R. L., Aucamp, P. J., Young, P. J., Liley, J. B., Lucas, R. M., Yazar, S., Rhodes, L. E., Byrne, S. N., Hollestein, L. M., Olsen, C. M., Young, A. R., Robson, T. M., Bornman, J. F., Jansen, M. A. K., Robinson, S. A., Ballaré, C. L., Williamson, C. E., Rose, K. C., Banaszak, A. T., Häder, D. -P., Hylander, S., Wängberg, S. -Å., Austin, A. T., Hou, W. -C., Paul, N. D., Madronich, S., Sulzberger, B., Solomon, K. R., Li, H., Schikowski, T., Longstreth, J., Pandey, K. K., Heikkilä, A. M., and White, C. C.
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- 2020
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6. Environmental effects of ozone depletion, UV radiation and interactions with climate change: UNEP Environmental Effects Assessment Panel, update 2017
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Bais, A. F., Lucas, R. M., Bornman, J. F., Williamson, C. E., Sulzberger, B., Austin, A. T., Wilson, S. R., Andrady, A. L., Bernhard, G., McKenzie, R. L., Aucamp, P. J., Madronich, S., Neale, R. E., Yazar, S., Young, A. R., de Gruijl, F. R., Norval, M., Takizawa, Y., Barnes, P. W., Robson, T. M., Robinson, S. A., Bailaré, C. L., Flint, S. D., Neale, P. J., Hylander, S., Rose, K. C., Wängberg, S. -Å., Hader, D. -P., Worrest, R. C., Zepp, R. G., Paul, N. D., Cory, R. M., Solomon, K. R., Longstreth, J., Pandey, K. K., Redhwi, H. H., Torikai, A., and Heikkilä, A. M.
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- 2018
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7. UV-B-induced morphological changes - an enigma.
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Jansen, M. A. K., primary, Klem, K., additional, Robson, T. M., additional, and Urban, O., additional
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- 2017
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8. Plant responses to fluctuating UV environments.
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Barnes, P. W., primary, Robson, T. M., additional, Tobler, M. A., additional, Bottger, I. N., additional, and Flint, S. D., additional
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- 2017
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9. Seedlings from marginal and core populations of European beech (Fagus sylvatica L.) respond differently to imposed drought and shade
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University of Helsinki, Helsinki University Hospital, Bavarian Office for Forestry Seed and Plant Breeding, Southern Swedish Forest Research Centre, Ministerio de Educación y Ciencia (España), Comunidad de Madrid, Academy of Finland, China Scholarship Council, Wang, F. [0000-0001-5714-0010], Israel, David [0000-0003-2940-0617], Ramírez Valiente, José Alberto [0000-0002-5951-2938], Sánchez-Gómez, D. [0000-0002-0588-9713], Aranda, Ismael [0000-0001-9086-7940], Aphalo, Pedro J. [0000-0003-3385-972X], Robson, T. M. [0000-0002-8631-796X], Wang, Fang, Israel, David, Ramírez Valiente, José Alberto, Sánchez-Gómez, D., Aranda García, Ismael, Aphalo, Pedro J., Robson, T. M., University of Helsinki, Helsinki University Hospital, Bavarian Office for Forestry Seed and Plant Breeding, Southern Swedish Forest Research Centre, Ministerio de Educación y Ciencia (España), Comunidad de Madrid, Academy of Finland, China Scholarship Council, Wang, F. [0000-0001-5714-0010], Israel, David [0000-0003-2940-0617], Ramírez Valiente, José Alberto [0000-0002-5951-2938], Sánchez-Gómez, D. [0000-0002-0588-9713], Aranda, Ismael [0000-0001-9086-7940], Aphalo, Pedro J. [0000-0003-3385-972X], Robson, T. M. [0000-0002-8631-796X], Wang, Fang, Israel, David, Ramírez Valiente, José Alberto, Sánchez-Gómez, D., Aranda García, Ismael, Aphalo, Pedro J., and Robson, T. M.
- Abstract
Key message: Local adaptation largely segregates between traits affecting light responses and water relations, but population-level differences in stomatal conductance when growth is unconstrained converge among populations under water stress. Abstract: Warming temperatures and altered precipitation patterns threaten plant populations worldwide. European beech (Fagus sylvatica) is a species that expresses both high phenotypic plasticity and local adaptation among populations. Beech seedlings’ susceptibility to prolonged drought may be dictated by their immediate light environment. We tested whether seedlings of four beech provenances, from contrasting edaphoclimatic environments, expressed differences in trait responses to imposed water stress under sun and shade treatments. Populations from the southern range margin were expected to display greater water-stress tolerance and core populations’ faster growth rates in the absence of abiotic limitations. Both high light and water stress induced differences in trait responses among provenances, but traits that failed to respond to our experimental treatments likewise did not segregate at the provenance level. Hence, those traits responding to light, e.g., increasing leaf flavonol index and leaf mass area, also tended to differ among provenances. Similarly, there was evidence of local adaptation among provenances in traits, like midday leaf water potential, responding to water stress. Exceptionally, there was a three way interaction water- × -light- × -provenance for stomatal conductance which converged among provenances under water stress. Leaf chlorophyll content also varied both with light and water in a provenance-specific manner. We found core provenances’ growth traits to outperform others under favourable conditions, whereas southern and high-elevation populations displayed traits adapted to tolerate high irradiance. Only stomatal conductance produced a complementary interactive response between light- × -water ac
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- 2020
10. Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change:UNEP Environmental Effects Assessment Panel, Update 2021
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Barnes, P. W., Robson, T. M., Neale, P. J., Williamson, C. E., Zepp, R. G., Madronich, S., Wilson, S. R., Andrady, A. L., Heikkilä, A. M., Bernhard, G. H., Bais, A. F., Neale, R. E., Bornman, J. F., Jansen, M. A. K., Klekociuk, A. R., Martinez-Abaigar, J., Robinson, S. A., Wang, Q.-W., Banaszak, A. T., Häder, D.-P., Hylander, S., Rose, K. C., Wängberg, S.-Å., Foereid, B., Hou, W.-C., Ossola, R., Paul, N. D., Ukpebor, J. E., Andersen, M. P. S., Longstreth, J., Schikowski, T., Solomon, K. R., Sulzberger, B., Bruckman, L. S., Pandey, K. K., White, C. C., Zhu, L., Zhu, M., Aucamp, P. J., Liley, J. B., McKenzie, R. L., Berwick, M., Byrne, S. N., Hollestein, L. M., Lucas, R. M., Olsen, C. M., Rhodes, L. E., Yazar, S., Young, A. R., Barnes, P. W., Robson, T. M., Neale, P. J., Williamson, C. E., Zepp, R. G., Madronich, S., Wilson, S. R., Andrady, A. L., Heikkilä, A. M., Bernhard, G. H., Bais, A. F., Neale, R. E., Bornman, J. F., Jansen, M. A. K., Klekociuk, A. R., Martinez-Abaigar, J., Robinson, S. A., Wang, Q.-W., Banaszak, A. T., Häder, D.-P., Hylander, S., Rose, K. C., Wängberg, S.-Å., Foereid, B., Hou, W.-C., Ossola, R., Paul, N. D., Ukpebor, J. E., Andersen, M. P. S., Longstreth, J., Schikowski, T., Solomon, K. R., Sulzberger, B., Bruckman, L. S., Pandey, K. K., White, C. C., Zhu, L., Zhu, M., Aucamp, P. J., Liley, J. B., McKenzie, R. L., Berwick, M., Byrne, S. N., Hollestein, L. M., Lucas, R. M., Olsen, C. M., Rhodes, L. E., Yazar, S., and Young, A. R.
- Abstract
The Environmental Effects Assessment Panel of the Montreal Protocol under the United Nations Environment Programme evaluates effects on the environment and human health that arise from changes in the stratospheric ozone layer and concomitant variations in ultraviolet (UV) radiation at the Earth’s surface. The current update is based on scientific advances that have accumulated since our last assessment (Photochem and Photobiol Sci 20(1):1–67, 2021). We also discuss how climate change affects stratospheric ozone depletion and ultraviolet radiation, and how stratospheric ozone depletion affects climate change. The resulting interlinking effects of stratospheric ozone depletion, UV radiation, and climate change are assessed in terms of air quality, carbon sinks, ecosystems, human health, and natural and synthetic materials. We further highlight potential impacts on the biosphere from extreme climate events that are occurring with increasing frequency as a consequence of climate change. These and other interactive effects are examined with respect to the benefits that the Montreal Protocol and its Amendments are providing to life on Earth by controlling the production of various substances that contribute to both stratospheric ozone depletion and climate change.
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- 2022
11. Plant Response Traits Mediate the Effects of Subalpine Grasslands on Soil Moisture
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Gross, N., Robson, T. M., Lavorel, S., Albert, C., Le Bagousse-Pinguet, Y., and Guillemin, R.
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- 2008
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12. Summary Update 2021 for Policymakers: UNEP Environmental Effects Assessment Panel
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Barnes, P W, Bornman, J F, Pandey, K K, Bernhard, G H, Neale, R E, Robinson, Sharon A, Neale, P J, Zepp, R G, Madronich, S, White, C C, Andersen, M P S, Andrady, A L, Aucamp, P J, Bais, A F, Banaszak, A T, Berwick, M, Bruckman, L S, Byrne, S N, Foereid, B, Häder, D-P, Heikkilä, A M, Hollestein, L M, Hou, W-C, Hylander, S, Jansen, M A K, Klekociuk, A R, Liley, J B, Longstreth, J, Lucas, R M, Martinez-Abaigar, J, McKenzie, R L, McNeill, K, Olsen, C M, Ossola, R, Paul, N D, Rhodes, L E, Robson, T M, Rose, K C, Schikowski, T, Solomon, K R, Sulzberger, B, Ukpebor, J E, Wang, Q-W, Wängberg, S-Å, Williamson, C E, Wilson, S. R., Yazar, S, Young, A R, Zhu, L, Zhu, M, Barnes, P W, Bornman, J F, Pandey, K K, Bernhard, G H, Neale, R E, Robinson, Sharon A, Neale, P J, Zepp, R G, Madronich, S, White, C C, Andersen, M P S, Andrady, A L, Aucamp, P J, Bais, A F, Banaszak, A T, Berwick, M, Bruckman, L S, Byrne, S N, Foereid, B, Häder, D-P, Heikkilä, A M, Hollestein, L M, Hou, W-C, Hylander, S, Jansen, M A K, Klekociuk, A R, Liley, J B, Longstreth, J, Lucas, R M, Martinez-Abaigar, J, McKenzie, R L, McNeill, K, Olsen, C M, Ossola, R, Paul, N D, Rhodes, L E, Robson, T M, Rose, K C, Schikowski, T, Solomon, K R, Sulzberger, B, Ukpebor, J E, Wang, Q-W, Wängberg, S-Å, Williamson, C E, Wilson, S. R., Yazar, S, Young, A R, Zhu, L, and Zhu, M
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- 2021
13. The effects of snow-N deposition and snowmelt dynamics on soil-N cycling in marginal terraced grasslands in the French Alps
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Clement, J. C., Robson, T. M., Guillemin, R., Saccone, P., Lochet, J., Aubert, S., and Lavorel, S.
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- 2012
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14. Blue radiation stimulates photosynthetic induction in Fagus sylvatica L.
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Košvancová-Zitová, M., Urban, O., Navrátil, M., Špunda, V., Robson, T. M., and Marek, M. V.
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- 2009
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15. Importance and direction of current and future plant-UVresearch
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Barnes, P. W., Jansen, M. A. K., Jenkins, G. I., Vandenbussche, F., Brelsford, C. C., Banaś, Agnieszka, Bilger, W., Castagna, A., Festi, D., Gaberščik, A., Germ, M., Golob, A., Hauser, M.-T., Llorens, L., Martinez-Abaigar, J., Morales, L. O., Neugart, S., Pieristè, M., Rai, N., Ryan, L., Santin, M., Seddon, A. W. R., Stelzner, J., Tavridou, E., Łabuz, Justyna, and Robson, T. M.
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- 2018
16. Phenotypic trait variation measured on European genetic trials of Fagus sylvatica L
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Kraigher, Hojka [0000-0001-5696-2178], Fady, Bruno [0000-0003-2379-7617], Robson, T. M., Garzón, M. B., Alía Miranda, Ricardo, Egido, D. B., Bogdan, S., Borovics, A., Božič, Gregor, Brendel, O., Clark, Jo, De Vries, S. M. G., Delehan, I. I., Ducousso, A., Fady, Bruno, Fennessy, J., Forstreuter, M., Frýdl, J., Geburek, T., Gömöry, D., Hauke-Kowalska, M., Huber, Gerhard, Ibáñez, Juan Ignacio, Ioniţă, L., Ivanković, Mladen, Hansen, John K., Kóczán-Horváth, A., Kraigher, Hojka, Lee, Steve, Liesebach, M., Mátyás, C., Mertens, Patrick, Muhs, H. J., Novotný, P., Parnuţa, G., Paule, L., Picardo, A., Rasztovits, E., Rogge, M., Stener, L. G., Sułkowska, M., Urban, O., Von Wuehlisch, G., Vendramin, G. G., Vettori, C., Wesoły, W., Kraigher, Hojka [0000-0001-5696-2178], Fady, Bruno [0000-0003-2379-7617], Robson, T. M., Garzón, M. B., Alía Miranda, Ricardo, Egido, D. B., Bogdan, S., Borovics, A., Božič, Gregor, Brendel, O., Clark, Jo, De Vries, S. M. G., Delehan, I. I., Ducousso, A., Fady, Bruno, Fennessy, J., Forstreuter, M., Frýdl, J., Geburek, T., Gömöry, D., Hauke-Kowalska, M., Huber, Gerhard, Ibáñez, Juan Ignacio, Ioniţă, L., Ivanković, Mladen, Hansen, John K., Kóczán-Horváth, A., Kraigher, Hojka, Lee, Steve, Liesebach, M., Mátyás, C., Mertens, Patrick, Muhs, H. J., Novotný, P., Parnuţa, G., Paule, L., Picardo, A., Rasztovits, E., Rogge, M., Stener, L. G., Sułkowska, M., Urban, O., Von Wuehlisch, G., Vendramin, G. G., Vettori, C., and Wesoły, W.
- Abstract
We present BeechCOSTe52; a database of European beech (Fagus sylvatica) phenotypic measurements for several traits related to fitness measured in genetic trials planted across Europe. The dataset was compiled and harmonized during the COST-Action E52 (2006–2010), and subsequently cross-validated to ensure consistency of measurement data among trials and provenances. Phenotypic traits (height, diameter at breast height, basal diameter, mortality, phenology of spring bud burst and autumn–leaf discoloration) were recorded in 38 trial sites where 217 provenances covering the entire distribution of European beech were established in two consecutive series (1993/95 and 1996/98). The recorded data refer to 862,095 measurements of the same trees aged from 2 to 15 years old over multiple years. This dataset captures the considerable genetic and phenotypic intra-specific variation present in European beech and should be of interest to researchers from several disciplines including quantitative genetics, ecology, biogeography, macroecology, adaptive management of forests and bioeconomy.We present BeechCOSTe52; a database of European beech (Fagus sylvatica) phenotypic measurements for several traits related to fitness measured in genetic trials planted across Europe. The dataset was compiled and harmonized during the COST-Action E52 (2006–2010), and subsequently cross-validated to ensure consistency of measurement data among trials and provenances. Phenotypic traits (height, diameter at breast height, basal diameter, mortality, phenology of spring bud burst and autumn–leaf discoloration) were recorded in 38 trial sites where 217 provenances covering the entire distribution of European beech were established in two consecutive series (1993/95 and 1996/98). The recorded data refer to 862,095 measurements of the same trees aged from 2 to 15 years old over multiple years. This dataset captures the considerable genetic and phenotypic intra-specific variation present in European beec
- Published
- 2018
17. Increased root investment can explain the higher survival of seedlings of 'mesic' Quercus suber than 'xeric' Quercus ilex in sandy soils during a summer drought
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Ramírez Valiente, José Alberto, Aranda García, Ismael, Sanchéz-Gómez, D., Rodríguez-Calcerrada, J., Valladares, F., Robson, T. M., Ramírez Valiente, José Alberto, Aranda García, Ismael, Sanchéz-Gómez, D., Rodríguez-Calcerrada, J., Valladares, F., and Robson, T. M.
- Abstract
In Mediterranean-type ecosystems, drought is considered the main ecological filter for seedling establishment. The evergreen oaks Quercus ilex L. and Quercus suber L. are two of the most abundant tree species in the Mediterranean Basin. Despite their shared evergreen leaf habit and ability to resist low soil water potentials, traditionally it has been suggested that Q. ilex is better suited to resist dry conditions than Q. suber. In this study, we examined how seedlings of Q. ilex and Q. suber grown in sandy soils responded to different levels of water availability using natural dry conditions and supplemental watering. Specifically, we estimated survival and water status of seedlings and explored the role of acorn mass and belowground biomass in seedling performance. To our surprise, Q. suber was better able to survive the summer drought in our experiment than Q. ilex. Nearly 55% of the Q. suber seedlings remained alive after a 2-month period without rain or supplemental water, which represents almost 20% higher survival than Q. ilex over the same period. At the end of the dry period, the surviving seedlings of Q. suber had strikingly higher water potential, potential maximum quantum yield of photosystem II (Fv/Fm) and stomatal conductance (gs) than those of Q. ilex. Acorn mass was associated with the probability of survival under dry conditions; however, it did not explain the differences in survival or water status between the species. In contrast, Q. suber had a higher root ratio and root:shoot ratio than Q. ilex and these traits were positively associated with predawn leaf water potential, Fv/Fm, gs and survival. Taken together, our results suggest that the higher relative investment in roots by Q. suber when growing in a sandy acidic substrate allowed this species to maintain better physiological status and overall condition than Q. ilex, increasing its probability of survival in dry conditions
- Published
- 2018
18. The importance and direction of current and future plant-UV research
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Barnes, Paul W., Morales, Luis Orlando, Robson, T. M., Barnes, Paul W., Morales, Luis Orlando, and Robson, T. M.
- Abstract
Background To stimulate how to move the field of plant-UV research forward, and create a coherent framework to highlight valuable future directions in plant UV research we had a group discussion of the most prescient questions and how to address them. The following sections are broken-down into those from the molecular, biochemical and physiological discussions followed by those from the ecological and plant production discussions. In each case, first basic research questions are considered and then applications and methodological considerations put forward. Finally, some common ground bringing together the two perspectives is proposed, aimed at solving scaling problems and ways in which the UV4Plants network might be put to good use.
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- 2018
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19. Intra-specific variability and plasticity influence potential tree species distributions under climate change
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Benito Garzón, M., Alía Miranda, Ricardo, Robson, T. M., and Zavala, M. A.
- Subjects
Global warming ,Local adaptation ,Pinus pinaster ,Pinus sylvestris ,Phenotypic plasticity ,Species distribution models ,Iberian Peninsula - Abstract
Aim To assess the effect of local adaptation and phenotypic plasticity on the potential distribution of species under future climate changes. Trees may be adapted to specific climatic conditions; however, species range predictions have classically been assessed by species distribution models (SDMs) that do not account for intra-specific genetic variability and phenotypic plasticity, because SDMs rely on the assumption that species respond homogeneously to climate change across their range, i.e. a species is equally adapted throughout its range, and all species are equally plastic. These assumptions could cause SDMs to exaggerate or underestimate species at risk under future climate change. Location The Iberian Peninsula. Methods Species distributions are predicted by integrating experimental data and modelling techniques. We incorporate plasticity and local adaptation into a SDM by calibrating models of tree survivorship with adaptive traits in provenance trials. Phenotypic plasticity was incorporated by calibrating our model with a climatic index that provides a measure of the differences between sites and provenances. Results We present a new modelling approach that is easy to implement and makes use of existing tree provenance trials to predict species distribution models under global warming. Our results indicate that the incorporation of intra-population genetic diversity and phenotypic plasticity in SDMs significantly altered their outcome. In comparing species range predictions, the decrease in area occupancy under global warming conditions is smaller when considering our survival-adaptation model than that predicted by a 'classical SDM' calibrated with presence-absence data. These differences in survivorship are due to both local adaptation and plasticity. Differences due to the use of experimental data in the model calibration are also expressed in our results we incorporate a null model that uses survival data from all provenances together. This model always predicts less reduction in area occupancy for both species than the SDM calibrated with presence-absence. Main conclusions We reaffirm the importance of considering adaptive traits when predicting species distributions and avoiding the use of occurrence data as a predictive variable. In light of these recommendations, we advise that existing predictions of future species distributions and their component populations must be reconsidered. © 2011 Blackwell Publishing Ltd.
- Published
- 2011
20. Land use in subalpine grasslands affects nitrogen cycling via changes in plant community and soil microbial uptake dynamics
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Robson, T. M., Baptist, F., Clément, J. C., and Lavorel, S.
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Plant functional types ,Traditional land use ,Marginal grasslands ,Traditional land use15N isotope ,food and beverages ,15N isotope ,N mineralization ,Microbial N ,Pool dilution - Abstract
1. Nitrogen (N) cycling is a key process determining ecosystem functioning in subalpine grasslands where traditional mowing and manuring are being abandoned. However, the roles of the plant and microbial communities in mediating changes in N availability are still poorly understood. 2. We inoculated 15 subalpine grassland fields with dual-labelled ammonium nitrate (15NH4+, 15NO3 -) during July 2005 and used pool dilutions over 1 month to calculate inorganic N fluxes into the microbial pool and uptake in plant communities by grasses, forbs and legumes. The effects of current land abandonment were assessed by comparing manured and mown terraces (ancient croplands) with other terraces where these practices have ceased, and mown versus unmown unterraced meadows. 3. Rapid cycling of inorganic N and high soil N availability in forb-dominated manured and mown terraces resulted from fast plant N uptake and low microbial CN ratio. In grass-dominated unmown terraces, N cycling was slower and N retention was greater; microbial N uptake remained similar to that in the other terraces, although a higher CN ratio suggested a shift towards fungal dominance. 4. In unterraced meadows, pH was low due to reduced mixing of soil with the underlying calcareous rock. Soil [NH4+] was high and [NO3-] low, but current management had no effect on N pool size, although plant N uptake was greater in the mown than unmown fields. This may be partially explained by high N retention by dominant Festuca paniculata tussocks. The microbial N pool and N uptake were both low and the microbial CN ratio was high, suggesting that fungi slowed N cycling and reduced the influence of mowing on N turnover. 5. Synthesis. In these marginal long-term grasslands, with low productivity and high biodiversity value, changes in ecosystem function associated with reduced management intensity were mediated through slower N cycling. This response was expressed as more gradual nutrient uptake but greater retention by unmown plant communities, slower microbial uptake and smaller soil N pools. In contrast to more productive ecosystems, such as north-western European grasslands, reduced management is detrimental to both biodiversity and the maintenance of soil-related ecosystem services. These costs will need to be balanced against potential benefits, such as carbon storage. © 2009 British Ecological Society.
- Published
- 2010
21. Differences in the leaf functional traits of six beech (Fagus sylvatica L.) populations are reflected in their response to water limitation
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Gil-Peregrín, Eustaquio [0000-0002-4053-6681], Sánchez-Gómez, D., Robson, T. M., Gascó, A., Gil-Pelegrín, Eustaquio, Aranda García, Ismael, Gil-Peregrín, Eustaquio [0000-0002-4053-6681], Sánchez-Gómez, D., Robson, T. M., Gascó, A., Gil-Pelegrín, Eustaquio, and Aranda García, Ismael
- Abstract
Patterns of intraspecific variation in functional traits have been widely studied across plant species to find out what general suites of traits provide functional advantage under specific environmental conditions. Much less is known about this variation within tree species and, in particular, about its relationship with performance variables such as photosynthetic rates under water deficit. Nevertheless, this knowledge is fundamental to understand the adaptive potential of drought sensitive tree species to increased aridity as predicted in the context of climate change. Intraspecific variation in photosynthetic performance and other leaf functional traits in response to water availability were examined in a glasshouse experiment using seedlings of six European beech populations. The physiological response of seedlings to a "water stress" treatment was compared to a "control" treatment along an experimental cycle of progressive soil water deficit and recovery. We found evidence of intraspecific variation in beech's photosynthetic performance and other leaf functional traits in response to water availability. We also detected intraspecific variation in leaf-level tolerance of water deficit and phenotypic plasticity to water availability suggesting a pattern shaped by both regional and local scale effects. The Swedish population was particularly sensitive to water deficit, being the only population showing impaired photochemical efficiency under the experimental water deficit. Leaf-level tolerance of water deficit was related to PNUE, but not to other functional traits, such as WUE, SLA or leaf nitrogen content, that have been described to vary across species in adaptation to drought tolerance. Our results support the idea that general trends for variation in functional traits across species do not necessarily reflect a similar pattern when observed at the intraspecific level. The observed functional variation between beech populations reaffirms the importance of loca
- Published
- 2013
22. Flushing phenology and fitness of European beech (Fagus sylvatica L.) provenances from a trial in La Rioja, Spain, segregate according to their climate of origin
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Robson, T. M., Rasztovits, E., Aphalo, Pedro J., Alía Miranda, Ricardo, Aranda García, Ismael, Robson, T. M., Rasztovits, E., Aphalo, Pedro J., Alía Miranda, Ricardo, and Aranda García, Ismael
- Abstract
European beech (Fagus sylvatica) reaches the south-western limit of its distribution in northern Spain, beyond which the Mediterranean climate is thought to restrict further expansion of the species range. Consequently, current and future climate change in the region is expected to push back the range margin and threaten the survival of local beech populations. In a provenance trial of pan-European beech populations growing under harsh conditions in La Rioja, we tested whether associations between the timing of spring phenology assessed over three years affected the performance of beeches at the site, and whether they exhibited a trade off between growth rate and survival. In particular, we considered whether the relationship between performance under conditions of summer drought and spring frost at the trial site was dependent on the climate at the site of provenance origin. We report that early-flushing provenances from continental climates in the south-east and parts of central Europe were among the tallest after ten years of growth in the trial for instance from Val di Sella, northern Italy (mean bud burst day 114 and height 173. cm); Gotze Delchev, Bulgaria (day 115, height 135. cm); and Aarberg, Switzerland (day 118, height 151. cm). While late-flushing provenances from maritime climates in northern and western Europe were among the shortest in the trial for instance from Soignes, Belgium (day 124, height 73. cm); Gullmarsberg, Sweden (day 122, height 69. cm); and Bathurst Estate, southern England (day 122, height 85. cm). There was no evidence that early flushing increased the mortality of trees at the trial site. The large-scale geographical patterns in flushing strategy reflected a trade off between pre-emptive growth before the summer drought and susceptibility to late frosts. Our findings emphasise the need to conserve populations from the range edge in the south of Europe, the Balkans and western Alps, whose combination of early flushing and drought resi
- Published
- 2013
23. Comparison of inorganic nitrogen uptake dynamics following snowmelt and at peak biomass in subalpine grasslands
- Author
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Legay, N., primary, Grassein, F., additional, Robson, T. M., additional, Personeni, E., additional, Bataillé, M.-P., additional, Lavorel, S., additional, and Clément, J.-C., additional
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- 2013
- Full Text
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24. Land use in subalpine grasslands affects nitrogen cycling via changes in plant community and soil microbial uptake dynamics
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Lavorel, Sandra [0000-0002-7300-2811], Robson, T. M., Baptist, F., Clément, J. C., Lavorel, Sandra, Lavorel, Sandra [0000-0002-7300-2811], Robson, T. M., Baptist, F., Clément, J. C., and Lavorel, Sandra
- Abstract
1. Nitrogen (N) cycling is a key process determining ecosystem functioning in subalpine grasslands where traditional mowing and manuring are being abandoned. However, the roles of the plant and microbial communities in mediating changes in N availability are still poorly understood. 2. We inoculated 15 subalpine grassland fields with dual-labelled ammonium nitrate (15NH4+, 15NO3 -) during July 2005 and used pool dilutions over 1 month to calculate inorganic N fluxes into the microbial pool and uptake in plant communities by grasses, forbs and legumes. The effects of current land abandonment were assessed by comparing manured and mown terraces (ancient croplands) with other terraces where these practices have ceased, and mown versus unmown unterraced meadows. 3. Rapid cycling of inorganic N and high soil N availability in forb-dominated manured and mown terraces resulted from fast plant N uptake and low microbial CN ratio. In grass-dominated unmown terraces, N cycling was slower and N retention was greater; microbial N uptake remained similar to that in the other terraces, although a higher CN ratio suggested a shift towards fungal dominance. 4. In unterraced meadows, pH was low due to reduced mixing of soil with the underlying calcareous rock. Soil [NH4+] was high and [NO3-] low, but current management had no effect on N pool size, although plant N uptake was greater in the mown than unmown fields. This may be partially explained by high N retention by dominant Festuca paniculata tussocks. The microbial N pool and N uptake were both low and the microbial CN ratio was high, suggesting that fungi slowed N cycling and reduced the influence of mowing on N turnover. 5. Synthesis. In these marginal long-term grasslands, with low productivity and high biodiversity value, changes in ecosystem function associated with reduced management intensity were mediated through slower N cycling. This response was expressed as more gradual nutrient uptake but greater retention by unmow
- Published
- 2010
25. Summer drought impedes beech seedling performance more in a sub-Mediterranean forest understory than in small gaps
- Author
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Robson, T. M., Rodríguez-Calcerrada, J., Sánchez-Gómez, D., Aranda García, Ismael, Robson, T. M., Rodríguez-Calcerrada, J., Sánchez-Gómez, D., and Aranda García, Ismael
- Abstract
Refugia of mixed beech forest persist in the central mountains of the Iberian Peninsula at the south-western limit of European beech (Fagus sylvatica L.) distribution. The lack of beech regeneration is a concern in this region that has experienced reduced rainfall and higher temperatures over the past 30 years. Beech is considered especially susceptible to climate change because of its conservative shade-tolerant growth strategy; hence seedling responses to drought stress in gaps and in the understory are of particular interest. During the summer of 2007, a watering treatment raised the soil water content by up to 5% in gap and understory plots of beech seedlings in a mixed beech forest. Root-collar diameter was increased by our watering treatment in understory seedlings. Neither drought-avoidance through stomatal closure nor physiological drought-tolerance mechanisms were able to mitigate the effects of water stress in the understory seedlings, whereas osmotic adjustment enhanced the ability of the gap seedlings to tolerate water stress. Overall, high photosynthetic rates in the gaps, despite the photoinhibitory effects of high radiation, allowed gap seedlings to survive and grow better than the understory seedlings irrespective of water availability. Our results indicate that further intensification of summer drought, predicted for the Iberian Peninsula, will hinder the establishment of a beech seedling bank in the understory because of the conflicting seedling trait responses to simultaneously withstand water stress and to tolerate shade.
- Published
- 2009
26. Limited capacity to cope with excessive light in the open and with seasonal drought in the shade in Mediterranean Ilex aquifolium populations
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Aranda García, Ismael, Robson, T. M., Rodríguez-Calcerrada, J., Valladares Ros, Fernando, Aranda García, Ismael, Robson, T. M., Rodríguez-Calcerrada, J., and Valladares Ros, Fernando
- Abstract
Climate change is expected to involve more-frequent and intense summer droughts in the Mediterranean region. This represents a threat for long-term persistence of woody species, such as European holly (Ilex aquifolium), that originated under humid climates during the Tertiary period. The capacity of this species to persist under increased water stress, both in gaps and in the understory of an oak-dominated woodland, was assessed by quantifying phenotypic plasticity in response to drought and shade. Physiological responses in plant-water relations and gas exchange were used as performance indicators under the different environments. Phenotypic plasticity of drought-stressed holly trees in response to changes in the light environment was low relative to the known response of co-occurring forest trees. Differences between morphological traits (e.g. specific leaf area and leaf sapwood ratio in twigs) of sun- and shade-grown trees were small but significant while physiological traits were largely unresponsive to light availability. This supports the hypothesis that late-successional shade-tolerant species exhibit greater morphological than physiological plasticity. Sapling acclimation capacity through physiological mechanisms such as osmotic adjustment was insufficient to protect from summer drought. Holly mainly inhabits oceanic climates where extreme temperatures and droughts are unusual. Our results suggest that the species occupies a narrowing niche in continental Mediterranean habitats, and may lack the capacity to persist under more-severe future climate scenarios because of its low phenotypic plasticity in response to light and drought stresses. © 2007 Springer-Verlag.
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- 2008
27. Supplementary material to "Comparison of inorganic nitrogen uptake dynamics following snowmelt and at peak biomass in subalpine grasslands"
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Legay, N., primary, Grassein, F., additional, Robson, T. M., additional, Personeni, E., additional, Bataillé, M.-P., additional, Lavorel, S., additional, and Clément, J.-C., additional
- Published
- 2013
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28. Incorporating plant functional diversity effects in ecosystem service assessments
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de Bello, Francesco [0000-0001-9202-8198], Lavorel, Sandra [0000-0002-7300-2811], Díaz, Sandra [0000-0003-4061-072X], Díaz, Sandra, Lavorel, Sandra, de Bello, Francesco, Quétier, F., Grigulis, K., Robson, T. M., de Bello, Francesco [0000-0001-9202-8198], Lavorel, Sandra [0000-0002-7300-2811], Díaz, Sandra [0000-0003-4061-072X], Díaz, Sandra, Lavorel, Sandra, de Bello, Francesco, Quétier, F., Grigulis, K., and Robson, T. M.
- Abstract
Global environmental change affects the sustained provision of a wide set of ecosystem services. Although the delivery of ecosystem services is strongly affected by abiotic drivers and direct land use effects, it is also modulated by the functional diversity of biological communities (the value, range, and relative abundance of functional traits in a given ecosystem). The focus of this article is on integrating the different possible mechanisms by which functional diversity affects ecosystem properties that are directly relevant to ecosystem services. We propose a systematic way for progressing in understanding how land cover change affects these ecosystem properties through functional diversity modifications. Models on links between ecosystem properties and the local mean, range, and distribution of plant trait values are numerous, but they have been scattered in the literature, with varying degrees of empirical support and varying functional diversity components analyzed. Here we articulate these different components in a single conceptual and methodological framework that allows testing them in combination. We illustrate our approach with examples from the literature and apply the proposed framework to a grassland system in the central French Alps in which functional diversity, by responding to land use change, alters the provision of ecosystem services important to local stakeholders. We claim that our framework contributes to opening a new area of research at the interface of land change science and fundamental ecology. © 2007 by The National Academy of Sciences of the USA.
- Published
- 2007
29. The effects of snow-N deposition and snowmelt dynamics on soil-N cycling in marginal terraced grasslands in the French Alps
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Clement, J. C., primary, Robson, T. M., additional, Guillemin, R., additional, Saccone, P., additional, Lochet, J., additional, Aubert, S., additional, and Lavorel, S., additional
- Published
- 2011
- Full Text
- View/download PDF
30. Thermal acclimation of leaf dark respiration of beech seedlings experiencing summer drought in high and low light environments
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Rodriguez-Calcerrada, J., primary, Atkin, O. K., additional, Robson, T. M., additional, Zaragoza-Castells, J., additional, Gil, L., additional, and Aranda, I., additional
- Published
- 2009
- Full Text
- View/download PDF
31. Summer drought impedes beech seedling performance more in a sub-Mediterranean forest understory than in small gaps
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Robson, T. M., primary, Rodriguez-Calcerrada, J., additional, Sanchez-Gomez, D., additional, and Aranda, I., additional
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- 2008
- Full Text
- View/download PDF
32. Impacts of solar ultraviolet-B radiation on terrestrial ecosystems of Tierra del Fuego (southern Argentina). An overview of recent progress.
- Author
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Ballaré CL, Rousseau MC, Searles PS, Zaller JG, Giordano CV, Robson TM, Caldwell MM, Sala OE, and Scopel AL
- Subjects
- Animals, Argentina, Chlorophyll radiation effects, Plants radiation effects, Ecosystem, Sunlight, Ultraviolet Rays
- Abstract
The southern part of Tierra del Fuego, in the southernmost tip of South America, is covered by dense Nothofagus spp. forests and Sphagnum-dominated peat bogs, which are subjected to the influence of ozone depletion and to increased levels of solar ultraviolet-B radiation (UV-B). Over the last 5 years we have studied some of the biological impacts of solar UV-B on natural ecosystems of this region. We have addressed two general problems: (i) do the fluctuations in UV-B levels under the influence of the Antarctic ozone 'hole' have any measurable biological impact, and (ii) what are the long-term effects of solar (ambient) UV-B on the Tierra del Fuego ecosystems? In this paper, we provide an overview of the progress made during the first 4 years of the project. We highlight and discuss the following results: (1) ambient UV-B has subtle but significant inhibitory effects on the growth of herbaceous and graminoid species of this region (growth reduction < or = 12%), whereas no consistent inhibitory effects could be detected in woody perennials; (2) in the species investigated in greatest detail, Gunnera magellanica, the inhibitory effect of solar UV-B is accompanied by increased levels of DNA damage in leaf tissue, and the DNA damage density in the early spring is clearly correlated with the dose of weighted UV-B measured at ground level; (3) the herbaceous species investigated thus far show little or no acclimation responses to ambient UV-B such as increased sunscreen levels and DNA repair capacity; and (4) ambient UV-B has significant effects on heterotrophic organisms, included marked inhibitory effects on insect herbivory. The results from the experiments summarized in this review clearly indicate that UV-B influences several potentially important processes and ecological interactions in the terrestrial ecosystems of Tierra del Fuego.
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- 2001
- Full Text
- View/download PDF
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