Details

Autor(en) / Beteiligte

• Wolkovich, E. M.
• Cook, B. I.
• Allen, J. M.
• Crimmins, T. M.
• Betancourt, J. L.
• Travers, S. E.
• Pau, S.
• Regetz, J.
• Davies, T. J.
• Kraft, N. J. B.
• Ault, T. R.
• Bolmgren, K.
• Mazer, S. J.
• McCabe, G. J.
• McGill, B. J.
• Parmesan, C.
• Salamin, N.
• Schwartz, M. D.
• Cleland, E. E.

Titel

Warming experiments underpredict plant phenological responses to climate change

Ist Teil von

• Nature (London), 2012-05, Vol.485 (7399), p.494-497

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2012

Quelle

EBSCOhost Psychology and Behavioral Sciences Collection

Beschreibungen/Notizen

• Advances in plant flowering and leafing times in response to warming are underpredicted by experimental warming studies. Plant responses to a changing climate The timing of crucial events in plant life cycles is shifting in response to climate change, but studies differ in their assessment of the extent of this shift. Researchers use two main methods — experimental warming of plants and long-term records of flowering and leaf-production responses to interannual variation — to estimate and project responses, on the assumption that responses are consistent across these two methods. To test this assumption, Wolkovich et al . performed a meta-analysis of the literature. They find that overall, the experimental studies under-predict the advances in flowering and leafing times seen in the observational studies by 8.5 and 4.0 times respectively. This suggests that projections of how plants will change with increasing global warming are highly uncertain, and change may be greater than was thought. Warming experiments are increasingly relied on to estimate plant responses to global climate change 1 , 2 . For experiments to provide meaningful predictions of future responses, they should reflect the empirical record of responses to temperature variability and recent warming, including advances in the timing of flowering and leafing 3 , 4 , 5 . We compared phenology (the timing of recurring life history events) in observational studies and warming experiments spanning four continents and 1,634 plant species using a common measure of temperature sensitivity (change in days per degree Celsius). We show that warming experiments underpredict advances in the timing of flowering and leafing by 8.5-fold and 4.0-fold, respectively, compared with long-term observations. For species that were common to both study types, the experimental results did not match the observational data in sign or magnitude. The observational data also showed that species that flower earliest in the spring have the highest temperature sensitivities, but this trend was not reflected in the experimental data. These significant mismatches seem to be unrelated to the study length or to the degree of manipulated warming in experiments. The discrepancy between experiments and observations, however, could arise from complex interactions among multiple drivers in the observational data, or it could arise from remediable artefacts in the experiments that result in lower irradiance and drier soils, thus dampening the phenological responses to manipulated warming. Our results introduce uncertainty into ecosystem models that are informed solely by experiments and suggest that responses to climate change that are predicted using such models should be re-evaluated.