Asymmetric effects of daytime and night-time warming on Northern Hemisphere vegetation

• Published in: Nature
• Main Authors: Peng, Shushi, Piao, Shilong, Ciais, Philippe, Myneni, Ranga B., Chen, Anping, Chevallier, Frederic, Dolman, Albertus J., Janssens, Ivan A., Penuelas, Josep, Zhang, Gengxin, Vicca, Sara, Wan, Shiqiang, Wang, Shiping, Zeng, Hui
• Other Authors: Piao, SL (reprint author), Peking Univ, Coll Urban & Environm Sci, Sinofrench Inst Earth Syst Sci, Beijing 100871, Peoples R China., Peking Univ, Coll Urban & Environm Sci, Sinofrench Inst Earth Syst Sci, Beijing 100871, Peoples R China., Chinese Acad Sci, Inst Tibetan Plateau Res, Beijing 100085, Peoples R China., CEA, CNRS, LSCE, CE, F-91191 Gif Sur Yvette, France., Boston Univ, Dept Earth & Environm, Boston, MA 02215 USA., Princeton Univ, Dept Ecol & Evolutionary Biol, Princeton, NJ 08544 USA., Vrije Univ Amsterdam, Dept Earth Sci, NL-1081 HV Amsterdam, Netherlands., Univ Antwerp, Dept Biol, B-2610 Antwerp, Belgium., CREAF, Barcelona 08193, Catalonia, Spain., UAB, CSIC, CEAB, Global Ecol Unit,CREAF, Barcelona 08193, Catalonia, Spain., Henan Univ, Coll Life Sci, Kaifeng 475001, Peoples R China., Peking Univ, Shenzhen Grad Sch, Shenzhen 518055, Peoples R China.
• Format: Journal/Newspaper
• Language: English
• Published: nature 2013
• Subjects: NET PRIMARY PRODUCTION; CARBON-DIOXIDE; RIDGE REGRESSION; LEAF RESPIRATION; CLIMATE-CHANGE; SATELLITE; GROWTH; TEMPERATURE; IMPACT; MODEL; Barrow; Point Barrow; Alaska
• Online Access: https://hdl.handle.net/20.500.11897/322081; https://doi.org/10.1038/nature12434

Temperature data over the past five decades show faster warming of the global land surface during the night than during the day(1). This asymmetric warming is expected to affect carbon assimilation and consumption in plants, because photosynthesis in most plants occurs during daytime and is more sensitive to the maximum daily temperature, T-max, whereas plant respiration occurs throughout the day(2) and is therefore influenced by both T-max and the minimum daily temperature, T-min. Most studies of the response of terrestrial ecosystems to climate warming, however, ignore this asymmetric forcing effect on vegetation growth and carbon dioxide (CO2) fluxes(3-6). Here we analyse the interannual covariations of the satellite-derived normalized difference vegetation index (NDVI, an indicator of vegetation greenness) with Tmax and Tmin over the Northern Hemisphere. After removing the correlation between Tmax and Tmin, we find that the partial correlation between Tmax and NDVI is positive in most wet and cool ecosystems over boreal regions, but negative in dry temperate regions. In contrast, the partial correlation between Tmin and NDVI is negative in boreal regions, and exhibits a more complex behaviour in dry temperate regions. We detect similar patterns in terrestrial net CO2 exchange maps obtained from a global atmospheric inversion model. Additional analysis of the long-term atmospheric CO2 concentration record of the station Point Barrow in Alaska suggests that the peak-to-peak amplitude of CO2 increased by 23 +/- 11% for a +1 degrees C anomaly in T-max from May to September over lands north of 51 degrees N, but decreased by 28 +/- 14% for a +1 degrees C anomaly in T-min. These lines of evidence suggest that asymmetric diurnal warming, a process that is currently not taken into account in many global carbon cycle models, leads to a divergent response of Northern Hemisphere vegetation growth and carbon sequestration to rising temperatures. Multidisciplinary Sciences SCI(E) PubMed 21 ARTICLE 7465 88-+ 501