Effects of changes in spring temperature on flowering dates of woody plants across China
- ISSN: 1817406X
In China, changes in the timing of plant phenological phases are influenced greatly by monsoonal climate fluctuations, and also vary with species and region. Observations of phenological phases of trees were conducted in the Phenological Observation Network of China from 1963 to 1988. Records of flowering dates of four species (Syringa oblata Lindl., Cercis chinensis Bunge, Robinia pseudoacacia L., Albizzia julibrissin Durazz) at ten sites, together with corresponding climate data, were used to investigate phenophase responses to variation in temperature. The ten sites extend over a wide area, with latitudes ranging from 25 degrees N to 46 degrees N, and altitudes ranging from 17 to 1,922 in a.s.l. Spring temperature was significantly related to flowering date of the trees under the monsoonal climate in the eastern Eurasian Continent. The period during which temperature influences flowering time varies from 60 to 90 days for Robinia pseudoacacia in the south to 30 to 40 days in the north, due to the shorter warm period before flowering in the north. The three other species showed similar trends of changes with latitude in the length of the period of temperature influence. The flowering season for Cercis chinensis in response to a temperature increase 30-60 days prior to flowering advanced from 2.7 to 5.9 days/degrees C in the low plain, and in response to a temperature increase 60-90 days prior to flowering, advanced from 7.1 to 14.8 days/degrees C in the Yunnan-Guizhou Plateau. The flowering for Syringa oblata, Robinia pseudoacacia and Albizzia julibrissin, in response to a temperature increase advanced in the range 2.7-4.9, 2.5-6.5, and 2.4-6.0 days/degrees C in the low plain, respectively. Flowering advanced by 4.7-12.4 days/degrees C for Robinia pseudoacacia and 13.1 days/degrees C for Albizzia julibrissin in the plateau.