Phenological timings of leaf budburst with climate change in Japan

Phenological timing of leaf budburst in plants is important for growth, since early budburst timing extends the growth period of the plant. We estimated the effect of climate change on the phenological budburst timing of four trees throughout four sites in Japan, a region with few studies on this topic. The leaf budburst date of plants has advanced or been stable during the last five decades in these four Japanese localities. This fact is due to the negative relationship between dates and temperature using multiple regression models, observed at all sites. Climate change has shifted budburst phenology in Japan with the increase of spring temperatures. However, precipitation did not show any effect on budburst timing. At two budburst dates of three tree species had not remarkably changed or delayed through-sites, out the past five decades. There were differences between localities at the same latitude. (C) 2007 Elsevier B.V. All rights reserved.