title: Influence of air temperature on the first flowering date of Prunus yedoensis Matsum.
abstract: Climate change is expected to have a significant effect on the first flowering date (FFD) in plants flowering in early spring. Prunus yedoensis Matsum is a good model plant for analyzing this effect. In this study, we used a degree day model to analyze the effect of air temperatures on the FFDs of P. yedoensis at Wuhan University from a long-time series from 1951 to 2012. First, the starting date (=7 February) is determined according to the lowest correlation coefficient between the FFD and the daily average accumulated degree days (ADD). Second, the base temperature (=-1.2°C) is determined according to the lowest root mean square error (RMSE) between the observed and predicted FFDs based on the mean of 62-year ADDs. Finally, based on this combination of starting date and base temperature, the daily average ADD of every year was calculated. Performing a linear fit of the daily average ADD to year, we find that there is an increasing trend that indicates climate warming from a biological climatic indicator. In addition, we find that the minimum annual temperature also has a significant effect on the FFD of P. yedoensis using the generalized additive model. This study provides a method for analyzing the climate change on the FFD in plants' flowering in early spring.
authors.affiliation: Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences Qingdao, 266071, China.
authors.forename: Peijian
authors.initials: P
authors.lastname: Shi
authors.affiliation: Wuhan Institute of Heavy Rain, China Meteorological Administration Wuhan, 430074, China.
authors.forename: Zhenghong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: College of Forestry, Jiangxi Agricultural University Nanchang, 330045, China.
authors.forename: Qingpei
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Entomology, Texas A&M University College Station, TX, 77843.
authors.forename: Marvin K
authors.initials: MK
authors.lastname: Harris
authors.affiliation: College of Resource and Environmental Sciences, Wuhan University Wuhan, 430072, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Xiao
keywords: Accumulated degree days (ADD); base temperature; correlation coefficient; root mean square error; starting date