Variation of Main Phenophases in Phenological Calendar in East China and Their Response to Climate Change

Fengyi Zheng,Quansheng Ge,Junhu Dai,Yachen Liu,Zexing Tao,Yunjia Xu

doi:10.1155/2016/9546380

Abstract

Based on the phenological data from China Phenological Observation Network, we compiled the phenological calendars of 3 phenological observation stations (Shanghai, Nanjing, and Hefei) in East China for 1987–1996 and 2003–2012 according to the sequences of mean phenophases. We calculated the correlated coefficient and the root mean square error (RMSE) between phenophases and the beginning of meteorological seasons to determine the beginning date of phenological season. By comparing new phenological calendars with the old ones, we discussed the variation of phenophases and their responses to temperature. The conclusions are as follows. (1) The beginning dates of spring and summer advanced, while those of autumn and winter delayed. Thus, summers got longer and winters got shorter. (2) The beginning time of the four phenological seasons was advancing during 1987–1996, while it was delaying during 2003–2012. (3) Most spring and summer phenophases occur earlier and most autumn and winter phenophases occur later in 2003–2012 than in 1987–1996. (4) The beginning time of phenological seasons was significantly correlated with temperature. The phenological sensitivities to temperature ranged from −6.49 to −6.55 days/°C in spring, −3.65 to −5.02 days/°C in summer, 8.13 to 10.27 days/°C in autumn, and 4.76 to 10.00 days/°C in winter.

Highlights

Phenology is the study of periodic biological events affected by environment [1, 2]
Autumn and winter in the three stations started later in the latter period than in the former period, and the beginning time of autumn delayed by 16 days, 2 days, and 1 day and that of winter delayed by 14, 3, and 16 days in Shanghai, Nanjing, and Hefei, respectively
Regarding to the length of different seasons summarized from the two phenological calendars, it is learned that the length of all the four seasons changed regularly

Summary

Introduction

Phenology is the study of periodic biological events affected by environment [1, 2]. Besides instrumental measurements, phenology can reflect the impacts of climate change on the biological and physical systems independently [3] and is regarded as the fingerprints of global warming [4].Phenological calendar is a specialized calendar recording the sequence of phenological events, which is defined as lists of the starting dates and selected statistics of the phenological phases, their duration, and the intervals between them [5]. Phenology is the study of periodic biological events affected by environment [1, 2]. As one of the effective ways to divide the seasons, phenological season is defined by the sequence of various phenophases in a year. Wan [8, 9] set a standard to divide one year into 4 phenological seasons (spring, summer, autumn, and winter) and compiled the phenological calendar of the cities in China Phenological Observation Network (CPON) during 1963–1985. It is necessary to compile new phenological calendars to reflect the phenological characters in different regions. People have compiled new phenological calendars in Beijing and Harbin, China [12, 13], but the work in other regions was not reported. Previous phenological studies mainly focused on phenological variation in temperate regions at middle and high latitudes and revealed that most of the spring phenophases advanced while phenophases in autumn

Methods

Results

Discussion

Conclusion