Spatial and temporal changes in leaf coloring date of Acer palmatum and Ginkgo biloba in response to temperature increases in South Korea

Abstract

Understanding shifts in autumn phenology associated with climate changes is critical for preserving forest ecosystems. This study examines the changes in the leaf coloring date (LCD) of two temperate deciduous tree species, Acer palmatum (Acer) and Ginkgo biloba (Ginkgo), in response to surface air temperature (Ts) changes at 54 stations of South Korea for the period 1989–2007. The variations of Acer and Ginkgo in South Korea are very similar: they show the same mean LCD of 295th day of the year and delays of about 0.45 days year-1 during the observation period. The delaying trend is closely correlated (correlation coefficient > 0.77) with increases in Ts in mid-autumn by 2.8 days °C-1. It is noted that the LCD delaying and temperature sensitivity (days °C-1) for both tree species show negligible dependences on latitudes and elevations. Given the significant LCD-Ts relation, we project LCD changes for 2016–35 and 2046–65 using a process-based model forced by temperature from climate model simulation. The projections indicate that the mean LCD would be further delayed by 3.2 (3.7) days in 2016–35 (2046–65) due to mid-autumn Ts increases. This study suggests that the mid-autumn warming is largely responsible for the observed LCD changes in South Korea and will intensify the delaying trends in the future.

Asymmetric Expansion of Summer Season on May and September in Korea

“…Notice that plant phenology is the timing of plant activity. Phenological events are sensitive to the variations in climate variables, especially to variations in temperature (Ho et al 2006;Jeong et al 2009;Park et al 2017). Therefore, it is suggested that the observed asymmetric warming trends in spring and autumn during the last century affected the spring and autumn plant phenology in Korea.…”

“…The atmospheric pressure field changes might alter the beginning and ending dates of seasons. The changes in the timing of plant activity (i.e., plant phenology), such as advanced flowering in spring and delayed leaf coloring in autumn, indicated shifts in the conventional seasons (Ho et al 2006;Jeong et al 2011;Park et al 2017). Therefore, further investigation of seasonal warming, especially in spring and autumn, with a focus on the shift of seasons is needed.…”

How did the characteristics of the growing season change during the past 100 years at a steep river basin in Japan?

“…Previous studies examined the spatiotemporal distribution of the timing of leaf flushing, leaf colouring, and leaf fall along an elevational gradient using data from in situ observations [14][15][16][17], phenological images [7,18,19], herbarium records [10], phenological information published on the Internet [9], data from satellite observations [6,12,[20][21][22][23], and modelling [24,25]. The scales of the targeted regions have been national (Germany [15], Slovakia [17], and China [12,22,24]), continental (Europe [14] and North America [7,10]), and global [6].…”

“…Taking account of these issues will require carrying out the following tasks in an integrated manner: (1) the long-term SGS and EGS dates should be calculated using a degree-day phenology model that is based on long-term, continuous biometeorological observations [1,16,[32][33][34][35]; (2) the accuracy of the modelled SGS and EGS dates should be assessed by using longterm, continuous phenological images taken at multiple sites [31,36]; and (3) the spatiotemporal distribution of the SGS and EGS dates should be thoroughly evaluated around validation sites by analysing satellite observations with a fine spatial resolution (e.g., 10 m) [31]. In particular, to evaluate the long-term effects of climate change, we need to examine the spatiotemporal variability of SGS and EGS dates for at least the past 120 years, during which continuous observations of temperature have been recorded with modern-day technology.…”

Divergent Response of Leaf Coloring Seasons to Temperature Change in Northern China over the Past 50 Years

“…Some studies argued that the effect of temperature difference between day and night on autumn phenology was underestimated, since temperature difference above 15°C was propitious to color presentation of leaves [20,26]. In addition, minimum temperature was also suggested as an influencing factor of autumn phenology that lower autumn minimum temperature would result in earlier leaf coloring date [27][28][29][30]. Although other environmental factors, such as precipitation, photoperiod, and insolation, would also influence autumn phenology through affecting the formation of leaf abscission meristems and plant carboxylation reaction [31], they were more likely to only constrain the temperature-induced changes.…”