Legacy effects of spring phenology on vegetation growth under preseason meteorological drought in the Northern Hemisphere

Uniforming spring phenology under non-uniform climate warming across latitude in China.

Agroclimatic requirements and phenological responses to climate change of local apple cultivars in northwestern Spain

Climate warming has advanced the spring phenology of many plant species by accelerating heat accumulation. However, delayed phenophases due to insufficient chilling have also been reported. Based on phenological observation data (1963–2010), we compared the effects of preseason chill and heat accumulation on leaf unfolding dates of four deciduous woody species (Lagerstroemia indica, Robinia pseudoacacia, Sophora japonica, and Ulmus pumila) in temperate and subtropical regions of China. Daily chill and heat accumulation were calculated by two chilling models (the Positive Utah Model and the Dynamic Model) and the Growing Degree Hour (GDH) Model. We determined the temporal trends in chill and heat accumulations for leaf unfolding of the four species. The results showed that there were shorter chilling periods in the subtropics than in temperate sites because the chilling period typically started later and ended earlier. There was no significant difference in the length of the forcing period in the different regions. The chilling requirements for leaf unfolding were higher in temperate regions (1344.9–1798.9 chilling units (CU) or 64.7–79.4 chilling portions (CP)) than in the subtropics (1145.9–1828.1 CU or 47.9–75.2 CP). Plants in the subtropics needed higher forcing temperatures (4135.8–10084.8 GDH) than those in temperate regions (3292.0–8383.6 GDH). The earlier-leafing species (e.g., U. pumila) had a lower heat requirement for leaf unfolding than the later-leafing species (e.g., L. indica). A significant increase in heat accumulation was found at all sites except Guiyang, while chill accumulation only increased in Beijing.

Comparison of chilling and heat requirements for leaf unfolding in deciduous woody species in temperate and subtropical China

Land surface phenology detections from multi-source remote sensing indices capturing canopy photosynthesis phenology across major land cover types in the Northern Hemisphere

Liang Guo

Papers

Effects of winter chilling vs. spring forcing on the spring phenology of trees in a cold region and a warmer reference region.