DOI: 10.5061/dryad.fn2z34v3d
title: Drought shortens subtropical understory growing season by advancing leaf senescence

description: Subtropical forests, recognized for their intricate vertical canopy
 stratification, exhibit high resistance to extreme drought. However, the
 response of leaf phenology to drought in the species-rich understory
 remains poorly understood. In this study, we constructed a digital camera
 system, amassing over 360,000 images through a 70% throughfall exclusion
 experiment, to explore the drought response of understory leaf phenology.
 The results revealed a significant advancement in understory leaf
 senescence phenology under drought, with 11.75 and 15.76 days for the
 start and end of the leaf-falling event, respectively. Pre-season
 temperature primarily regulated leaf development phenology, whereas soil
 water dominated the variability in leaf senescence phenology. Under
 drought conditions, temperature sensitivities for the end of leaf
 emergence decreased from -13.72 days ℃-1 to -11.06 days ℃-1, with
 insignificance observed for the start of leaf emergence. Consequently,
 drought treatment shortened both the length of the growing season (15.69
 days) and the peak-growth season (9.80 days) for understory plants.
 Moreover, this study identified diverse responses among intra- and
 inter-species to drought, particularly during the leaf development phase.
 These findings underscore the pivotal role of water availability in
 shaping understory phenology patterns, especially in subtropical forests.
description: We constructed a digital camera system to monitor understory leaf
 phenology within a throughfall exclusion experiment in a subtropical
 forest. The start of leaf emergence, end of leaf emergence, start of leaf
 falling, and end of leaf falling of understory were extracted.
 Subsequently, The length of growing season and length of peak growth were
 calculated. Simultaneously, pertinent climatic variables were recorded.
 Additional methodological details can be found in the “Materials and
 methods” section of the article.
description: # Drought shortens subtropical understory growing season by advancing leaf
 senescence
 [https://doi.org/10.5061/dryad.fn2z34v3d](https://doi.org/10.5061/dryad.fn2z34v3d) We utilized a digital camera system in conjunction with a throughfall exclusion experiment to examine the impact of drought on subtropical understory leaf phenology. Our findings revealed a notable advancement in understory leaf senescence phenology, with an insignificant shift observed in leaf development phenology under experimental drought conditions, ultimately leading to a shortened growing season. ## Description of the data and file structure Table 1. Daily understory normalized GCC (Green Chromatic Coordinates) in the throughfall exclusion experiment at plot-scale from 2017 to 2022 Table 2. Daily understory normalized GCC in the throughfall exclusion experiment at species-scale Table 3. Understory leaf phenology in the throughfall exclusion experiment at plot-scale from 2017 to 2022 Table 4. The leaf phenology of dominant understory species in the throughfall exclusion experiment Table 5. Climatic and biotic factors influencing understory leaf phenology Table 6. Leaf eco-physiological traits of dominant seedlings and shrub species measured at this study site Table 7. DBH (diameter at breast height) of seedling and shrub, and crown diameter of fern in the throughfall exclusion experiment ## Abbreviations Green Chromatic Coordinates: GCC Start of leaf emergence: SOLE End of leaf emergence: EOLE Start of leaf falling: SOLF End of leaf falling: EOLF Length of growing season: LOGS Length of peak growth: LOPG Photosynthesis rate: A Stomatal conductance: gs Intrinsic water use efficiency: iWUE Diameter at breast height: DBH ## Sharing/Access information More infromation about the dataset, please contact Huanfa Sun (Email: [hfsun@stu.ecnu.edu.cn](mailto:hfsun@stu.ecnu.edu.cn)).