Spatiotemporal variation of autumn phenology responses to preseason drought and temperature in alpine and temperate grasslands in China

Zhihui Yuan; Siqin Tong; Gang Bao; Jiquan Chen; Shan Yin; Fei Li; Chula Sa; Yuhai Bao

doi:10.1016/j.scitotenv.2022.160373

Spatiotemporal variation of autumn phenology responses to preseason drought and temperature in alpine and temperate grasslands in China

Sci Total Environ. 2023 Feb 10;859(Pt 2):160373. doi: 10.1016/j.scitotenv.2022.160373. Epub 2022 Nov 19.

Authors

Zhihui Yuan¹, Siqin Tong², Gang Bao³, Jiquan Chen⁴, Shan Yin², Fei Li⁵, Chula Sa², Yuhai Bao⁶

Affiliations

¹ College of Geographical Science, Inner Mongolia Normal University, Hohhot 010022, China; Inner Mongolia Key Laboratory of Remote Sensing and Geographic Information Systems, Inner Mongolia Normal University, Hohhot 010022, China; Department of Natural Resources, Wulanchabu 012000, China.
² College of Geographical Science, Inner Mongolia Normal University, Hohhot 010022, China.
³ College of Geographical Science, Inner Mongolia Normal University, Hohhot 010022, China; Inner Mongolia Key Laboratory of Remote Sensing and Geographic Information Systems, Inner Mongolia Normal University, Hohhot 010022, China. Electronic address: baogang@imnu.edu.cn.
⁴ Department of Geography, Environment, and Spatial Sciences, Michigan State University, East Lansing, MI 48823, USA.
⁵ Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot 010010, China.
⁶ College of Geographical Science, Inner Mongolia Normal University, Hohhot 010022, China; Inner Mongolia Key Laboratory of Remote Sensing and Geographic Information Systems, Inner Mongolia Normal University, Hohhot 010022, China.

PMID: 36414072
DOI: 10.1016/j.scitotenv.2022.160373

Abstract

We investigate the spatiotemporal patterns and environmental controls of the end of the vegetation growing season (EOS) in autumn across the alpine and temperate grasslands of China from 2001 through 2020, focusing on whether the EOS is likely a "dryness effect" due to drought or a "coolness effect" caused by cold temperature in autumn. The results show that the EOS date is earlier (∼6 days earlier on average) in alpine grasslands than in temperate grasslands. During 2001-2020, a slight non-significant delay of 1.0 day/decade is observed for the regional averaged EOS, which is mostly induced by the delayed EOS in 64.4 % of the study region. Preseason temperature (1-2 months before the EOS) exerts a positive control on the EOS in most of the alpine grasslands and some regions of the eastern part of the temperate grasslands, while drought with a mean length of 3.2 months before the EOS exerts positive effects on the EOS in the central, southwestern, and western parts of the temperate grasslands and in the northeastern part of the alpine grasslands. The positive effects of temperature and drought are very likely phenomena reflecting that the EOS is the "coolness effect" associated with lower temperatures in autumn and the "dryness effect" due to drought, especially meteorological drought without consideration of soil moisture, in late summer and/or early autumn, respectively. Our findings are supported by an analysis of the spatial patterns of the cold degree days (CDD) and EOS sensitivity to the CDD. However, the negative effects of drought are also found in eastern temperate grasslands, likely caused by decreased temperature accompanied by increased moisture. The results presented here highlight the importance of incorporating the impacts of droughts on EOS variability, as well as their interactive effects with temperature, into current vegetation autumn phenology models for grasslands.

Keywords: Drought; End of the vegetation growing season; Spatiotemporal pattern; Temperate and alpine grasslands; Temperature.

MeSH terms

China
Climate Change
Droughts*
Ecosystem
Seasons
Soil*
Temperature

Substances

Soil