Using MODIS LAI Data to Monitor Spatio-Temporal Changes of Winter Wheat Phenology in Response to Climate Warming

Yang Song,Jianxi Huang,Qiang Yu,Jing Wang

doi:10.3390/rs12050786

Abstract

Understanding spatio-temporal changes in winter wheat (Triticum aestivum L) phenology and its response to temperature will be vital for adapting to climate change in the coming years. For this purpose, the heading date (HD), maturity date (MD), and length of the reproductive growth period (LRGP) were detected from the remotely sensed leaf area index (LAI) data by a threshold-based method during the harvest year 2003 to 2018 across the North China Plain. The results show that there was high spatial heterogeneity of winter wheat phenology in pixel scale across the whole area, which could not be detected in previous site-based studies. The results also verified that climate warming could explain part of the change in the HD. However, for the LRGP, the potential impact of non-climate effects should be further investigated. This study presents the spatio-temporal changes both in winter wheat phenology and corresponding mean temperature and then analyzes their relationships in pixel scale. Additionally, this study further discusses the potential impact of non-climate effects on the LRGP.

Highlights

Over the past several decades, the annual mean of daily mean temperatures in the North China Plain (NCP) has experienced an increasing trend of approximately 0.2 ◦C per decade [1,2]
The heading date (HD) and maturity date (MD) increased from the south to the north, but the length of the reproductive growth period (LRGP) had a relatively stable length of about 40 to 45 days
Based on the four-day composite leaf area index (LAI) product, the spatio-temporal changes in satellite-based winter wheat phenology were derived with more detail

Summary

Introduction

Over the past several decades, the annual mean of daily mean temperatures in the North China Plain (NCP) has experienced an increasing trend of approximately 0.2 ◦C per decade [1,2]. Climate change has influenced the terrestrial ecosystems [1,2,3,4,5]. A warmer growth environment could further affect the vegetation and the whole ecosystem. Phenological shifts can be an important indicator for us to better understand some of the changes to ecosystems [6,7,8,9]. For native and perennial plant species, increasing spring temperatures could generally boost vegetation growth, lengthen the growing season, and enhance the net ecosystem productivity [10,11,12]. For the winter wheat in the NCP, a warmer climate could accelerate senescence, shorten the growing period, and lead to yield loss [13,14,15,16,17]

Objectives

Methods

Results

Discussion

Conclusion