Diverse Responses of Vegetation Phenology to Climate Change in Different Grasslands in Inner Mongolia during 2000–2016

Shilong Ren,Matthias Peichl,Xiaoyun Wang,Shuhua Yi

doi:10.3390/rs10010017

Abstract

Vegetation phenology in temperate grasslands is highly sensitive to climate change. However, it is still unclear how the timing of vegetation phenology events (especially for autumn phenology) is altered in response to climate change across different grassland types. In this study, we investigated variations of the growing season start (SOS) and end (EOS), derived from Moderate Resolution Imaging Spectroradiometer (MODIS) data (2000–2016), for meadow steppe, typical steppe, and desert steppe in the Inner Mongolian grassland of Northern China. Using gridded climate data (2000–2015), we further analyzed correlations between SOS/EOS and pre-season average air temperature and total precipitation (defined as 90-day period prior to SOS/EOS, i.e., pre-SOS/EOS) in each grid. The results showed that both SOS and EOS occurred later in desert steppe (day of year (doy) 114 and 312) than in meadow steppe (doy 109 and 305) and typical steppe (doy 111 and 307); namely, desert steppe has a relatively late growing season than meadow steppe and typical steppe. For all three grasslands, SOS was mainly controlled by pre-SOS precipitation with the sensitivity being largest in desert steppe. EOS was closely connected with pre-EOS air temperature in meadow steppe and typical steppe, but more closely related to pre-EOS precipitation in desert steppe. During 2000–2015, SOS in typical steppe and desert steppe has significantly advanced by 2.2 days and 10.6 days due to a significant increase of pre-SOS precipitation. In addition, EOS of desert steppe has also significantly advanced by 6.8 days, likely as a result from the combined effects of elevated preseason temperature and precipitation. Our study highlights the diverse responses in the timing of spring and autumn phenology to preceding temperature and precipitation in different grassland types. Results from this study can help to guide grazing systems and to develop policy frameworks for grasslands protection.

Highlights

Vegetation phenology is the study of periodic biological events in the plant world and their relations with environmental factors, such as air temperature and rainfall [1,2]
Typical steppe, and desert steppe, alone, we found a higher number of pixels showinga asignificantly significantly advancing trend
This study revealed a diverse response of vegetation phenology to climate change in meadow steppe, typical steppe, and desert steppe, which may indicate different succession directions and steppe, typical steppe, and desert steppe, which may indicate different succession directions and spatial spatial patterns of them under the more complex future climate changes

Summary

Introduction

Vegetation phenology is the study of periodic biological events in the plant world and their relations with environmental factors, such as air temperature and rainfall [1,2]. Vegetation spring phenology has attracted a great deal of attention due to its close connection with global change. Understanding of vegetation autumn phenology is limited, though it can play an important role in determining vegetation growing season length and has been found to be significantly affected by climatic change [9]. Ground-observed phenological data and satellite data are two major tools commonly used to identify vegetation growing season at different scales. Ground data are commonly recorded at the species level and used for conducting species-specific phenology analysis at local scales [10,11,12,13]

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