Grassland Productivity Response to Climate Change in the Hulunbuir Steppes of China

Zhang Zhang,Li Li

doi:10.3390/su11236760

Abstract

As global climate change deeply affects terrestrial ecosystem carbon cycle, it is necessary to understand how grasslands respond to climate change. In this study, we examined the role of climate change on net primary productivity (NPP) from 1961 to 2010 in the Hulunbuir grasslands of China, using a calibrated process-based biogeochemistry model. The results indicated that: Temperature experienced a rise trend from 1961; summer and autumn precipitation showed a rise trend before the 1990s and decline trend after the 1990s. Winter and spring precipitation showed an ascending trend. Simulated NPP had a high inter-annual variability during the study period, ranging from 139 g Cm−2 to 348 g Cm−2. The annual mean NPP was significant and positive in correlation with the annual variation of precipitation, and the trend was first raised then fell with the turn point at the 1990s. Temperature had a 20–30 d lag in summer, but none in spring and autumn; precipitation had a 10–20 d lag in summer. The climate lag effect analysis confirmed that temperature had a positive effect on NPP in spring and a negative effect in summer.

Highlights

In response to anthropology causing rapidly rising concentrations of atmospheric greenhouse gases, the mean global temperature has increased continuously since the 1850s, with even higher rates after the 1950s [1]
Our aim is to: (1) Calibrate and localize the Biome-BGC model used in Hulunbuir grassland community based on field surveyed biomass data and remote sensing derived net primary productivity (NPP); (2) investigate the evidence of NPP change and trends of typical grasslands under five decades of climate change; and (3) assess how climate change affects grasslands by determining the relationship between grassland growth and climate variables
This area has a continental climate of the mid-latitude zone in the Mongolia plateau region, and local semiarid climate is deeply impacted by Siberian Mongolia cold and dry air [28]

Summary

Introduction

In response to anthropology causing rapidly rising concentrations of atmospheric greenhouse gases, the mean global temperature has increased continuously since the 1850s, with even higher rates after the 1950s [1]. Since warming leads to an increased risk of drought in summer, but more precipitation occurs with rain instead of snow and snow melts earlier in spring [2,3]. These changes have pronounced impacts on terrestrial ecosystems [4], and the response of terrestrial ecosystems to climate change has been a major research issue of global change [5]. Previous work has found that significant climate change over the past 50 years in temperate grasslands in China has certainly affected the plant productivity and the carbon budget of this region [9]. Due to their complexity and diversity, the grasslands of Hulunbuir belonging to the middle latitude area, located in northeastern China, appear to be more sensitive to climate change, making this ecosystem uniquely suitable for studies of the effect of climate change on productivity

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