Continued Hydrothermal and Radiative Pressure on Changed Cropland in China

Yiming Fu,Yaochen Qin,Haoming Xia,Nan Li,Yaoping Cui,Liangyu Chen

doi:10.3390/su11143762

Abstract

Both cropland and climate change over time, but the potential effects of climate change on cropland is currently not well understood. Here, we combined temporally and spatially explicit dynamics of cropland with air temperature, precipitation, and solar radiation datasets. China’s cropland showed a clear northward-shifting trend from 1990 to 2015. The cropland decreased south of the break line at 38° N, whereas it increased from the break line to northern regions. Correspondingly, the temperature showed a significant warming trend in the early part of the study period, which slowed down in later years. During the whole study period, both precipitation and solar radiation decreased over time, showed no significant linear characteristics, and the annual fluctuations were very large. The cropland areas in China showed a displacement characteristic with the increasing temperature, precipitation, and radiation. Overall, the cropland was shifting towards the high-temperature, low-precipitation, and low-radiation areas. The cropland dynamics indicate that they are likely to face severe drought and radiation pressure. Our findings imply that more resources such as irrigation may be needed for cropland, which will undoubtedly aggravate the agricultural water use in most northern regions, and the potential impacts on food security will further emerge in the future.

Highlights

The supply of cropland directly affects China’s food security and has received considerable research attention [1,2]
In the context of global change, systematic analysis of cropland dynamics and their corresponding changes in key climate conditions such as hydrothermal and solar radiation conditions are important for understanding cropland resources, assessing the supply of resources needed for farming, and ensuring food production safety [3,4]
In view of the various impacts faced by cropland, the government has proposed to adhere to a cropland area of 1.2 million km2 across China to ensure the bottom line of food security

Summary

Introduction

The supply of cropland directly affects China’s food security and has received considerable research attention [1,2]. The changes of China’s cropland and the factors driving this change have been analyzed [5,6,7]. A series of ecological engineering measures, such as returning cropland to forest and grassland, have led to the loss of cropland [9,10]. In view of the various impacts faced by cropland, the government has proposed to adhere to a cropland area of 1.2 million km across China to ensure the bottom line of food security. The government has introduced a series of measures such as “balance of occupation and compensation for cropland” and “basic farmland protection” to limit the loss of cropland resources [12]

Methods

Results

Discussion

Conclusion