scholarly journals Analysis on the Spatio-Temporal Evolution and Influencing Factors of China's Grain Production

Author(s):  
Shaoting Li ◽  
Daojun Zhang ◽  
Yuan Xie ◽  
Chao Yang

Abstract The rapid economic development and climate change have accelerated the changes in China's food production and have a potential impact on food security. In this paper, the grain sown area from 2001 to 2019 was selected to analyze the spatio-temporal evolution and driving factors of China's grain production through spatial autocorrelation analysis and geographically weighted regression. Our findings were as follows: (1) From the perspective of time characteristics, China's grain production from 2001 to 2019 experienced four stages: rapid decline, rapid growth, steady growth, and slow decline, although with an overall upward trend. (2) From the perspective of spatial characteristics, the overall spatial pattern had a significant positive correlation. The high values were mainly concentrated in Shandong, Anhui and Jilin, and moved to the northeast China as time went on. (3) In terms of influencing factors, the positive impact of agricultural labor force on the grain production gradually decreased, showing a decreasing trend from southwest to northeast. The promotion of agricultural mechanization on the grain production increased year by year, with the spatial distribution characteristics of high in the northeast and low in the southwest. Besides, the coefficient of water resources endowment was negative, showing a spatial distribution pattern of high north and low south.

2021 ◽  
Vol 36 (5) ◽  
pp. 1224
Author(s):  
Fan LI ◽  
Wen-li QIANG ◽  
Xiao-jie LIU ◽  
Shu-wen NIU ◽  
Qin-yao ZHU ◽  
...  

2021 ◽  
Vol 234 ◽  
pp. 00081
Author(s):  
Ouassila Riouchi ◽  
Faid El Madani ◽  
Eric Abadie ◽  
Ali Skalli ◽  
Mourad Baghour

This work aims to study the spatio-temporal evolution of the genus Nitzschia longissima, one of the most important genera of marine plankton diatoms, from 3 sampling stations in the Nador lagoon and during 2 seasons (spring and summer 2018), Using Nitzschia longissima, as a study system, one of the most diverse and abundant genera among marine planktonic diatoms. This species counts, in addition to the form Nitzschia longissima forma parva Grunow, three varieties namely Nitzschia longissima var. closterium (W. Smith) Van Heurck, Nitzschia longissima var. longissima (Breb.) Ralfs and Nitzschia longissima var. reversa Grunow. Nitzschia Longissima genus density was high during the warm season (Summer 2018) with a value of 8000 cells/liter, and low during the cold seasons (Spring 2018), which may be caused by water temperature and zooplankton community structure; and underwater light intensity was an important factor influencing the spatial distribution of Nitzschia density.


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