Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New estimates on carbon emissions triggered by 300 years of cropland expansion in Northeast China

30.09.2014

The conversion of forests, grasslands, shrublands and wetlands to cropland over the course of three centuries profoundly changed the surface of the Earth and the carbon cycle of the terrestrial ecosystem in Northeast China.

In a new study published in the Beijing-based journal SCIENCE CHINA Earth Sciences, a team of researchers from Beijing Normal University, Nanjing University of Information Science & Technology, and the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences, present new calculations on carbon emissions triggered by the expansion of cropland in this region between 1680 and 1980.


The image on the left depicts a reconstruction of pre-agriculture land cover, and the chart on the right shows carbon emissions from forest, grassland, wetland, and shrubland.

Credit: ©Science China Press

"Using regional land cover reconstructions from historical records, with a bookkeeping model, we estimated the carbon sink changes caused by historical cropland expansion in Northeast China during the past 300 years," state researchers Li Beibei, Fang Xiuqi, Ye Yu and Zhang Xuezhen.

In a new study titled, "Carbon emissions induced by cropland expansion in Northeast China during the past 300 years," these researchers state that during the three centuries until 1980, approximately 38% of the grassland and 20% of the forest and shrubland were converted to cropland.

"The carbon emission induced by cropland expansion between 1683 and 1980 was 1.06–2.55 Gt C(gigaton of carbon)," they state..

"The primary source of carbon emissions was forest reclamation (taking 60% of the total emissions in the moderate scenario), the secondary source was grassland cultivation (taking 27%), and the tertiary sources were shrubland and wetland reclamation (taking 13%)," they add.

"The carbon emission estimation in this study was lower than those in previous studies," they explain, "because of the improved land use data quality and various types of land use change considered."

These researchers reconstructed land cover during the period 1680-1980 by consulting historical documents including government files, Russian investigations in Northeast China, documents of the Manchurian Railway, and official statistics.

Both deforestation and grasslands reclamation for agricultural development has triggered large carbon emissions into the atmosphere. Land cover across Northeast China experienced dramatic changes during that period because of large-scale migration and agricultural development.

After Manchu warriors seized control of Beijing in 1644, they established the Qing Dynasty but closed off their homeland in northern Manchuria to migration by common Han Chinese citizens.

"The Qing Dynasty government then changed its policy from prohibiting to encouraging Han's migration for agriculture in the second half of the 19th century," state the researchers.

“The Hans’ migration and subsequent land reclamations resulted in a rapid increase of carbon emissions to 0.197 Gt C in 1850–1899, 0.758 Gt C in 1900–1949, and 0.371 Gt C in 1950–1980,” they explain.

From 1683 to 1980, between 35.5×103 and 97.4×103 square kilometers of forest were converted into cropland, along with 93.4×103 to 94.7×103 square kilometers of grassland, 23.1×103 to 61.8×103 square kilometers of shrubland, and 10×103 to 11.1×103 square kilometers of wetland.

Migration and the conversion of forests and grasslands into cultivated land proceeded northward, through what are now called Liaoning Province, Jilin Province, and Heilongjiang Province, from the end of the 1800s onward.

"Since 1900," the co-authors of the new study explain, "carbon emissions from Heilongjiang Province have greatly increased and even exceeded the total emissions of the other two provinces."

"During the 20th century," they add, "the largest increase in cropland occurred in Heilongjiang Province."

The co-authors of the new paper also explain that while previous studies focused mainly on carbon emissions from land use changes in terms of forest ecosystems, their research found that the conversion of non-forest ecosystems likewise played an important role in developing cropland and triggering carbon emissions.

"The carbon loss per unit area of the forest reclamation was larger than that in other, non-forest ecosystems, which caused the estimation in this study to be lower than Houghton et al.'s (2003) and Ge et al.'s (2008a) estimates," they state.

"The estimates of emissions from this study were lower than those from Houghton et al. (2003) and Ge et al. (2008a)," they add, "because this study used higher spatial resolution land use data based on historical documents and included disturbances of non-forest ecosystems such as steppe, shrub, and swamp."

###

This work was supported by the China Global Change Research Program (Grant No. 2010CB950103), the National Natural Science Foundation of China (Grant Nos. 40901099, 40571165), the Fundamental Research Funds for the Central Universities (Grant No. 2009SAP-2), and the Scientific Research Funds of Nanjing University of Information Science & Technology (Grant No. S8112090001).

See the article:

Li B B, Fang X Q, Ye Y, et al. 2014. Carbon emissions induced by cropland expansion in Northeast China during the past 300 years. SCIENCE CHINA: Earth Sciences, 57: 2259–2268, doi: 10.1007/s11430-014-4894-4

http://earth.scichina.com:8080/sciDe/EN/abstract/abstract515324.shtml

http://link.springer.com/article/10.1007%2Fs11430-014-4894-4

SCIENCE CHINA Earth Sciences is produced by Science China Press, a leading publisher of scientific journals in China that operates under the auspices of the Chinese Academy of Sciences. Science China Press presents to the world leading-edge advances made by Chinese scientists across a spectrum of fields. http://www.scichina.com/english/

Fang Xiuqi | Eurek Alert!

More articles from Ecology, The Environment and Conservation:

nachricht Global threat to primates concerns us all
19.01.2017 | Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung

nachricht Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>