Spatiotemporal Variation And Benefit Of Carbon Cycle Of Farmland Ecosystem In Hebei Province

With the aggravation of global warming effect, in order to decrease the concentrationof greenhouse gases in the atmosphere, research on carbon cycle of farmland ecosystemhas become a hot topic in the field of global change. The farmland ecosystem is an opensystem as an important source and sink of greenhouse gases. On the one hand, theecosystems absorbed a great deal of carbon through photosynthesis impacts and gave outgreenhouse gases through agricultural producing processes and respiration of crops andsoil. The agricultural production of Hebei province has a large proportion in China, but theagriculture of Hebei is producing more and more carbon in recent years with the rapiddevelopment of urbanization, industrialization and the chemical application of agriculture,which results in the unbalance of agricultural ecology. Therefore how to take effectivemeasures to reduce the carbon emission of farmland and make the "win-win" of economicreturns and ecological benefit is becoming an urgent problem in HeBei.In this study, we estimated the size of carbon source, sink and net carbon sink offarmland ecosystems in Hebei province using the statistic data from1989to2010, andanalyzed the temporal and spatial variation of them, and then discussed the factorseffecting carbon sources and sinks of the farmland ecosystems. Finally, we put forwardsome measures to enhance the development of low carbon agriculture based on a SWOTanalysis. The main results are as follows:1) The total carbon absorption and emission of farmland ecosystem in Hebei have agradual rise process in the last22years as a carbon sink, and the intensity of carbon sinkdeclined from southeast to northwest in spaceï¼›2) The carbon absorption of wheat and corn accounted for the largest proportion in themain kinds of crops. Chemical fertilizer application, farm machinery and the irrigationprocesses in the farmland ecosystem emitted a large amount of carbon in which theprocess of chemical fertilizer application accounted for the biggest proportion.3) In the factors of chemical fertilizer application, farm machinery, irrigation input andso on, the chemical fertilizer application has the greatest impact on the gross output valueof agriculture in Hebei province.