Temporospatial variation analysis on carbon source/sink of farmland ecosystem in Guangdong

On the base of the statistical data of crop output, crop sewn area, planting area and agricultural input in 21 zones of Guangdong during 1992 to 2011, this paper estimated carbon source and sink of Guangdong farmland ecosystem and studied the influente factors of carbon source and sink of farmland ecosystem. The results indicated that the total amount of carbon absorption in Guangdong farmland ecosystem presented a gradual decline during the two decades. The amount of carbon absorption of vegetables and fruits increased obviously. The total amount of carbon emission gradually increased, among which the amount of carbon emission caused by such agricultural chemicals as fertilizer, pesticide took the highest percentage. The amount of carbon emission was far less than that of carbon absorption in Guangdong farmland ecosystem. Crops had strong carbon absorbing function, represented obvious carbon sink. From the aspect of distribution pattern, the amount of carbon emission and carbon absorption diversed among various parts of Guangdong.