Carbon Sequestration And Sink Enhancement Technologyes Of Several Kinds Of Poplar Plantations In The North Of China

The poplar plantation in the north of China was studied in this research. This study was investigated in four regions of the mainly poplar planting area which was Shandong Yellow River flood plain, Shunyi, Daxing and Tongzhou of Beijing. According to the different areas of the site conditions, varieties of poplar and economic status, the poplar were taken different models. The carbon storage distribution of several parts of poplar planations forest ecosystem were investigated under different technologyes. The study concluded the optimization solid increasing carbon sink technologyes of the four different planting areas. The main conclusions are as follows.1、In the four-year triploid Populus tomentosa pulpwood in the Yellow River Flood Plain of Shandong, each part of the carbon storage of D1(wide and narrow row+subsurface drip irrigation with water, fertilizer+intercropping cotton and wheat), D2(wide and narrow row+irrigation+alfalfa intercrop) was better than CK (uniform spacing+irrigation+intercropping cotton). The tree carbon of D1, D2was53.7%and7.9%more than that under CK. The crop carbon storage were were1.86and2.50times of that under CK. Compared with the early plantation, the soil net carbon incremental increase18.4%-31.8%. The annual carbon sequestration capacity were14.00and16.07t/(hm2·a), which were much higher than that under CK of9.39t/(hm2·a). Synthesis the advantage of D1and D2.We received the solid carbon sink enhancement technology of this erea, which was the wide and narrow row spacing of underground drip irrigation fertilization and alfalfa intercropping technology.2、Carbon storage of six-year poplar1-214(Populus×canadensis cv.’1-214’) plantations under subsurface drip irrigation (SDI), and normal irrigation(NI) at sandy soil in Chaobai River in Beijing was investigated. Carbon storage of the plantations under SDI highly increased compared with that under NI. The tree storey, litter floor and soil carbon storage under SDI were were1.27,2.02and1.32times of that under NI. The annual net carbon incremental under SDI was9.49t/(hm2·a), approximately2times of that under NI of5.01t/(hm2-a). Therefore, in seasonally dry areas, subsurface drip irrigation is the optimization technology to improve the poplar plantation carbon sequestration.3、In the nine-year protection poplar plantation in Daxing of Beijing,the carbon storage of stump grafting plantation was greatly more than reforestation plantation. The tree storey, under-storey plants, litter floor and soil carbon storage of stump grafting plantation were were2.61,4.05,3.07and1.07times of that of reforestation plantation. The annual net carbon incremental was10.04t/(hm2-a), respectively, were2.66and1.18times more than the same underground and aboveground reforestation forest. Therefore, stump grafting technique is the optimization carbon sink enhancement technology in the renewal of aging inefficient protection poplar plantation in Daxing District.4、In the four-year Populus×euramericana cv."74/76" timber plantation in Tongzhou of Beijing, different conventional techniques (urea, slow-release fertilizer, compound fertilizer and intercropping nitrogen fixing plant Medicago sativa) were used in4quarters respectively. After treatment, the ecosystem carbon storage of four districts were no significant difference, but each had its own advantages compared with the contrast. The ecosystem carbon storage of4quarters were64.31-73.75t/hm2, The annual net carbon incremental was10.12-14.84t/(hm2-a), respectively, were0.60-1.34times more than CK of6.33t/hm2. Therefore, the four conventional techniques all were optimization carbon sink enhancement technologyes in this planting erea.we can choose them according to the actual situation..