地下滴灌对杨树速生丰产林碳储量的影响

Carbon storage in fast-growing and high-yield poplar plantations under subsurface drip irrigation

研究了北京潮白河沿河沙地6年生I-214杨树速生丰产林地下滴灌(SDI)和常规灌溉(NI)条件下的林地碳储量,同时对10年生中林46杨树地下滴灌速生丰产示范林碳汇能力进行了评价。结果表明:1)与常规灌溉相比,地下滴灌能大大增加林地碳储量。2002年(栽植第6年),SDI区乔木层、枯落物层和土壤碳储量分别为25.81、3.53和42.00t/hm2,是NI区的1.27、2.02和1.32倍;SDI区的林地总碳储量76.50t/hm2,比NI区49.61t/hm2增加了54.2%;年净碳增量9.49t/(hm2·a),是NI区5.01t/(hm2·a)的近2倍。2)2010年(栽植第10年),地下滴灌示范林达到了较高固碳水平,乔木层、草本层、枯落物层和土壤碳储量分别为34.71、8.60、8.45和56.20t/hm2,林地总碳储量为107.19t/hm2,年净碳增量达到了8.84t/(hm2·a),比对照区6.25t/(hm2·a)增加了41.4%。建议在干旱半干旱及存在季节性干旱的地区结合当地经济条件推广基于地下滴灌的优化水肥管理技术,大幅度提高杨树速生丰产林林地生产力和碳汇能力,为减缓全球增暖趋势发挥一定的作用。

Carbon storage of six-year poplar I-214（Populus×canadensis cv.＇I-214＇） plantations under subsurface drip irrigation（SDI）,and normal irrigation（NI） at sandy soil in Chaobai River in Beijing was investigated.The carbon sink ability of a ten-year demonstration plantation of poplar Zhonglin-46 was evaluated.The results showed that：1） carbon storage of the plantations under SDI highly increased compared with that under NI.In 2002（6 years after plantation）,the tree storey,litter floor and soil carbon storage under SDI were 25.81,3.53 and 42.00 t/hm2,respectively,and were 1.27,2.02 and 1.32 times of that under NI.The total carbon storage under SDI was 76.50 t/hm2,which was 54.2% more than that under NI of 49.61 t/hm2.The annual net carbon incremental under SDI was 9.49 t/（hm2·a）,approximately 2 times of that under NI of 5.01 t/（hm2·a）.2） In 2010（10 years after plantation）,the demonstration plantation reached a high level of carbon sequestration.The tree storey,under-storey plants,litter floor and soil carbon storage reached 34.71,8.60,8.45 and 56.20 t/hm2,with total carbon storage of 107.19 t/hm2.The annual net carbon incremental reached 8.84 t/（hm2·a）,nearly 41.4% more than control of 6.25 t/（hm2·a）.Therefore,it is suggested to extend the water and fertilizer management technology under subsurface drip irrigation in arid,sub-arid and seasonal arid area according to the local economic conditions since it can not only improve the productivity and carbon sink ability of the fast-growing and high-yield poplar plantations significantly,but also plays a crucial role in slowing down the global warming trend.