Abstract: Aimed to understand the carbon storage of poplar-crop ecosystem in Eastern Henan Plain, the poplar-crop ecosystems with different ages (5, 9, 11, and 13 years old) of poplar were selected, and each of them was further divided into four subsystems, i.e., forest, crop, litterfall, and soil. In the poplar-crop ecosystems with 5, 9, 11, and 13 years old poplar, the carbon storage of the subsystems forest and litterfall was summed as 7.86, 42.07, 44.31, and 60.71 t·hm^-2, respectively. Subsystem crop averagely sequestrated 6.8 t·hm^-2 of CO₂ per year, and the carbon storage of subsystem soil chieved 45.55, 51.06, 55.94, and 60.49 t·hm^-2, respectively. The total carbon storage of these four poplar-crop ecosystems reached 60.81, 100.09, 106.76, and 127.34 t·hm^-2, respectively, much higher than that in mono-cultured farmland (49.36 t·hm^-2). For the test poplar-crop ecosystems, the carbon storage of subsystems forest and soil occupied a large proportion, accounting for 87.1%-93.1% of the total carbon storage, while that of subsystems crop and litterfall occupied a relatively small proportion, being 6.9%-12.9% of the total, illustrating that agroforestry ecosystem had a high potential in carbon absorption and sequestration.

Key words: agro-forestry ecosystem, poplar-crop, carbon storage, Eastern Henan Plain, cold-waterlogged paddy field, soil property, soil quality assessment, assessment factor, minimum data set, multivarate statistics.