| In this paper, the larch plantations of different age groups in north of Yanshan mountain were studied, and various organs CCR of mainly constructive species of the forest tree layer, shrub layer, herb layer, forest ecosystem carbon storage and its spatial distribution characteristics,effcts of different tending for Larch Forests carbon storage was studied,the aim was to understand the carbon sink function of Larch Forests distributed largly in northern of Yanshan Mountain, and build up a scientific basis for the search of carbon cycle in different forest ecosystems of eco-geographical regions of our country, and provild the theoretical guidanc for the management strategiese of carbon sink of forest ecosystem in the conditions of global climate change. The main results are as follows:(1) In Larch Forests, the average carbon rates of the ground organs of 7 tree species were not very different, respectly were 52.86% (larch), 52.78 % (birch), 54.09 % (Populus), 52.80 % (Betula spine) , 50.54 % (Mongolian oak), 49.73% (Acer mono), 51.21% (large leaf linden). Carbon ratios in different organs of four aged stands tree layer species showed leaves were the highest. The average carbon rate of 10 kinds of shrubs organs was 51.23%. The average carbon rate of herbal organs was 48.98%. The average carbon rate of litter was 40.98%.(2) The biomasses of 9 years, 18 years, 33 years and 43 years Larch Forests respectly were: 43.67t/hm2, 67.70t/hm2, 110.38t/hm2, and 281.66t/hm2, in which the proportion of the aboveground sections accounted for 41.25%~74.44%, the proportion of the underground sections were 8.00%~13.34%. In turn, tree layer biomasses were: 28.62t/hm2, 49.76t/hm2, 98.03t/hm2, and 210.50t/hm2. Shrub layer biomasses increased gradually with stand age decreasing, respectively were: 2.50t/hm2, 1.74t/hm2, 1.06t/hm2, and 0.05t/hm2; herb layer biomasses did not show significant variation, followed by 0.17t/hm2, 0.26t/hm2, 1.28t/hm2, and 0.51t/hm2.(3) The total vegetation carbon storages of 4 different ages Larix forests showed a significant increase with stand age increasing, in order: 9 year were 21.97 t/hm2, 18 year 34.14 t/hm2, 33 year 55.62 t / hm2, 43 year 141.70 t/hm2. In the composition of the total carbon storage, tree layer carbon storage occupied the largest proportion, which accounted for 65.8% ~ 88.9%. In addition, litter carbon pool occupied a prominent position in forest total carbon pools, reaching to 9% ~ 28.2%; while forest floor carbon storage were the lowest, only 0.2% ~ 6%. The underground and aboveground part of tree layer carbon storages changed little, but the proportion of branches and leaves carbon storages decreased with age increasing.(4) The biomass conversion and expansion factor BCEF and biomass expansion factor BEF of Larch Forests showed a downward trend with the increase of DBH, the initial declined fastly, when larger than 8cm, the decline has slowed down, in the final the trend became stable; simultaneitily, BCEF, BEF and rhizomes gradually declined with stand age increasing; the BCEF and BEF value of local Larch Forests were close to the average values of China's various regions Larch Forests.(5) In three kinds of thinning intensity, the total loss of forest carbon sinks increased with the stand age increasing, and proportion of carbon loss for the total carbon storage of four aged larch Plantation forest in three kinds of thinning intensity showed the same variation rules, which the percentage of 43 years was the smallest, 9 years and 18 years were inferior, 33 years was the largest.(6) The impacts of three kinds of pruning intensity for 9 years Larch Forest carbon sinks were quite different. In 1m pruning intensity, the loss rate of carbon sinks only was 3% of the overall carbon sink; when in 1.5m pruning intensity, the forest carbon loss increased significantly, was more as high as 2 times than that in 1m pruning intensity, and leaves loss sharply increased; when in 2m pruning intensity, the loss of forest carbon sinks were also certainly increased, but the range of overall loss rate decreased.(7) With stand age increasing, the carbon sink value of Larch Forests increased gradually. According to the average of several methods, in turn as follows: 43 years old (52 300 yuan / hm2)> 33 years old (20 500 yuan / hm2)> 18 years old (12 600 yuan / hm2)> 9 years old (8 100 yuan / hm2).(8) Without considering the soil breath, the values of temporal fixed carbon of 4 aged Larch Forests were quite different, the carbon sink values of 9 years, 18 years, 33 years and 43 years larch respectly were 119.90 yuan / (hm2 ? a), 192.86 yuan / ( hm2 ? a), 903.41 yuan / (hm2 ? a), and 373.63 yuan / (hm2 ? a).
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