不同经营方式对杉木林采伐迹地土壤C储量的影响

Effects of Different Management Patterns on Soil Carbon Storage of the Deforested Lands in Chinese Fir Plantation

多年定位观测的数据对比分析结果表明:湖南会同22年生杉木林采伐前,林地土壤(0～60cm)层中的C储量为160.38t·hm-2,100%皆伐后一年林地土壤(0～60cm)层中的C储量损失率为35.00%,二年后损失率为44.65%,三年后损失率为43.93%;与对照林林地土壤相比,50%间伐和100%皆伐后三年,林地土壤(0～60cm)层中的C储量损失率分别为16.14%和45.15%;4种不同经营方式的采伐迹地土壤(0～60cm)层中的C储量有明显的差异,大小次序为:已郁闭杉木林林地(108.20t·hm-2)>农用后撂荒地(92.68t·hm-2)>经济林栽培地(85.80t·hm-2)>自然更新采伐迹地(80.29t·hm-2).未烧地土壤(0～45cm)层中C储量为73.36t·hm-2,比火烧地高出了15.20t·hm-2,火烧后40天内林地土壤(0～45cm)层中C储量的损失率为20.7%;杉木林地土壤表层(0～15cm)的C含量明显高于其它层次,其C储量占土壤(0～60cm)层C储量的30.04%,土壤(0～30cm)层中的C储量占53.52%.

Based on the data collected from located observation in successive years, comparative analyses were made in Chinese fir plantation at Huitong, Hunan. Results show that before deforestation, carbon storage of forest-land soil (0～60 cm) amounts to 160.38 t.hm^(-2) in the 22-year-old Chinese fir plantation; that one year after 100% of clear cut, carbon storage in the deforested-land soil (0～60 cm) loses 35.00%, two years, 44.65% and three years, 43.93%; that compared with the control standing forest, three years after 50% of thinning and 100% of clear cut, carbon storage in the deforested-land soil (0～60 cm) loses 16.14%,and 45.15% respectively; and that carbon storage in the deforested-land soil (0～60 cm) indicates evidently the diversity with different management patterns. Results also show that four kinds of management patterns go from high storage to low in the following order: the closed Chinese fir forest-lands (108.20 t·hm^(-2))>the fallow-lands after farming (92.68 t·hm^(-2))>the economic forest-lands (85.80t·hm^(-2))>the natural regeneration deforested-lands; that carbon storage in the non-fired land soil (0～45 cm) is up to 73.36 t·hm^(-2) which is 15.20 t·hm^(-2) higher than that in the fired land soil; that carbon storage in the fired land soil (0～45 cm) loses (20.7%) 40 days after firing; and that carbon storage in the surface soil (0～15 cm) is higher than that in other soil layer, which amounts to 30.04% of the total carbon storage in soil (0～60 cm), and that in the soil (0～30 cm) is 53.52%.