【作者】 梁关锋；

【导师】 俞元春；

【作者基本信息】 南京林业大学 ， 土壤学， 2011， 硕士

【摘要】 因为大气C02浓度的升高,近来关于土壤有机碳成为关注的热点。在一定程度上,人工林的经营能够改变土壤有机碳库。本文研究试验地位于福建省漳州市九龙岭林场,采用空间代替时间的方法,取条件一致桉树人工林的四个林龄样地1 a,3 a,5 a和7 a,,代表一个轮伐期(7 a)中的四个阶段。分析了土壤有机碳、易氧化态有机碳、化学稳定态有机碳和土壤矿质结合态有机碳,分别用KMnO4、Na2S2O8和HF作为提取剂处理土壤样品。土壤有机碳浓度随土层加深逐渐减少,1 a、3 a、5 a和7 a桉树林地土壤有机碳密度分别为37.67～61.02 Mg·ha-1,57.46～81.97 Mg·ha-1,38.65～73.35 Mg·ha-1和40.68～70.64Mg·ha-1土壤易氧化态有机碳储量随着桉树人工林林龄的增加逐渐增加,但是在各土壤剖面的分布没有显著差异。土壤化学稳定态有机碳的储量随林龄的增加呈现减小的趋势,而矿物结合态有机碳的储量没有显著差异。随着土壤层次的加深,土壤化学稳定态有机碳和矿质结合态有机碳逐渐增加。40-100 cm土层化学稳定态有机碳密度显著大于0-40 cm。在一个轮伐期内,化学稳定态有机碳密度的变化较小,表明化学稳定态有机碳受人工林经营活动的影响小。更多还原

【Abstract】 Soil Organic Carbon (SOC) has been paid great attention recently as it’s contributes to CO2 emission. Forest management, to some extent, could disturb the SOC pool. This research examined forest top 1 m soil after planted in 1 year (1a),3 year (3a),5 year (5a) and 7 year (7a), which generally represented the 4 stages during a rotation period (7 years). The soil was treated after extracted with KMnO4、Na2S2O8、and HF in order to determine the Easily Oxidized Carbon (EOC), Chemical Recalcitrant SOC (Na2S2O8-resist SOC) and Mineral-associated SOC (HF-soluble SOC), respectively. The SOC concentrations decreased with the soil depth increment, and the SOC density were 48.71 Mg ha-1 (±12.22),66.06 Mg ha-1 (±11.28),52.20 Mg ha-1 (±16.33) and 57.66 Mg ha-1 (±13.40) for 1a,3a,5a and 7a, respectively. However, the pool of EOC increased with the forest ages. The Na2S2O8-resist SOC decreased with forest ages and increased with soil increments. The HF-soluble SOC increased with soil increments but showed no significant difference with forest ages. The content of subsoil (40-100 cm) of Na2S2O8-resist SOC was significantly greater than the topsoil (0-40 cm), respectively. The Na2S2O8-resist SOC varied insignificantly during a rotation, it may indicated that the chemical recalcitrant SOC was less affected by the forest management than the mineral-associated SOC.更多还原