【摘要】 为了探讨亚热带地区倒木分解对土壤C、N的影响,以江西九连山国家自然保护区为研究区域,运用空间代时间的方法,测定不同分解等级下5种倒木(丝栗栲Castanopsis fargesii、米槠Castanopsis carlesii、木荷Schima superba、杉木Cunninghamia lanceolata、马尾松Pinus massoniana)的木质素、纤维素、C、N、密度、含水率以及倒木下土壤的C、N、容重、含水率。结果表明:1)同一分解等级下5种倒木的纤维素、C、N含量差异显著。5种倒木的平均纤维素和C含量在轻度分解等级下分别比在重度分解等级降低了206.3%和28.3%,而平均N含量升高了31.9%。同一分解等级下,常绿阔叶倒木的C、N含量与针叶倒木之间差异显著。在3种(轻、中、重度)分解等级下,常绿阔叶倒木的平均C含量比针叶倒木高16.2%、23.7%和25.3%;平均N含量分别比针叶倒木高12.7%、6.2%和43.5%。2)同一树种倒木下土壤的C、N含量在不同分解等级之间差异显著。5种树种倒木下土壤的平均C、N含量在轻度分解等级下分别比在重度分解等级下高25.8%、35.6%。在3种分解等级下,常绿阔叶倒木下土壤的平均C含量比针叶倒木下土壤显著高了27.0%、21.6%和20.7%;而平均N含量分别比针叶倒木下土壤显著高了21.4%、23.6%和20.8%。3)倒木下土壤C含量与倒木C含量呈显著正相关,系数为0.59,与倒木C/N呈显著负相关,系数为-0.64。倒木下土壤N含量与倒木N含量呈显著正相关,系数为0.52。倒木下土壤含水量与土壤容重呈显著负相关,系数为-0.61。更多还原

【Abstract】 In order to investigate the effects of decomposition of coarse woody debris(CWD) on soil C and N in subtropical regions, the Jiulian Mountain national nature reserve in Jiangxi province was selected as the study area, using space instead of time, and measuring contents of lignin, cellulose, C, N, moisture and density of five CWDs(Castanopsis fargesii, Castanopsis carlesii, Schima superba, Cunninghamia lanceolata, Pinus massoniana) as well as content of soil C, N, moisture and bulk density under five CWDs. The results show that: 1) The cellulose, C and N contents of five CWDs were significantly different undersame decay class, the average cellulose and C contents of five CWDs at the mild decay class decreased by 206.3% and 28.3% respectively for heavy decay class, and the average N contents increased by 31.9%. At the same decay class, the difference between C and N contents of evergreen broad-leaved CWD and coniferous CWD is significant.At the three decay classes of mild, moderate and heavy respectively, the average C contents of evergreen broad-leaved CWD was 16.2%, 23.7% and 25.3% higher than that of coniferous CWD, the average N contents was 12.7%, 6.2%, and 43.5% higher than that of coniferous CWD respectively; 2)The soil C and N contents under five CWDs were significantly different undersame decay class,the average soil C and N contentsunder five CWDs at the mild decay class increased by 25.8% and 35.6% respectively for heavy decay class. At the same decay class, the difference between soil C and N contents under evergreen broad-leaved CWD and coniferous CWD is significant. At the three decay classes of mild, moderate and heavy, the average C contents under evergreen broad-leaved CWD was 27.0%, 21.6% and 20.7% higher than that under coniferous CWD respectively, the average N contents was 21.4%, 23.6%, and 20.8% higher than that under coniferous CWD respectively; 3) There was a significant positive correlation between the soil C contents under CWD and C contents of CWD, with a coefficient of 0.59. But it was a significantly negatively correlated with CWD C/N ratio, with a coefficient of-0.64. There was a significant positive correlation between the soil N contents under CWD and the N contents of CWD, with a coefficient of 0.52. The soil moisture content under CWD was significantly negatively correlated with soil bulk density, with a coefficient of-0.61.更多还原