Yang Xin Fang, Bao Xue Lian, Hu Guo Qing, Shao Shuai, Zhou Feng, Ye Jia Shu, Xie Hong Tu, Liang Chao
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Ying Yong Sheng Tai Xue Bao. 2016 May;27(5):1359-1367. doi: 10.13287/j.1001-9332.201605.030.
We investigated the fire impacts on nutrients in litter and soil, and their C:N:P stoichio-metry in forests of Great Xing'an Mountains. The studied sites differed in their burning year (post-fire 4, 14, 40, 70 years and unburned within 120 years) and had different topographic locations (sloped land and flat land). The results showed that there were significant differences in stoichio-metry characteristics of C, N, P for both litter and soil with different burning years. No significant fluctuation was observed for the litter C content, while the contents of litter N and P increased with the increasing post-fire recovery years. In specific, we found the contents of litter N and P decreased at post-fire 4 and 14 years and nearly recovered to the control level at 40 years after fire. Additionally, C:N and C:P ratios of litter decreased, but N:P ratio of litter increased following post-fire recovery time. The contents of C, N, P and their ratios (C:N, C:P and N:P) in soil decreased with soil depth. Soil C content exhibited an increasing trend following post-fire recovery time and was significantly higher than the control at post-fire 70 years in sloped land, but no significant difference in the flat land. Significant interactive effects between fire history and slope were observed in soil P content and C:P ratio. Soil P content was higher than the control at post-fire 4 years in sloped land, but was higher than the control at post-fire 40 years in flat land. The C:P ratio recovered to the control level at post-fire 14 years in sloped land, and there was no significant diffe-rence in flat land. Redundancy analysis showed that slope effect played a more vital role than fire history effect in soil organic layer, while fire history effect was the most important factor for the varia-tion of soil nutrients in soil mineral layer. In our study, nutrients of litter and soil were lower than the control level at post-fire 4 and 14 years. The quality of litter and soil was improved with accele-rated plant growth and litter decomposition following post-fire recovery time and recovered to the pre-fire level at post-fire 40 years, reaching a steady status.
我们研究了大兴安岭森林火灾对凋落物和土壤养分及其碳氮磷化学计量特征的影响。研究地点的火灾年份不同（火灾后4年、14年、40年、70年以及120年内未发生火灾），且地形位置不同（坡地和平地）。结果表明，不同火灾年份的凋落物和土壤的碳、氮、磷化学计量特征存在显著差异。凋落物碳含量未观察到显著波动，而凋落物氮和磷含量随火灾后恢复年限的增加而增加。具体而言，我们发现火灾后4年和14年凋落物氮和磷含量下降，火灾后40年几乎恢复到对照水平。此外，凋落物的碳氮比和碳磷比下降，但凋落物的氮磷比随火灾后恢复时间增加。土壤中碳、氮、磷含量及其比例（碳氮比、碳磷比和氮磷比）随土壤深度降低。土壤碳含量随火灾后恢复时间呈增加趋势，坡地在火灾后70年显著高于对照，但平地无显著差异。在土壤磷含量和碳磷比方面，观察到火灾历史和坡度之间存在显著的交互作用。坡地在火灾后4年土壤磷含量高于对照，而平地在火灾后40年高于对照。坡地在火灾后14年碳磷比恢复到对照水平，平地无显著差异。冗余分析表明，坡度效应在土壤有机层中比火灾历史效应发挥更重要的作用，而火灾历史效应是土壤矿质层土壤养分变化的最重要因素。在我们的研究中，火灾后4年和14年凋落物和土壤养分低于对照水平。随着火灾后恢复时间的推移，植物生长加快和凋落物分解，凋落物和土壤质量得到改善，火灾后40年恢复到火灾前水平，达到稳定状态。
