Li Ren-Hong, Hu Ting-Xing, Tu Li-Hua, Luo Shou-Hua, Xiang Yuan-Bin, Dai Hong-Zhong, Huang Li-Hua
Sichuan Provincial Key Laboratory of Forestry Ecological Engineering, College of Forestry, Sichuan Agricultural University, Ya'an 625014, Sichuan, China.
Ying Yong Sheng Tai Xue Bao. 2009 Nov;20(11):2588-93.
An in situ experiment was conducted to study the effects of simulated nitrogen deposition on the litter decomposition in Neosinocalamus affinis stands in rainy area of West China. Four treatments were installed, i.e., null N (CK, 0 kg x hm(-2) x a(-1)), low N (LN, 50 kg x hm(-2) x a(-1)), medium N (MN, 150 kg x hm(-2) x a(-1)), and high N (HN, 300 kg x hm(-2) x a(-1)). Among the litters, leaf had the highest decomposition rate, followed by sheath, and twig, with a remaining rate after decomposing for 15 months being 26.38%, 46.18%, and 54.54%, respectively (P < 0.01). Leaf litter decomposed faster during the first 2 months and the 7th-10th month, while the decomposition of sheath and twig was faster from the 5th to the 8th month. It took 2.573 years to decompose 95% of leaf litter mass, 1.686 years and 3.319 years shorter than that of sheath and twig, respectively. After 15 months decomposition of leaf litter, no significant differences were observed among different treatments. To decompose 95% of sheath litter needed 2.679-4.259 years, being the longest in CK and the shortest in treatment MN. After decomposing for 15 months, the decomposition rate of twig litter was in the order MN > HN > LN > CK, and significant difference existed between treatments MN and LN. Nitrogen deposition had obvious promotion effect on the litter decomposition in the N. affinis stands, but this effect decreased with increasing deposited N concentration and time extension.
在中国西部多雨地区，开展了一项原位实验，以研究模拟氮沉降对慈竹林凋落物分解的影响。设置了4种处理，即不施氮（CK，0 kg·hm⁻²·a⁻¹）、低氮（LN，50 kg·hm⁻²·a⁻¹）、中氮（MN，150 kg·hm⁻²·a⁻¹）和高氮（HN，300 kg·hm⁻²·a⁻¹）。在凋落物中，叶片的分解速率最高，其次是叶鞘，然后是小枝，分解15个月后的残留率分别为26.38%、46.18%和54.54%（P<0.01）。叶片凋落物在前2个月和第7至10个月分解较快，而叶鞘和小枝在第5至8个月分解较快。分解95%的叶片凋落物质量需要2.573年，分别比叶鞘和小枝短1.686年和3.319年。叶片凋落物分解15个月后，不同处理间未观察到显著差异。分解95%的叶鞘凋落物需要2.679 - 4.259年，在CK处理中最长，在MN处理中最短。分解15个月后，小枝凋落物的分解速率顺序为MN > HN > LN > CK，MN和LN处理间存在显著差异。氮沉降对慈竹林凋落物分解有明显促进作用，但这种作用随施氮浓度增加和时间延长而降低。
