不同调控措施下橡胶凋落叶分解速率研究

Study on Decomposition of Rubber Leaf-Litter with Different Control Measures

通过原位网袋法,研究6、12、20 a和28 a 4组林龄橡胶凋落叶在不同调控措施下1 a内的分解过程。结果表明：橡胶凋落叶在0.07 mm和1.00 mm孔径网袋内分解趋势基本一致,表现为随时间变化分解呈现先快后慢2个阶段,经1 a分解后,0.07 mm和1.00 mm孔径网袋内残留率分别为36.84%和32.09%。橡胶凋落叶分解速率不仅受埋层位置影响,还与土壤肥力有关。经240 d分解后,地上组（0 cm）和在保留根系下非肥坑地下组（0~30 cm）、肥坑地下组（0~30 cm）残留率分别为32.09%、7.40%和34.58%。土壤肥力对橡胶凋落物分解的影响主要体现在分解中后期,至240 d时,4块林地肥坑和非肥坑平均残留率（保留根系组＋去除根系组平均值）分别为35.62%和8.46%。6、12、20 a和28 a林龄4组橡胶凋落叶原位埋置分解中,前期分解速率差异小,后期分解速率呈显著差异,至240 d时,残留率分别为2.94%、7.05%、14.62%和2.18%。橡胶根系前期促进凋落物分解,后期转为抑制,但橡胶根系没有显著性改变凋落物的分解速率。

Leaf-litter of 6-year-old, 12-year-old,20-year-old and 28-year-old rubber plantations was used to studied the decomposition progress in one year under different control measures by mesh bag method. The results as following ： leaf-litter in 0.07 mm and 1.0 mm mesh bags was in a same decomposition dynamic, which was in- creased first and then drop, and the litter residues rates at the end of year were 36. 84 % and 32. 09 % , respec- tively. Leaf-litter decomposition rates not only by the position of the buried layer influence, but also with soil fertility-related. After 240 d, litter residues of ground plane （0 cm）, comparison hole （0 - 30 era） and fertile hole （0 -30 era） not included roots removed were 32. 09% , 7.40% and 34.58% , respectively. Litter decomposition of rubber was reflected by soil fertility mainly focus on the late stage of decomposition. To 240 d, residues of litter in comparison hole and fertile hole （the average value of the group of roots reserved and roots removed ） were 8.46% and 35.62% , respectively. The difference of litter decomposition rates of 6-year-old, 12-year-old,20-and 28-year-old rubber plantations were little at early stage but significant at late stage. To 240 d, residues of litter were 2.94% , 7.05% , 14.62% and 2. 18% , respectively. Although rubber roots promoted litter decomposition at earlystage, and convert to inhibition at the late stage, no significant influence was detected about rubber roots on litter decomposition at all stages.