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通过湖南会同杉木人工林3个试验地点的林下植被去除试验,研究了林下植被剔除对凋落物分解的影响.结果表明:杉木人工林未分解凋落层、半分解层和已分解层的凋落物现存量分别为(123.7±46.3)、(204.2±79.1)和(187.1±94.8)g·m-2,相应的C浓度为(447.51±16.75)、(418.89±35.75)和(376.11±47.33)g·kg-1,N浓度为(4.87±1.24)、(6.4±2.38)和(4.66±2.64)g·kg-1,P浓度为(0.14±0.01)、(0.16±0.03)和(0.16±0.02)g·kg-1.在试验点DL87和MS90中,林下植被剔除对半分解层凋落物的现存量和养分储量有显著影响,且不同试验地点的结果不一致,DL87的C、N、P储量降低55%以上,而MS90则上升约1倍,但对未分解层和已分解层的现存量和养分储量基本没有影响.林下植被剔除对凋落物分解早期阶段没有显著影响,处理150d后则有明显的抑制效应,剔除组分解速率下降了20.8%.因此,林下植被对凋落物养分循环的短期效应受其所处环境条件和作用时间的影响.
Through the removal experiment of undergrowth vegetation in three experimental sites of Huitong fir plantation in Hunan Province, the effects of removing undergrowth vegetation on litterfall decomposition were studied.The results showed that the litterfall of litter layer, semi-decomposed layer and decomposed layer of Chinese fir plantation The existing stocks were (123.7 ± 46.3), (204.2 ± 79.1) and (187.1 ± 94.8) g · m-2 respectively and the corresponding C concentrations were (447.51 ± 16.75), (418.89 ± 35.75) and (376.11 ± 47.33) g · kg-1, (4.87 ± 1.24), (6.4 ± 2.38) and (4.66 ± 2.64) g · kg-1 for P and 0.14 ± 0.01, 0.16 ± 0.03 and 0.16 ± 0.02) g · kg-1. In test sites DL87 and MS90, the removal of undergrowth vegetation had a significant effect on the existing and nutrient reserves of litterfalls, and the results at different sites were inconsistent. The results of DL87’s C, N, P reserves decreased more than 55%, while MS90 increased about 1 time, but had no effect on the existing and nutrient reserves of undecomposed and decomposed layers.The removal of undergrowth vegetation had no significant effect on litter decomposition early stage, After which there was a significant inhibitory effect and the rate of removal of component decomposition decreased by 20.8%. Therefore, the short-term effect of understory vegetation on litter nutrient cycling was affected by its environment Conditions and effects of time.