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滇中地区主要森林凋落物有效截留量及其影响因素
Effective Retention of Main Forest Litter and Its Influencing Factors in Central Yunnan
【摘要】 [目的]研究滇中地区主要森林类型凋落物有效截留量差异及其影响因素,为该地未来植被恢复和森林管理提供科学支撑。[方法]利用样方调查法、烘干法和浸泡法分析了昆明市双河—磨南德水源林自然保护区内的地带性次生常绿阔叶林(SF)、针阔混交林(TF)、旱冬瓜林(ACF)、华山松林(PA)、成熟云南松林(OPY)、幼龄云南松林(YPY)、银荆林(AD)7种主要森林类型凋落物未分解层(OL)和半分解层(OF)的有效截留量及其影响因素。[结果](1) 7种森林类型凋落物厚度为2.06~7.57 cm,其中OL层1.10~4.30 cm, OF层0.83~3.93 cm,凋落物层厚度排序为TF>ACF>PA>OPY>SF>AD>YPY,凋落物蓄积量为4.75~17.45 t/hm~2,其中OL层占比为32.02%~62.48%,OF层占比为37.52%~67.98%,凋落物层蓄积量排序为TF>PA>SF>OPY>ACF>AD>YPY。(2)凋落物最大持水率为115.3%~170.7%,初始吸水速率为3.65~5.62 g/(g·h),凋落物持水率和浸水时间的关系可用对数函数y=aln(x)+b表示,吸水速率与浸水时间可用幂函数y=kt~n表示。(3)凋落物最大持水量为7.05~32.19 t/hm~2,排序为PA>TF>SF>OPY>ACF>AD>YPY,有效截留量为5.45~25.34 t/hm~2,以TF最高(25.34t/hm~2),PA(24.99 t/hm~2)和SF(24.62 t/hm~2)次之,YPY最低(5.45t/hm~2),影响有效截留量的场地特征主要为蓄积量、自然含水率、分解强度以及厚度,影响有效截留量的水动力过程主要是最大失水量、前6.0 h平均吸水速率和前2.0 h平均吸水速率。[结论]滇中地区未来植树造林应以针阔混交林为主,注重对地带性次生常绿阔叶林的保育,采取辅助自然更新的措施促进人工纯林向混交林演化,同时减少踩踏、收集凋落物等人类活动的干扰,从而增加森林生态系统凋落物的水源涵养能力。
【Abstract】 [Objective] The aims of this study are to investigate variations in the effective retention of litter within main forests and the influence factors, and to provide scientific support for future vegetation restoration and forest management. [Methods] we employed a combination of field surveys and indoor water immersion experiments within the Shuanghe-Monande Nature Reserve located in Kunming City, the central of Yunnan Province. We studied site characteristics and hydrodynamic processes of seven representative types of forest: Secondary Forest(SF), Theropencedrymion forest(TF), Alnus cremastogyne forest(ACF), Pinus armandii forest(PA), Old Pinus yunnanensis forest(OPY), Young Pinus yunnanensis forest(YPY), Acacia dealbata forest(AD). [Results](1) The litter thickness of seven types of forest ranged from 2.06 to 7.57 cm, with OL layer 1.10~4.30 cm and OF layer 0.83~3.93 cm, and ranked as TF>ACF>PA>OPY>SF>AD>YPY. The litter accumulation volume ranged from 4.75 to 17.45 t/hm~2, with OL layer accounting for 32.02%~62.48% and OF layer 37.52%~67.98%, and ranked as TF>PA>SF>OPY>ACF>AD>YPY.(2) The maximum water holding rate of litter was 115.3%~170.7%, and the initial water absorption rate was 3.65~5.62 g/(g·h), and their correlation with water immersion were described by logarithmic function y=aln(x)+b and power function y=kt~n.(3) The maximum water holding capacity of litter ranged from 7.05 to 32.19 t/hm~2, ranked as PA>TF>SF>OPY>ACF>AD>YPY. The effective holding capacity ranged from 5.45 to 25.34 t/hm~2, and TF was the highest(25.34 t/hm~2), followed by PA(24.99 t/hm~2) and SF(24.62 t/hm~2), while YPY had the lowest capacity(5.45 t/hm~2). The effective storage capacity of litter ranged from 5.45 to 25.34 t/hm~2, with the same ranking as water holding capacity. The site characteristics that influenced the effective storage volume included litter storage volume, natural water content, decomposition intensity, and thickness. The hydrodynamic processes affecting the effective storage volume included maximum water loss, average absorption rate in initial 6.0 hours, and average absorption rate in initial 2.0 hours. [Conclusion] For future afforestation efforts in the central Yunnan region, we recommend to prioritize the establishment of mixed needle-broad forests and conserve the zonal evergreen secondary forests. To facilitate the evolution of artificial monoculture forests towards mixed forests, it is advisable to implement measures for natural regeneration. Furthermore, it is crucial to minimize human activities, such as trampling and excessive litter collection, which can disrupt forest ecosystem. By doing so, the water retention capacity of forest system can be enhanced through effective conservation of litter.
【Key words】 litter; main types of forest; water holding characteristics; effective retention; central Yunnan region;
- 【文献出处】 水土保持研究 ,Research of Soil and Water Conservation , 编辑部邮箱 ,2024年03期
- 【分类号】S714
- 【下载频次】72