遮光对亚热带山地大泥炭藓(Sphagnum palustre L.)生长及维管植物控制效果的影响

控制亚热带山地泥炭藓湿地中维管植物的生长可以帮助泥炭藓湿地快速恢复.以亚热带山地大泥炭藓(Sphagnum palustre L.)为研究对象,采用人工覆盖遮光网控制遮光率,探究遮光对大泥炭藓生长及维管植物控制效果的影响.结果显示:(1)大泥炭藓的生长状态方面,在无遮光下及遮光处理下,随着遮光率的增加,大泥炭藓的头状枝数量不断降低10月从38.9 (±11.8)降低到24.5 (±4.4)],但覆盖面积和生物量先增加后降低10月覆盖面积从62.0 (±32.3) cm²到128.6 (±25.7) cm²再到99.0 (±19.7) cm²;生物量从1.8 (±0.7) g到2.8 (±0.8) g再到2.0 (±0.5) g];(2)随着遮光率的增加,维管植物的总盖度与生物量不断降低10月总盖度从96.2%±1.6%降低到10.0%±1.4%;生物量从419.9(±71.3) g降低到57.4 (±17.1) g];(3)维管植物总盖度与大泥炭藓覆盖面积以及生物量均显著相关,当维管植物总盖度约为50%左右,大泥炭藓覆盖面积和生物量最大.因此,遮光网与维管植物共同影响大泥炭藓的生长,中度遮光(遮光率64%、76%)是帮助泥炭藓湿地快速恢复的最佳条件;综合考虑大泥炭藓的生长以及经济成本,在野外进行大泥炭藓湿地的恢复工作时,只需要覆盖1层遮光网(遮光率64%)即可达到最好效果.(图7表4参38)

Effects of shading on both Sphagnum palustre L. growth and its inhibition of vascular plants in subtropical mountains

In order to accelerate the restoration of Sphagnum wetlands in subtropical mountains, the growth of vascular plants in these wetlands should be controlled. The aim of this study was to assess the effects of shading on both Sphagnum growth and its inhibition of vascular plants in subtropical mountains. Sphagnum palustre L. was used as the experimental organism, and different levels of controlled shading were achieved through artificial shading using different layers of shade net. The growth indicators of both S. palustre and vascular plants were measured monthly, and the effects of shading on each of them were analyzed by one-way ANOVA. In addition, relationships between both the cover and biomass of S. palustre and that of vascular plants were tested by regression analysis. Results showed that the growth status of S. palustre was better in treatments using shade net than that in the treatment without shade net;with increasing shading percentage, the number of capitula of S. palustre decreased continuously(from 38.9(± 11.8) to 24.5(± 4.4) in the last month), while the coverage and biomass showed increased trends at first and then decreased(coverage: first increased from 62.0(± 32.3) to 128.6(± 25.7), then decreased to 99.0(± 19.7) cm²;biomass: first increased from 1.8(± 0.7) to 2.8(± 0.8) g, then decreased to 2.0(± 0.5) g, in the last month). With increasing shading percentage, both the total coverage and biomass of vascular plants decreased(coverage: from 96.2% ± 1.6% to 10.0% ± 1.4%;biomass: from 419.9 ± 71.3 to 57.4 ± 17.1 g in the last month). The relationship between both the coverage and biomass of S. palustre and that of vascular plants was significantly correlated, with the largest coverage and largest biomass of S. palustre occurring when the vascular plant coverage was approximately 50%. We concluded that both the shade net and the vascular plants affect S. palustre growth, and moderate shading levels(64% and 76%) are the optimum condition for rapid restoration of Sphagnum wetlands in subtropical mountains. However, considering both S. palustre growth and economic cost, shading by only one layer of shade net(64% shading) could achieve this optimum condition.