控雪处理下红松和蒙古栎凋落叶分解动态  

Dynamics in foliar litter decomposition for Pinus koraiensis and Quercus mongolica in a snow-depth manipulation experiment

作　　者：武启骞[1] 王传宽[1] WU Qi-Qian and WANG Chuan-Kuan(Center for Ecological Research, Northeast Forestry University, Harbin 150040, Chin)

机构地区：[1]东北林业大学生态研究中心,哈尔滨150040

出　　处：《植物生态学报》2018年第2期153-163,共11页Chinese Journal of Plant Ecology

基　　金：国家"十二五"科技支撑项目(2011BAD37B01);长江学者和创新团队发展计划(IRT_15R09);中央高校基本科研业务费专项(2572014AA11)~~

摘　　要：气候变化导致的冬季雪被格局变化将改变地表水热环境及分解者活性,从而显著影响高寒地区森林凋落物分解过程。2014–2016年采用凋落物分解袋法,研究了帽儿山森林生态站人工林控雪模拟试验下红松(Pinus koraiensis)和蒙古栎(Quercus mongolica)的凋落叶于雪被期和无雪期不同阶段的分解动态。控雪试验包括增雪、除雪和对照3个处理。结果发现:树种、控雪处理、分解阶段以及环境因子(凋落物层平均温度、冻融循环次数、有机层全氮、全磷含量等)均影响着凋落叶分解率。分解试验的两年内,不同控雪处理下红松凋落叶的分解率为52.1%–54.5%,蒙古栎为53.9%–59.1%。两种凋落叶的分解系数均以增雪处理最大,除雪处理最小。此外,控雪处理改变了两种凋落叶雪被期或无雪期对分解总量的贡献率。与对照相比,增雪处理使红松和蒙古栎凋落叶雪被期的分解贡献率分别提高9.1%和10.4%;而除雪处理使两种凋落叶无雪期的分解贡献率分别提高10.4%和12.7%。因此,由气候变化带来的冬季雪被改变不但会显著影响温带森林凋落叶的分解过程,而且会改变雪被期和无雪期的分解量对年分解总量的贡献率。Aims Changes in snowpack induced by climate change may alter water and heat regimes at the ground surface, thus influencing activities of decomposers and litter decomposition in snow-covered regions. However, effects of snow-depth changes on litter decomposition are unclear. Our objective was to characterize the decomposition dynamics of two contrasting tree species—Korean pine （Pinus koraiensis） and Mongolian oak （Quercus mongolica） in a snow-depth manipulation experiment.Methods The snow-depth manipulation experiment that included three treatments （i.e., snow-addition, snow-removal, and control） was conducted in a temperate Korean pine plantation in the Maoershan Forest Ecosystem Research Station, Northeast China. Air-dried foliar litter of the pine or oak （10 g litter per bag） was sealed in a nylon litterbag （15 cm × 20 cm）. A total of 648 litterbags （3 plots × 3 treatments × 2 tree species × 3 replicates × 12 sampling dates） were placed evenly on the forest floor in October 2014. Three replicate litterbags per species were buried in each treatment plot and sampled 12 times （i.e., freezing onset stage, deep freezing stage, thawing stage, early, middle and late snow-free seasons） during the two-year period （2014-2016） to determine the temporal variation of the decomposition rate. Associated factors （i.e., mean temperature at litter layer, freeze-thaw cycle, available nitrogen and phosphorus at the organic layer） were measured simultaneously.Important findings Tree species, snow-depth treatment, decomposition stage, and the measured associated factors all influenced the decomposition rates of the foliar litter. The litter mass loss was 52.1%-54.5% for the pine, and 53.9%-59.1% for the oak during the two-year period. The decomposition coefficients for the litter of the two species were the highest in the snow-addition plot, and the lowest in the snow-removal plot. Moreover, the snow-depth manipulation dramatically changed the relative contribution of the mass loss （R r

关 键 词：控雪 温带森林 凋落物分解 气候变化 雪被期 无雪期 

分 类 号：S714[农业科学—林学]