摘要
气候变暖对湿地生态系统碳循环的影响受到国内外的广泛关注。研究大气增温对植物凋落物分解的影响是掌握气候变暖对湿地生态系统碳循环影响过程及其作用机制的基础。通过开顶式生长室(Open-top Chambers,OTCs)模拟大气增温(2.0±0.5)℃和(3.5±0.5)℃,以滇西北高原典型湿地纳帕海湖滨带的优势植物茭草(Zizania caduciflora)、水葱(Scirpus tabernaemontani)、黑三棱(Sparganium stoloniferum)和杉叶藻(Hippuris vulgaris)为研究对象,研究其凋落物在大气界面,水界面,土-水界面的质量衰减对大气增温的响应。结果表明,(1)大气增温促进了4种植物凋落物在不同分解界面的质量衰减,但其质量衰减率在不同分解界面对增温的响应存在差异。其中,增温对水界面植物凋落物质量衰减的促进作用最大,并随着增温的幅度的增加而增加。其次是土-水界面,增温对大气界面植物凋落物质量衰减的促进作用最小。(2)植物凋落物初始C/N值与其凋落物质量衰减率呈负相关,大气增温对低初始C/N值物种凋落物质量衰减的促进更为显著。(3)相对于大气增温,植物凋落物初始C/N值对其凋落物质量衰减的影响高于大气增温对其质量衰减的影响。研究表明,气候变暖将促进湿地植物凋落物的分解,进而对湿地生态系统物质循环及其生态功能产生影响,其影响程度与湿地植物物种有关,其作用机制有待于进一步深入研究。
The impacts of climate change on the carbon cycle of wetland ecosystems have received considerable attention worldwide. However, the effects of global warming on the decomposition of litter from wetland plants, which is essential for anticipating the effects of climate change on the carbon source/sink function of wetlands, remains poorly understood. In the present study, experimentally examined the influence of atmospheric warming on plant biomass reduction at atmosphere, water, and soil-water interfaces, using open-top chambers that generated different warming conditions （（2.0±0.5）℃ and （3.5±0.5）℃） and four dominant lakeside plants （Zizania caduciflora, Scirpus tabernaemontani, Sparganium stoloniferum, and Hippuris vulgaris） from the Napahai wetland, which is located on the Northwestern Yunnan plateau. The results revealed that （1） experimental warming promoted the mass decay of all four plant species at all interfaces, and the decay rate at the water interface was highest, followed by that at the soil-water interfaces and atmosphere, respectively. （2） The decomposition rates were correlated with the initial C/N ratio of plant litters, regardless of the experimental warming conditions, and the decay of biomass from plants with lower C/N ratios was more sensitive to warming than those with higher ratios. （3） Overall, litter decomposition was affected more by the initial C/N ratio than by the warming treatments. However, the present study still suggests that global warming could promote the decomposition of plant matter in wetland ecosystems in Northwestern Yunnan, with considerable consequences for the carbon cycle and ecological functioning of wetland ecosystems. Accordingly, studies should continue to examine the mechanisms underlying the effects of atmospheric warming on litter decomposition.
作者
张晓宁
刘振亚
李丽萍
王行
张贇
孙梅
肖德荣
ZHANG Xiaoning;LIU Zhenya;LI Liping;WANG Hang;ZHANG Yun;SUN Mei;XIAO Derong(National Plateau Wetlands Research Center, Southwest Forestry University, Kunming 650224, Chin)
出处
《生态学报》
CAS
CSCD
北大核心
2017年第23期7811-7820,共10页
Acta Ecologica Sinica
基金
国家自然科学基金(31370497,31500409)
云南省高原湿地创新团队(2012HC007)
关键词
大气增温
湖滨带植物
凋落物分解
滇西北高原
air warming
dominant lakeside plants
litter decomposition
Northwestern Yunnan Plateau
