野猪翻拱对凋落物氮去向的影响研究

Litter decomposition process, along with the release of nitrogen (N), is an important part of the forest ecosystem nitrogen cycle, which affects the soil nitrogen availability and determines the ecosystem primary productivity as well as carbon sequestration. Because of increasing in wild boar, the uprooting area and depth to litter-soil interface layer are increasing, which are seriously affecting cycling of N in the soil. This project is to choose a broad-leaved Korean pine forest in Changbai mountain China as the research site, establish fences to exclude disturbance of the boar to the litter-soil interface layer, combining with the regular survey fence outside of woodland, looking for the treatment plots disturbed by wild boar. We are planning to use Korean pine, Mongolian oak and Tilia leaf litter that have been labeled by stable isotope 15N, bury the litter in the wild boar uprooted plots and place the litter on the surface of the plots, and measure the fate of N derived from the litter: N2O, NO3-, microbial biomass N, fine roots N and soil organic-inorganic association. The results would reveal mechanism that the boar disturbing effects on litter N losses (N2O gas and NO3- leaching) and retention (microbes, plants and soil organic matter), propose the model about the N cycling of broad-leaved Korean pine forest under wild boar disturbance, and afford parameterization for forest N cycle models, as well as support scientific evidence for the temperate forests N cycle and ecosystem management.

凋落物分解过程氮素的释放是森林生态系统氮循环的重要环节，影响土壤氮有效性，进而决定着生态系统初级生产力和固碳功能。土壤动物通过对凋落物的破碎影响土壤碳氮循环已引起广泛关注，但有关大型野生动物对森林地表层频繁扰动的影响却鲜有报道。本项目以我国长白山阔叶红松林为研究对象，采用铁蒺藜围栏方式建立免野猪翻拱样地，并结合定期勘察围栏外林地，获得野猪翻拱干扰样地，应用15N稳定同位素标记的红松、蒙古栎和紫椴叶凋落物，研究野猪翻拱埋藏和凋落于翻拱迹地表面两种情形下，凋落物分解过程中氮素的五个重要去向：N2O，NO3-，微生物固持氮，细根吸收氮和有机氮-矿质复合体；揭示野猪翻拱对凋落物氮损失和存留的影响机制，提出野猪翻拱干扰下长白山阔叶红松林氮循环模式，为森林氮循环模型提供参数，也为维系大型野生动物种群数量与森林资源保护之间的平衡提供科学依据。

凋落物分解过程氮素的释放是森林生态系统氮循环的重要环节，影响土壤氮有效性，进而决定着生态系统初级生产力和固碳功能。土壤动物通过对凋落物的破碎影响土壤碳氮循环已引起广泛关注，但有关大型野生动物对森林地表层频繁扰动的影响却鲜有报道。本项目以我国长白山温带典型森林生态系统-原始阔叶红松林和次生杨桦林研究对象，采用铁蒺藜围栏方式建立免野猪翻拱样地，并结合远程红外监控和定期勘察围栏外林地，获得野猪翻拱干扰样地，应用15N稳定同位素标记的紫椴叶凋落物，研究排除野猪翻拱干扰和翻拱干扰造成的埋藏以及凋落于翻拱迹地表面情形下，凋落物分解过程中氮素的五个重要去向：N2O，NO3-，微生物固持氮，细根吸收氮和有机氮-矿质复合体，同时分析了土壤生物群落对干扰的响应；揭示野猪翻拱对凋落物氮损失和存留的影响机制，提出长白山阔叶红松林和次生白桦林氮循环模式，为森林氮循环模型提供参数，也为维系大型野生动物种群数量与森林资源保护之间的平衡提供科学依据。在项目执行期内共发表带项目标注的学术论文7篇（其中SCI索引收录5篇），专利2项，培养研究生7名。