中文摘要：

我国东北泥炭地大多存在直叶金发藓优势度增加的现象，其内在机制尚不清楚。以大泥炭藓、中位泥炭藓和直叶金发藓为材料，在哈泥泥炭地选取潜水位差异明显的两个生境，人工构建苔藓群落，研究潜水位和邻体对3种苔藓形态及生化指标的影响。结果表明：潜水位降低抑制两种泥炭藓的高增长和中位泥炭藓的可溶性糖含量，增加两者分枝生产和N含量，而直叶金发藓除生物量受到抑制，分枝生产受到促进外，其他指标均无响应；在混合群中，两种泥炭藓相互促进彼此的高增长和生物量生产，直叶金发藓抑制大泥炭藓的分枝生产和中位泥炭藓的C含量，但两种邻体对直叶金发藓的各项指标影响甚微。研究表明，直叶金发藓尽管未对泥炭藓产生直接的竞争效应，但是凭借其良好的耐旱能力，仍能在气候变暖以及人为干扰导致的潜水位下降的背景下，获得竞争优势，实现种群的扩展。

英文摘要：

The dominance of non-Sphagnum mosses such as Polytrichum strictum has increased in some peatlands of NE China while the mechanism is not clear. We performed a one-year experiment in Hani Peatland with three mosses, Sphagnum palustre, S. magellanicum and P. strictum in two typical habitats with different water table depth. We tried to explore the effects of water table and neighbor on morphological traits including height increment, biomass production and side-shoot production and biochemical traits including carbon and nitrogen content and soluble sugar content. Two Sphagnum mosses both responded to water table drawdown with the increasing of side-shoot production and nitrogen content but decreasing height increment. S. magellanicum also responded with the decreasing of soluble sugar content. Except for the inhibitive effect on biomass production and the facilitation effect on side-shoot production, no other traits in P. stricture were affected by water table drawdown. In mixed culture, two Sphagnum species mutually promoted their height increment and biomass production. Side-shoot production in S. palustre and carbon content in S. magellanicum were negatively affected by neighbor P. strictum, while neither neighbor had any effects on P. strictum. Although P. strictum did not have a direct competition effect on two Sphagnum mosses, and by virtue of its good drought tolerance, it could still get the competitive advantage and realize population expansion in peatlands in the background of climate warming and water table drawdown resulted from disturbance by human beings.