海岸带信息集成与战略规划研究中心知识库

(1) 北京林业大学自然保护区学院

Clonal integration is one of the most important traits of clonal plants. It not only can improve the ability of ramets to tolerate environmental stress,but also may influence physicochemical properties of the soil around the ramets. To test the effect of clonal integration on soil properties, we conducted a field experiment in a wetland dominated by Phragmites australis in the Yellow River Delta in China, with clonal integration and crude oil contamination as the two main factors. We added 0,5, or 10 mm thick crude oil per year to circular plots (60 cm in diameter) of the P. australis community to simulate none,moderate,or heavy oil contamination,and kept the rhizome connections between the ramets of P. australis inside and outside the plots severed or not, to prevent or allow clonal integration. The experiment started in 2014. In October 2016,we collected soil samples in the plots and measured soil aggregate composition, pH, electric conductivity, total carbon, total nitrogen, total phosphorus, and organic carbon. Crude oil contamination significantly increased the proportion of large macroaggregates (diameter >2.0 mm),pH, total nitrogen, and organic carbon in the soil, but decreased the proportion of soil microaggregates (diameter: 0.053-0.25 mm) and soil electric conductivity. Clonal integration significantly decreased soil pH, but increased soil electric conductivity, and nitrogen to phosphorus ratio. There was a significant interaction effect between clonal integration and oil contamination only on soil electric conductivity. Therefore, both crude oil contamination and clonal integration can influence physicochemical properties of the soil in wetlands,and the effect of clonal integration on physicochemical properties of the soil around the ramets may further affect the dominance of clonal plants.

克隆整合是克隆植物重要的性状之一。它不仅能够提高分株对环境胁迫的耐受能力,而且可能影响分株周围的土壤属性。为检验克隆整合对土壤属性的影响,在黄河三角洲芦苇湿地开展克隆整合和石油污染的两因子的野外实验。每年将0、5或10 mm厚的原油添加到直径为60 cm的圆形芦苇群落样方内来模拟无污染、轻度或重度石油污染,并通过保留或切断样方内外芦苇根状茎的连接来实现克隆整合的有或无。实验开始于2014年,并于2016年10月采集样方内土壤样品,测定土壤团聚体组成、pH值、电导率、总碳、总氮、总磷和有机碳含量。石油污染显著增加了土壤粗大团聚体(粒径:>2 mm)、pH值、总氮和有机碳含量,降低了土壤微团聚体(粒径:0.0530.25 mm)占比以及电导率。克隆整合显著降低了土壤pH值,提高了土壤电导率和氮磷比。克隆整合和石油污染的交互作用仅对电导率有显著效应。因此,石油污染和克隆整合都可以影响湿地土壤的理化性质,而克隆整合对分株周围土壤理化性质的影响可能进一步影响克隆植物的优势度。