敦煌阳关湿地芦苇叶性状对土壤水分的响应

为了了解干旱区湿地不同水分梯度下芦苇叶性状的构建模式及对不同水分环境的适应策略差异性,以敦煌阳关渥洼池湿地植物芦苇(Phragmites australis)为研究对象,分析不同水分梯度下芦苇叶性状对土壤水分的响应。结果表明:(1)低水分梯度下的叶厚度(LT)和叶片磷含量(LPC)显著高于中、高水分梯度(P0.05),高水分梯度下的叶碳含量(LCC)也显著高于中、低水分梯度(P0.05)。(2)芦苇叶性状之间的关系也因水分的变化而有所不同。就整体而言,叶片碳含量与叶干物质含量(LDMC)极显著正相关(P0.01);叶厚度与叶片磷含量极显著正相关(P0.01),比叶面积(SLA)与叶氮含量(LNC)极显著正相关(P0.01)、与叶碳氮比(C/N)极显著负相关(P0.01)。(3)在水分作为限制因素的条件下,叶片碳含量与比叶面积对水分的响应最为突出。土壤含水量与叶厚度、叶碳含量和叶片磷含量均显著负相关(P0.05)。芦苇在低水分环境下采取高收入低投入的积极型生存策略,高水分下则采取低获取高消耗的保守型生存策略,说明了芦苇在适应异质生境的自我调节机制。

Response of Phragmites australis leaf traits to soil moisture in Yangguan wetland, Dunhuang

In order to understand the construction pattern of Phragmites australis under different water gradients in arid wetlands and to show significant differences in its adaptability to different water environment, the response of this reed''s leaf traits to different soil moisture levels was studied in Dunhuang Yangguan Wowachi wetland. The results showed that:(1) The leaf thickness (LT) and leaf phosphorus content (LPC) in reeds growing in soils with low moisture levels was significantly higher than those growing in soils with medium and high moisture content, and the leaf carbon content (LCC) in high soil moisture areas was significantly higher than those growing in soils with medium and low water content. (2) Also, the relationship between the leaf characteristics of this reed differed with the soil moisture content. As a whole, the LCC was significantly negatively correlated with the leaf dry matter content (LDMC) (P < 0.01), and the LT was significantly positively correlated with the LPC (P < 0.01). The specific leaf area (SLA) was significantly positively correlated with leaf nitrogen content (LNC) (P < 0.01), and significantly negatively correlated with the leaf carbon nitrogen ratio (C/N) (P < 0.01). (3) When water was a limiting factor, for SLA, the response of LCC to soil moisture was the most prominent. Soil water content was significantly negatively correlated with LT, LCC, and LPC (P < 0.05). Phragmites australis adopts a high-income and low-input active survival strategy in a low-moisture environment, and adopts a low-capacity, high-consumption, conservative survival strategy under high water conditions, indicating the self-regulation mechanism of this reed in adapting to heterogeneous habitats.