滇西北水蓼叶功能性状的关联性及其对气候因子的响应

Correlations of leaf functional traits of Persicaria hydropiper and its responses to climatic factors in Northwest Yunnan

关键词:  高原湿地, 植物功能性状, 响应策略, 海拔, 气候因子

Key words:  plateau wetland, plant functional trait, responsive strategy, altitude, climatic factor

摘要:

研究湿地植物对气候变化的响应是了解湿地生态系统应对气候变化的基础。该文以滇西北剑湖、拉市海、泸沽湖和纳帕海共有的湖滨带挺水植物水蓼(Persicaria hydropiper)为研究对象,测定其功能性状,并收集4个样点的海拔高度和气候因子,通过冗余分析检测水蓼功能性状与气候因子间的关系,探讨这些功能性状的气候响应差异。结果表明:(1)水蓼气孔密度和比叶质量沿海拔高度的升高显著增加,而气孔导度、导管面积、气孔面积、叶碳质量分数及叶氮质量分数沿海拔高度的升高而显著降低(P<0.05)。(2)年平均温度、年平均降水量和年平均空气相对湿度是影响水蓼功能性状的最主要气候因子,水蓼更加倾向于生长在温度、降水和空气湿度均相对较高的低海拔生境。(3)水蓼各功能性状存在相关性,净光合速率与叶脉密度、比叶质量、叶磷质量分数间呈显著正相关,而与筛管面积间呈显著负相关(P<0.05),气孔导度和蒸腾速率均与茎粗、气孔大小及叶碳质量分数间呈显著正相关,蒸腾速率与株高间也呈显著正相关(P<0.05)。该研究揭示了影响水蓼功能性状的主要环境因子,也为气候变化背景下水蓼的功能适应性提供了科学数据。

Abstract:

The study of the response of wetland plants to climate change is the foundation for understanding the response of wetland ecosystem to climate change. This study took Persicaria hydropiper, one type of emergent aquatic plant in the lakeside zone of Jianhu, Lashihai, Luguhu and Napahai in Northwest Yunnan, as the research object. The species' functional traits were measured, the altitude and climatic factors of four sampling sites were collected, and the relationship between functional traits of P. hydropiper and climatic factors was detected through redundancy analysis to explore climate response variations of these functional traits. The results were as follows:(1)The stomatal density and leaf mass per area of P. hydropiper significantly increased with the increase of altitude, however, stomatal conductance, conduit area, stomatal area, leaf carbon mass fraction, and leaf nitrogen mass fraction significantly decreased with increasing altitude(P<0.05).(2)The mean annual temperature, mean annual precipitation, and mean annual air relative humidity were the main climatic factors affecting the functional traits of P. hydropiper. The species preferred to grow in low altitude habitats with relatively high temperature, precipitation, and air humidity.(3)There was a functional correlation between the functional traits of P. hydropiper. Net photosynthetic rate was significantly and positively correlated with leaf vein density, leaf mass per area, and leaf phosphorus mass fraction, while it was significantly and negatively correlated with sieve tube area(P<0.05). Stomatal conductance and transpiration rate were significantly and positively correlated with stem diameter, stomatal size, and leaf carbon mass fraction. Transpiration rate was also significantly and positively correlated with plant height(P<0.05). This study reveals the main environmental factors that affect the functional traits of P. hydropiper, and provides scientific data for its functional adaptability in the context of climate change.