吉兰泰盐湖周边荒漠植物养分、叶片功能性状及适应策略研究

Nutrients and Leaf Functional Traits and Adaptive Strategies of Desert Plants around Jilantai Salt Lake

为分析叶片功能性状与养分质量分数的相关关系,探究荒漠植物通过叶片功能性状、养分特征表现出的对环境胁迫的适应策略,以阿拉善盟吉兰泰盐湖区固定沙地生长的荒漠植物为研究对象,对植物叶片的水分与功能性状指标、养分元素质量分数进行测定,运用单因素方差分析、相关性分析等方法对叶片功能性状、养分质量分数以及二者的关系进行分析。结果表明,(1)荒漠植物通过较高的干物质质量分数(LDMC,0.125—0.329 g·g^(−1))、较低的比叶面积(SLA,1.071—23.291 m^(2)·kg^(−1))和叶片含水量(LWC,53.271%—87.102%)来抵御荒漠环境的胁迫,可将这3个指标结合作为荒漠植物筛选的主要性状指标。(2)通过与其他相关研究结果对比,得出荒漠植物叶片通过高水平的N、K、Mg、Na质量分数进行调节,提高植物对水分的利用效率,保证正常生理功能。不同种植物生长受N、P限制的表现不同。(3)荒漠植物通过较高的叶片N、P质量分数来满足植物生长对养分的需要,比叶面积与N质量分数呈正相关,比叶面积高的植物生长速率高,易取得竞争优势;N、P、Na质量分数与叶片干物质质量分数呈极显著负相关,而与叶片含水量呈正相关;Ca、Mg、Na的质量分数与叶片相对含水量和叶片厚度均呈显著正相关关系,Ca、Mg、Na作为植物叶片细胞稳定性及渗透压调节元素在发挥作用。

To analyze the correlation between leaf functional traits and nutrient content,and explore the adaptation strategies of desert plants to environmental stress through leaf functional traits and nutrient characteristics,desert plants growing in fixed sandy land in the Jilantai Salt Lake area of Alashan League were taken as the research objects,and the water and nutrient content and functional traits of plant leaves were measured.Single-factor analysis of variance and correlation analysis were used to analyze their relationship among water content,nutrient content and leaf functional traits.The results showed that,(1)Desert plants could resist the stress of desert environment through higher leaf dry matter content(LDMC),lower specific leaf area(SLA)and lower leaf water content(LWC),with the range of 0.125–0.329 g·g^(−1),1.071–23.291 m^(2)·kg^(−1)and 53.271%–87.102%respectively.The three indexes can be used as the main indexes of desert plant selection.(2)Desert plant leaves can be regulated by high levels of N,K,Mg and Na concentrations to improve the water use efficiency of plants and ensure normal physiological function.The results showed that the growth of different plants was limited by N and P.And(3)desert plants met the nutrient needs of plant growth through higher leaf N and P concentrations;the specific leaf area was positively correlated with N concentration;the plant with higher specific leaf area had higher growth rate and was easy to obtain a competitive advantage;the concentration of N,P and Na was significantly and negatively correlated with leaf dry matter content,but positively correlated with leaf water content.The contents of Ca,Mg,and Na have significantly and positively correlated with leaf relative water content and leaf thickness,and Ca,Mg and Na played an important role in leaf cell stability and osmotic pressure regulation.