荒漠地区8种草本植物营养元素含量的比较分析

Comparative Analysis of Nutrient Elements of Eight Herbaceous Plants in Desert Area

为深入了解荒漠植物营养元素计量特征,认识元素间的交互作用,揭示不同生长期、不同沙丘部位植物元素含量差异。以古尔班通古特沙漠8种优势草本植物(4种1年生植物,4种短命植物)为研究对象,采集不同生长期(旺盛期、枯萎期)、不同沙丘部位(坡上、腹地)的植株,测定全株植物的10种营养元素(C、N、P、K、Na、Mg、Al、Mn、Cu、Zn)。结果表明:(1)8种植物元素含量存在显著差异,体现了植物因遗传特性不同而对元素选择吸收的特点,含量为:C(230.19~401.82 mg·g^(-1))、N(11.31~18.85 mg·g^(-1))、P(0.95~2.08 mg·g^(-1))、K(16.12~29.79 mg·g^(-1))、Na(0.88~3.31 mg·g^(-1))、Mg(3.38~5.31 mg·g^(-1))、Al(0.33~1.99 mg·g^(-1))、Mn(51.35~105.32 mg·kg^(-1))、Cu(4.14~6.38 mg·kg^(-1))、Zn(11.64~21.43 mg·kg^(-1))。不同种的元素含量分布格局基本相似,大小排序为:C>N>K>Mg>Na>P>Al>Mn>Zn>Cu,典型特征为富K,贫Cu、Zn,属于N制约性植物,表明环境对各类植物元素含量的一致影响。(2)元素含量受物种、生长期和沙丘部位的影响显著。4种黎科植物(Chenopodiaceae)Na含量显著比4种短命植物高。与生长旺盛期相比,8种植物在枯萎期的C、N、P、Mg、Mn、Cu、Zn含量普遍降低,而Na、K含量有不同幅度的升高,并且碱蓬、沙蓬的K含量显著升高。受土壤水分和养分丰富程度的影响,沙丘腹地植物元素含量普遍比坡上同种植物高。(3)相关性分析表明:C与P,N与Na、Mg、Cu、Zn,K与P、Al,Na与Mg,Mn与Na、Mg、Cu,Zn与Cu之间具有极显著正相关关系(P≤0.001),P与Cu,C与Cu、Zn,K与Mn、Cu、Zn之间具有极显著负相关关系(P≤0.001)。综上所述,荒漠植物元素含量的这些特征体现了其对干旱半干旱地区气候和土壤等生存环境的适应性。

In order to better understand the quantitative characteristics of nutrient elements in desert plants and the interaction among elements,the differences of plant element contents in different growing stages and dune areas were revealed.Eight dominant herbs(four kinds of annual plants,four kinds of ephemeral plant)in Gurbantunggut desert were used to collect plants from different growth period(vigorous period,wither period)and different sand dune areas(slopes,hinterland),and 10 kinds of nutrient elements(C,N,P,K,Na,Mg,Al,Mn,Cu and Zn)in whole plant were measured respectively.The results showed that:(1)There were significant differences in element contents of 8 species,which reflected the characteristics of selective absorption of elements due to different genetic characteristics.The contents were as follows:C(230.19-401.82 mg·g^(-1))and N(11.31-18.85 mg·g^(-1)),P(0.95-2.08 mg·g^(-1)),K(16.12-29.79 mg·g^(-1)),Na(0.88-3.31 mg·g^(-1)),Mg(3.38-5.31 mg·g^(-1)),Al(0.33-1.99 mg·g^(-1)),Mn(51.35-105.32 mg·kg^(-1)),Cu(4.14-6.38 mg·kg^(-1)),Zn(11.64-21.43 mg·kg^(-1)).The distribution pattern of element contents of different species was similar,and the order of element contents was:C>N>K>Mg>Na>P>Al>Mn>Zn>Cu,typical characteristics were rich in K but poor in Cu and Zn,belonging to N restrictive plants,demonstrated consistent impact of environmental elements for all kinds of plants.(2)Element contents were significantly affected by species,growing period and dune location.The Na contents of four species of Chenopodiaceae were significantly higher than those of four ephemeral plants.Compared with the flourishing stage,the contents of C,N,P,Mg,Mn,Cu and Zn of the eight plants were generally decreased in the withered stage,while the contents of Na,K increased by different degrees,and the K content of Suaeda glauca and Agriophyllum sqarrosum significantly increased.The content of plant elements in the hinterland of sand dune was generally higher than that of the same species on the slope due to the influence of soil moisture and nutrient.(3)Correlation analysis showed that:C was positively correlated with P,N with Na,Mg,Cu,Zn,K with P,Al,Na with Mg,Mn with Na,Mg,Cu,Zn with Cu(P≤0.001)respectively,but K was negatively correlated with Mn,Cu and Zn(P≤0.001).In conclusion,the characteristics of element contents of desert plants reflected their adaptability to climate and soil in arid and semi-arid areas.