石灰岩特有植物圆叶乌桕土壤与叶片化学元素含量特征  

Characteristics of Chemical-element Contents in Leaves and Growing Soils of Triadica rotundifolia,A Limestone Endemic Species

作　　者：刘锡辉[1] 秦新生[1] 梁同军[2] 林森[1] 

机构地区：[1]华南农业大学林学院,广东广州510642 [2]江西省中国科学院庐山植物园,江西九江332900

出　　处：《西南农业学报》2013年第3期1195-1200,共6页Southwest China Journal of Agricultural Sciences

基　　金：广东省自然科学基金(8451064201001149);国家高等学校本科特色专业建设点-林学(教高函[201015]号);广东省林业科技创新专项资金(2009KJCX014);广东省大学生创新实验计划(1056411009)

摘　　要：对石灰岩特有植物圆叶乌桕与同属的乌桕、山乌桕叶片及其生长地土壤化学元素进行测定,比较三者化学成分特征,分析了圆叶乌桕在广东石灰岩地区的环境适应特点。结果表明:圆叶乌桕生长地的有机质、全N及全P含量均高于乌桕、山乌桕生长地,N素和P素有效率较低,速效N仅占全N含量的6.88%,速效P仅占全P的4.77%,全K含量偏低,但圆叶乌桕生长地速效K含量(151.8 mg.kg-1)达到土壤速效K含量对应的适量K(125～155 mg.kg-1)水平等级,属适量K型土壤,交换性Ca及交换性Mg含量均高于乌桕、山乌桕生长地,微量元素含量排序为Mn>Pb>Cr>Zn>Ni>Fe>Cd>Cu,全Pb、全Zn及全Cu含量均未超过国家规定的3级标准。圆叶乌桕叶片Ca含量(25.24 g.kg–1)、Cd含量(0.45 mg.kg-1)高于乌桕、山乌桕。土壤中植物营养元素含量较低的元素如K、Fe和Cu在圆叶乌桕叶片中的生物吸收系数较高,而土壤中含量较高的元素如N、Ca、P、Mg、Mn和Zn在其叶片中生物吸收系数较低。在高温干旱的胁迫下,圆叶乌桕叶片会吸收一定量的Ca,提高抗逆性。圆叶乌桕的化学元素特征反映了它对石灰岩生境的适应性较强。Chemical element contents within both soil and leaves of Triadica rotundifolia,T.sebifera and T.cochinchinensis were determined,and the environmental adaptive mechanisms of three Triadica species based on their chemical composition characteristics were also analyzed.The results showed that the contents of organic matter,total N and P were higher in the soil of T.rotundifolia than that in T.sebifera and T.cochinchinensis soil.The contents of available N and P were very low with the value of 6.88 % and 4.77 %,respectively,total K content in calcareous soil was also lower,while available K content（151.8 mg·kg-1） in T.rotundifolia soil reached K-minimum soils（125-155 mg· kg-1）,so the limestone soil was classified as a K minimum soil.The contents of exchangeable Ca and Mg in T.rotundifolia soil were higher than that in T.sebifera and T.cochinchinensis soil.The microelement contents in limestone soil was in order of MnPbCrZnNiFeCdCu.The contents of total Pb,Zn and Cu were not higher to the third State standards so that vegetation restoration was feasible in calcareous soil.the content of Ca and Cd in T.rotundifolia leaves were higher with the value of 25.24 and 0.45 mg·kg-1 than that in T.sebifera and T.cochinchinensis leaves.Those nutrient elements,which were lower in T.rotundifolia soil,had higher biological absorption coefficients in T.rotundifolia leaves,such as K,Fe and Cu,while those,which were higher in T.rotundifolia soil,had lower biological absorption coefficients in T.rotundifolia leaves,such as N,Ca,P,Mg,Mn and Zn.Under conditions of high temperature and drought,T.rotundifolia leaves absorbed a certain amount of Ca to enhance stress resistance.All of these indicated that T.rotundifolia could be well adapted to limestone habitats condition.

关 键 词：石灰岩 圆叶乌桕 乌桕 山乌桕 化学元素 土壤 叶片 

分 类 号：Q946.91[生物学—植物学]