Study Of Characteristics And Influence Factors On Microelements Of Different Plantations In Karst Area

Five different types of plantations (Prunus salicina、Eucommia ulmoides、Cupressusduclouxiana、Alnus cremastogyne、Robinia pseudoacacia) were studied from Puding countyGuizhou province in Karst mountainous site. The contents of soil and tree species microelements(Fe Mn Cu Zn Mo and Co) were determined by the equipment ICP–MS, and analyzed theirrelationship between each others. Their relationships with the contents of soil organic matter andpH value were analyzed by the correlation analysis method. In the meantime we had comparedthe content of microelements in the leaves of five tree species. The results indicated that:(1) The highest and lowest contents of soil microelements was Fe and Mo. The contents ofsoil available microelements showed surface accumulation effect. There were some differencesbetween the correlation of available microelements and total amount microelements.(2) There existed the regularities of Fe＞Mn＞Cu＞Zn＞Co＞Mo for single microelementavailability index and Cupressus duclouxiana stand> Robinia pseudoacacia stand> Eucommiaulmoides stand> Prunus salicina stand> Alnus cremastogyne stand for comprehensivemicroelement availability index in different types of plantations. Five different types ofplantations were lack of available Mo Co, whose contents were all lower than the criticalcontents, which the plants grow need. Prunus salicina stand was favorable for the accumulationof six microelements, Alnus cremastogyne stand was not for that. The available rates of sixmicroelements in the soil were in the order of Cu＞Zn＞Mo＞Mn＞Fe＞Co.(3) The contents of soil organic matter was in the range of50.93-117.88g·kg-1, and showedsurface accumulation effect. Six microelements contents showed a upward trend with increasingsoil organic matter contents, and caused significant positive effect on available microelements.Soil pH value was in the range of7.58-8.56. Six microelements contents showed a downwardtrend with increasing pH value, and caused significant negative correlation on total Mn Cu MoCo and available Fe Mn.(4) The contents of six microelements in plants were in the order of Fe＞Mn＞Zn＞Cu＞Mo＞Co, and was more than available microelements in soil. There existed the regularities of Zn＞Mo＞Cu＞Mn＞Fe＞Co for bio-absorption coefficients of tree species in different types ofplantations. Microelements accumulated ability of Cupressus duclouxiana was stronger than theother four types of tree species.