Absorption,accumulation and distribution of Pb,Cd,Cr,Cu,Mn,Ni,Zn,P and S elements in loblolly pine plantation in the hilly regions of southern Jiangsu province were studied.The results show that the storage of nine el...Absorption,accumulation and distribution of Pb,Cd,Cr,Cu,Mn,Ni,Zn,P and S elements in loblolly pine plantation in the hilly regions of southern Jiangsu province were studied.The results show that the storage of nine elements in the soil of the forest is in order of S>P>Mn>Zn>Cr>Cu>Pb>Ni>Cd,their contents in different organs of trees are quite different,being Pb 0 96～5 81,Cd 0 266～0 720,Cr 8 55～9 49,Cu 4 36～9 44,Mn 18 98～61 07,Ni 1 74～9 03,Zn 13 44～32 69,P 168～987,and S 446～1770(mg·kg -1 ).Their accumulation ratios of elements in plants are in order of Cd >P>S>Cu>Zn>Cr>Pb>Ni> Mn.The accumulation amounts of Pb,Cd,Cr,Cu,Mn,Ni,Zn,P and S in the biomass of the community are 36 30 ,5 47,85 58,74 54,248 1,26 81,236 5,3268,and 8158 (mg·m -2 ),respectively,of which the overground part accounted for 5 37%,10 60%,23 77%,15 99%,16 61%,12 38%,12 34%,24 85%,and 4712%,higher than underground part.The biological cycles of the elements in the community are described as follows:annual uptake is Pb 23 75,Cd 1 97,Cr 24 07,Cu 27 44,Mn 170 17,Ni 19 51,Zn 109 29,P 1721 69,and S 2843 14 (mg·m -2 ).Annual return is Pb 12 70,Cd 0 68,Cr 1 66,Cu 10 49,Mn 70 72,Ni 6 46,Zn 40 60,P 257 61,and S 486 56 (mg·m -2 ).The turnover periods of nine elements are 3,8,52,7,4,4,6,57 and 17 years respectively.展开更多
This paper deals with a study on the effects of Chinese fir, loblolly pine and deciduous oak forests on thenutrient status of soils in northern subtropics of China, adopting the principle of forest ecology in the case...This paper deals with a study on the effects of Chinese fir, loblolly pine and deciduous oak forests on thenutrient status of soils in northern subtropics of China, adopting the principle of forest ecology in the caseof similar climate and soil type. The experimental area was situated in the Xiashu Experimental Centre ofForest, where the soil is yellow-brown soil derived from siliceous slope wash. Sample plots of these 3 standswere established to study the nutrient status in litter, the amount of nutrient uptake by roots, the quantityof nutrient output by percolating water outside the deep layer of soil, and the seasonal dynamics of availablenutrient in surface soil. It was shown that the intensity of nutrient cycling in soil under deciduous oak wasthe highest, and the effect of oak in improving soil fertility was the best. The result of improving soil fertilityby Chinese fir was the most inferior, though the intensity of nutrient cycling under that stand was higherthan that under loblolly pine stand. The influence of loblolly pine on the improvement of soil fertility wasbetter than that of Chinese fir, in spite of its lowest intensity of nutrient cycling.展开更多
文摘Absorption,accumulation and distribution of Pb,Cd,Cr,Cu,Mn,Ni,Zn,P and S elements in loblolly pine plantation in the hilly regions of southern Jiangsu province were studied.The results show that the storage of nine elements in the soil of the forest is in order of S>P>Mn>Zn>Cr>Cu>Pb>Ni>Cd,their contents in different organs of trees are quite different,being Pb 0 96～5 81,Cd 0 266～0 720,Cr 8 55～9 49,Cu 4 36～9 44,Mn 18 98～61 07,Ni 1 74～9 03,Zn 13 44～32 69,P 168～987,and S 446～1770(mg·kg -1 ).Their accumulation ratios of elements in plants are in order of Cd >P>S>Cu>Zn>Cr>Pb>Ni> Mn.The accumulation amounts of Pb,Cd,Cr,Cu,Mn,Ni,Zn,P and S in the biomass of the community are 36 30 ,5 47,85 58,74 54,248 1,26 81,236 5,3268,and 8158 (mg·m -2 ),respectively,of which the overground part accounted for 5 37%,10 60%,23 77%,15 99%,16 61%,12 38%,12 34%,24 85%,and 4712%,higher than underground part.The biological cycles of the elements in the community are described as follows:annual uptake is Pb 23 75,Cd 1 97,Cr 24 07,Cu 27 44,Mn 170 17,Ni 19 51,Zn 109 29,P 1721 69,and S 2843 14 (mg·m -2 ).Annual return is Pb 12 70,Cd 0 68,Cr 1 66,Cu 10 49,Mn 70 72,Ni 6 46,Zn 40 60,P 257 61,and S 486 56 (mg·m -2 ).The turnover periods of nine elements are 3,8,52,7,4,4,6,57 and 17 years respectively.
文摘This paper deals with a study on the effects of Chinese fir, loblolly pine and deciduous oak forests on thenutrient status of soils in northern subtropics of China, adopting the principle of forest ecology in the caseof similar climate and soil type. The experimental area was situated in the Xiashu Experimental Centre ofForest, where the soil is yellow-brown soil derived from siliceous slope wash. Sample plots of these 3 standswere established to study the nutrient status in litter, the amount of nutrient uptake by roots, the quantityof nutrient output by percolating water outside the deep layer of soil, and the seasonal dynamics of availablenutrient in surface soil. It was shown that the intensity of nutrient cycling in soil under deciduous oak wasthe highest, and the effect of oak in improving soil fertility was the best. The result of improving soil fertilityby Chinese fir was the most inferior, though the intensity of nutrient cycling under that stand was higherthan that under loblolly pine stand. The influence of loblolly pine on the improvement of soil fertility wasbetter than that of Chinese fir, in spite of its lowest intensity of nutrient cycling.
