关 键 字(英文)：Sediment element Concentration Liquid phase Correlation
摘 要(英文)：The monsoon evergreen broad-leaved forest (MEBF) in Dinghushan Biosphere Reserve , Guang2
dong Province , China , is considered climax forest vegetation in this climatic zone. Studies of its ecological pro2
cesses , including the hydrology and inorganic solution chemistry , are important for understanding ecosystem
function and to direct ecological restoration efforts in this region. In order to understand the response of nutri2
ent cycles to environmental impacts and characterize the nutrient element cycles in this ecosystem , water sam2
ples of precipitation , throughfall , soil water at 30 and 80 cm depth and runoff in MEBF were collected weekly
and the concentrations of eight inorganic elements measured from February 2001 to March 2002. The elements
Al3 + , Mn2 + , Sr2 + and Pb2 + were measured by ICP (ps-1000AT , USA) , Ca2 + and Mg2 + were analyzed us2
ing Atomic Absorption Spectrometer , and K+ and Na + were determined using Flame Atomic Absorption Spec2
trometer. The results showed that the average concentration of Al3 + in throughfall (0. 393 3 mg·L - 1) was
slightly higher than that in precipitation (0. 329 mg·L - 1) . The average concentrations of Al3 + soil solutions
were much higher than in precipitation and were about 4. 7 times and 3. 8 times higher in soil water collected
at 30 cm depth and runoff , respectively. Al3 + in runoff was derived primarily from soil leaching. Average con2
centrations of Mn2 + , K+ and Mg2 + were lowest in precipitation and Sr2 + and Ca2 + concentrations were lowest
in runoff . The average concentrations of Mn2 + , Sr2 + , K+ , Mg2 + and Ca2 + in throughfall were much higher
than in precipitation as a result of strong interactions with the tree canopy. The average concentration of Pb2 +
in precipitation was as high as 0. 062 mg·L - 1 , indicating some Pb2 + pollution , and it was about 5 times and
10 times higher than that in throughfall and runoff , respectively. This indicated that the Pb2 + in precipitation could be largely absorbed by the tree canopy and soil. The average concentration of Na + gradually increased as
it passed through the ecosystemfrom precipitation (0. 320 2 mg·L - 1) to throughfall (0. 524 7 mg·L - 1) , soil
water at 30 cm (0. 627 3 mg·L - 1) and 80 cm (0. 639 1 mg·L - 1) depth and finally as runoff (0. 629 6
mg·L - 1) . Coefficients of variation of the elemental concentrations in the different solutions ranged from
51. 1 % and 236. 7 %. The average concentrations of those elements in precipitation , throughfall , soil water at
30 and 80 cm depth were higher during the dry season than during wet season , but their concentrations in
runoff during the dry season were lower than or close to that during the wet season. The element Mg had the
highest element-couple correlation as compared to all other elements. The greatest element-couple correlations
were found in throughfall. Correlations among other elements were highly variable. The results show that element nutrient cycles in this forest ecosystem are stable even though under environmental stress.
鼎湖山季风常绿阔叶林水相沉积元素分布及其相关性研究