共查询到20条相似文献，搜索用时 46 毫秒
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Sulphur isotope abundances demonstrate that natural emissions of biogenic H2S and its oxidation products from springs near Paige Mountain, N.W.T., Canada, can be incorporated into surrounding soil and vegetation. δ34S values as low as ? 33‰ for soil and vegetation are the result of dominant uptake of biogenic atmospheric compounds. In contrast, vegetation on a gypsum outcrop remote from the springs, has δ34S values as high as + 26‰ indicating nearly exclusive derivation of S from the soil. Near the springs, soil with vegetative cover is less depleted in 34S than soil lacking cover. Lower needles on a Black Spruce were found to be less depleted in 34S than the upper needles. These observations suggest that upper foliage exerts a canopy effect on lower foliage and in turn, interception by vegetation reduces the flux of atmospheric S compounds to the soil. Clearly, natural emissions of S compounds can interfere in studies of long range transport of industrial emissions; S isotope analyses might identify such interferences and reduce the chance of misinterpretation. 相似文献
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Dr. P.J. Ryan 《CATENA》1993,20(6)
Soil development on Wallagaraugh Adamellite has been studied within Yambulla State Forest, southeastern Australia. Twenty-five soil profiles have been described and soil chemical and physical properties determined for selected horizons. A geomorphological model is described for elucidating processes affecting soil development on this adamellite parent material. Three main geomorphic environments have been incorporated into this model: residual surfaces found on interfluves and broad hillcrests, transportational surfaces associated with ridges and hill slopes, and depositional surfaces associated with foot-slopes and valley floors. Residual surfaces have developed duplex primary profile forms (yellow podzolics) with structured B horizons of high clay content where exchangeable Al dominates the exchange complex. Transportational surfaces have soils with shallow, uniform to gradational profiles with minimal profile development, and highest, but most variable, concentrations of the exchangeable Ca, K, Na, and total P. Depositional surfaces are characterized by a thick accumulation of uniform, coarse-sandy colluvium-alluvium. Where this surface is stable and well drained, podzols have formed. In contrast, areas of impeded drainage on this depositional surface have humic gley profiles. Concentrations of total P, exchangeable Ca and Mg are low throughout these aggraded soils.The soil-landscape units derived from the geomorphological model are discriminated by multivariate analysis using soil chemical and physical properties. Surface soil chemical properties are shown to be superior in discriminating soil-landscape units to subsoil properties.The mineralogy, geochemistry and texture of the adamellite soil parent material are critical in determining the distinctive geomorphology which, in turn, affects the development of soils in this forest environment. 相似文献
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D. W. Schindler 《Water, air, and soil pollution》1989,47(1-2):175-177
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L. Leita M. De Nobili G. Pardini F. Ferrari P. Sequi 《Water, air, and soil pollution》1989,48(3-4):423-433
Samples of soils and vegetation from the mining area of South-West Sardinia (Italy) were analyzed for Pb, Zn, Cd, and Cu content. The area (more than 100 km2) is inhabited by many thousands of people; land utilization includes mainly grapes on some small plains and permanent sheep pasture on the hills. The levels of Pb, Zn, and Cd were found to be exceptionally high in most samples. Lead concentration was up to 71000 μg g?1 in the soils and 4000 jig g?1 in vegetation; Cd concentration was found up to 665 μg g?1 in soils and 26.5 μg g?1 in vegetation. The heavy metal content of some soil samples was highly variable. Data show that Pb is easily absorbed by plant roots and translocated to foliage. In spite of the high heavy metal level, no signs of toxicity were apparent in vegetation. 相似文献
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A. Luchli 《植物养料与土壤学杂志》1978,141(1):123-123