SOIL-NITROGEN TRANSFORMATIONS ON A SUB-ANTARCTIC ISLAND

被引：15

作者：

SMITH, VR

STEENKAMP, M

机构：

[1] Department of Botany and Genetics, University of the Orange Free State Bloemfontein

来源：

ANTARCTIC SCIENCE | 1992年 / 4卷 / 01期

关键词：

MARION ISLAND; MINERALIZATION; NITROGEN; NUTRIENT CYCLING; PLANT NUTRIENT UPTAKE; PEAT CHEMISTRY; SUB-ANTARCTIC;

D O I：

10.1017/S0954102092000099

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

The vascular vegetation of a mire-grassland community on Marion Island (47-degrees-S, 38-degrees-E) takes up c. 158 mg N m-2 d-1 in summer. Bryophytes take up c. 36 mg N m-2 d-1 during their peak growth period. Since inputs of N through precipitation and biological fixation are negligible, mineralization of organic N must have supplied the bulk of this N. From changes in peat inorganic N levels and rates of uptake by the vegetation we estimate mean mineralization rates of 178 mg N m-2 d-1 in summer and 55 mg N m-2 d-1 in winter. In situ incubation of peat give a maximum mineralization rate of 48 mg N m-2 d-1. At this rate the small (700 mg m-2) pool of available N in the upper 25 cm of peat would be depleted by the vascular vegetation in about seven days and bryophytes would deplete the available N pool in the top 25 mm in two days. Hence the rate of N mineralization measured by incubation is much too low to account for the fluctuations in concentrations of inorganic N in the peat and the amounts taken up by the vegetation. This may be due to losses through denitrification or to the fact that soil macroinvertebrates were excluded from the incubation.

引用

页码：41 / 50

页数：10

共 30 条

[1]

BERNARD J.M., GORHAM E., Life history aspects of primary production in sedge wetlands, Freshwater wetlands. Ecological processes and management potential, pp. 39-51, (1978)

[2]

BROWN J., VEUM A.K., Soil properties of the international tundra biome sites, Soil organisms and decomposition in tundra., pp. 27-48, (1974)

[3]

BURGER A.E., Terrestrial invertebrates: a food resource for birds at Marion Island, South African Journal of Antarctic Research, 8, pp. 87-99, (1978)

[4]

CLARHOLM M., Interactions of bacteria, protozoa and plants leading to mineralization of soil nitrogen, Biochemistry, 17, pp. 181-187, (1985)

[5]

The role of feral house mice in ecosystem functioning on Marion Island, Ecological change and conservation of Antarctic ecosystems. Proceedings of the 5th SCAR Symposium on Antarctic Biology, pp. 359-364, (1990)

[6]

FRENCH D.D., SMITH V.R., Bacterial populations in soils of a subAntarctic island, Polar Biology, 6, pp. 75-82, (1986)

[7]

GERSPER P.L., ALEXANDER V., BARKLEY S.A., BARSDATE R.J., FLINT P.S., The soils and their nutrients, An Arctic ecosystem. The coastal tundra at Barrow, pp. 219-254, (1980)

[8]

GRIENITZ K.H., KENT L.E., DIOXN R.D., Volcanic ash, ash soils and the inferred Quaternary climate of sub-Antarctic Marion Island, South African Journal of Science, 82, pp. 629-635, (1986)

[9]

GROBLER D.C., TOERIEN D.F., SMITH V.R., Bacterial activity in soils of a sub-Antarctic island, Soil Biology and Biochemistry, 19, pp. 485-490, (1987)

[10]

HARMSEN G.W., KOLENBRANDER G.J., Soil inorganic nitrogen, Soil nitrogen, pp. 43-92, (1965)

← 1 2 3 →