TREE TUNDRA COMPETITIVE HIERARCHIES, SOIL FERTILITY GRADIENTS, AND TREELINE ELEVATION IN GLACIER-NATIONAL-PARK, MONTANA

被引：43

作者：

MALANSON, GP

BUTLER, DR

机构：

[1] Department of Geography, University of Iowa, Iowa, IA

[2] Department of Geography, University of North Carolina, Chapel Hil, NC

来源：

PHYSICAL GEOGRAPHY | 1994年 / 15卷 / 02期

基金：

美国国家科学基金会;

关键词：

Alpine-treeline ecotone; Glacier National Park; Soil fertility; Subalpine forest; Tundra;

D O I：

10.1080/02723646.1994.10642511

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

The position of treeline has been attributed to climatic factors affecting trees, and some studies mention soils. No studies, however, examine treeline as a limit for tundra vegetation; the treeline is also the tundra-line. The position of treeline on an elevation gradient is examined in relation to soil fertility. Soils were sampled at 25 treeline sites and analyzed for organic fraction, total nitrogen fraction, available phosphorus, and exchangeable potassium. Mean values of N, P,K, organic fraction, and soil depth all are greatest in forest interior samples and least at the tundra samples. Regressions of site elevation on the soil variables show that elevation is negatively related to all variables except phosphorus, but significantly related only to potassium. We applied the centrifugal model of plant community organization and propose that for this ecotone the gradient in biomass is discontinuous and the abruptness of change varies with elevation, moisture, mineral nutrients, nitrogen, disturbance, and slope steepness. The tundra-line may be lower where more nutrients are available because tundra species may more readily alter their competitive ability than do the tree species in this area.

引用

页码：166 / 180

页数：15

共 35 条

[1]

Bamberg S.A., Major J., Ecology of the vegetation and soils associated with calcareous parent materials in three alpine regions of montana, Ecological Monographs, 38, pp. 127-167, (1968)

[2]

Beaudoin A.B., The response of the treeline zone to climatic change in the canadian rocky mountains, Canadian Geographer, 33, pp. 83-86, (1989)

[3]

Becwar M.R., Burke M.J., Winter hardiness limitations and physiography of woody timberline flora, Plant Cold Hardiness and Freezing Stress: Mechanisms and Crop Implications, 2, pp. 307-323, (1982)

[4]

Becwar M.R., Rajashekar C., Hansen-Bristow K.F., Burke M.J., Deep undercooling of tissue water and winter hardiness limitations in timberline flora, Plant Physiology, 68, pp. 111-114, (1981)

[5]

Billings W.D., Alpine vegetation, North American Terrestrial Vegetation, pp. 391-420, (1988)

[6]

Brown D.G., Topographical and biophysical modeling of vegetation patterns at alpine treeline. Unpublished ph.D. Dissertation, Department of Geography, (1992)

[7]

Burns S.F., Tonkin P.J., Soil-geomorphic models and the spatial distribution and development of alpine soils, Space and Time in Geomorphology, pp. 26-43, (1982)

[8]

Butler D.R., Malanson G.P., Periglacial patterned ground, waterton-glacier international peace park, canada and u.S.A, Zeitschrift Fur Geomorphologie, 33, pp. 43-57, (1989)

[9]

Butler D.R., Walsh S.J., Lithologic, structural, and topographic influences on snow avalanche path location, eastern glacier national park, montana, Annals, Association of American Geographers, 80, pp. 362-378, (1990)

[10]

Butler D.R., Lanso G.P., Cairns D.M., Stability of alpine treeline in northern Montana, (1994)

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