Íslenskar landbúnaðarrannsóknir - 01.09.1982, Qupperneq 69

SPRING GRAZING 67
Agricultural Experiment Station Research Bul-
letin Number 80, 128 p.
Haloway, J.G., and Ward, R. T. 1965. Phenology of
alpine plants in northern Colorado. Ecology
46:72-83.
Hodgkinson, K.C., and Baas Becking, H. G. 1977.
Effect of defoliation on root growth of some arid
zone perennial plants. Australian Journal of
Agricultural Research 29:31—42.
Jameson, D.A. 1963. Responses ofindividual plants
to harvesting. Botanical Review 29:532-594.
Jónsson, K. 1974. Vorbeit — áhrif á uppskeru.
Fjölrit frá Ráðunautafundi B.í. og Rala, 6 bls.
Mattheis, P.J., Tieszen, L. L., and Lewis, M. C.
1976. Responses of Dupontia Jisheri to simulated
lemming grazing in an Alaskan arctic tundra.
Annals of Botany 40:179-197.
May, L.H. 1960. The utilization of carbohydrate
reserves in pasture plants after defoliation.
Herbage Abstracts 30:239-254.
McCarty, E.C., and Price, R. 1942. Growth and
carbohydrate content of important mountain
forage plants in central Utah as affected by
clipping and grazing. United States Depart-
ment of Agriculture Technical Bulletin 818,
Washington, D.C., 51 p.
McCown, B.H., and Tieszen, L. L. 1972. A compa-
rative investigation of periodic trends in
carbohydrate and lipid levels in arctic and
alpine plants. Proceedings 1972 United States
Tundra Biome Symposium, p. 40—45.
McNaughton, S.J. 1979. Grazing as an optimization
process: Grass-ungulate relationship in the
Serengeti. Amerian Naturalist 113:691—703.
Menke,J.YJ. and Trlica, M.J. 1983. Effects of single
and sequential defoliations and the reserve
status of four range species. Journal of Range
Management (in press).
Miller, P.C., Stoner, W. A., Tieszen, L. L., Allessio,
M., McCown, B., Chapin, F. S., and Shaver, G.
1978. A model of carbohydrate nitrogen, phos-
phorus alloccation and growth in tundra pro-
duction. In L. L. Tieszen, ed., Vegetation and
production ecology of an Alaska arctic tundra.
Springer-Verlag, New York, p. 577-598.
Mitchell, W. M. 1979. Iceland: Productive north-
land. Agroborealis 11:28-31.
Mooney, H. A., and Billings, W. D. 1960. The
annual carbohydrate cycle of alpine plants as
related to growth. American Journal of Botany
47:594-598.
Mooney, H. A., and Billings, W. D. 1965. Effects of
altitude on carbohydrate content of mountain
plants. Ecology 46:750-761.
Mueggler, W. F., 1972. Influence of competition on
the response of bluebunch wheatgrass to clipp-
ing. Journal ofRange Management 25:88-92.
Mueggler, W. F. 1975. Rate and pattern of vigor
recovery in Idaho fescue and bluebunch wheat-
grass. Journal of Range Management 28:198-
204.
Owensby, C. E., Paulsen, G. M., and McKendrick, J.
D. 1970. Effect of burning and clipping on big
bluestem reserve carbohydrates. Journal of
Range Management 23:358-362.
Óskarsson, M. 1982. Beit á ræktað og óræktað
mýrlendi. Freyr 78:683-689.
Pearsall, W.H. 1950. Mountains and moorlands.
Collins, London 312 p.
Reynolds, H.G., and Martin, S. C. 1968. Managing
grass-shrub cattle ranges in the southwest.
United States Department of Agriculture Hand-
book 162.
Scott, D., and Billings, W. D. 1964. Effects of
environmental factors on standing crop and
productivity of an alpine tundra. Ecological
Monographs 34:243-270.
Smimov, V. S., and Tokmakova, S. G. 1971. Pre-
liminary data on the influence of different
numbers of voles upon the forest tundra vegeta-
tion. Annales Zoologici Fennici 8:154—156.
Smirnov, V. S., and Tokmakova, S. G. 1972.
Influence of consumers on natural phytocenoses
production variation. In F. E. Wielgolaski and
T. Rosswall, eds., Tundra Biome Proceedings
IV, International Meeting on Biological Pro-
ductivity of Tundra. Leningrad, USSR, p. 122-
127.
Smith, D. 1964. Winter injury and the survival of
forage plants: A review. Herbage Abstracts
34:203-209.
Smith, D. 1975. Trends of nonstructural carbohy-
drates in the stembases of switchgrass. Journal
of Range Management 28:389-391.
Spetzman, L. A. 1959. Vegetation of the arctic slope
of Alaska. United States Geological Survey
professional Paper Number 302(B), p. 19-58.
Stoddart, L. A., Box, T. W., and Smith, A. D. 1975.
Range management. McGraw Hill Book Gom-
pany, New York, 532 p.
Stickler, G.S. 1961. Vegetation and soil condition
changes on a subalpine grassland in eastern
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