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Forage Production on Important Rangeland Habitat Types in Western Montana

1981; University of Arizona; Volume: 34; Issue: 5 Linguagem: Inglês

10.2307/3897900

2162-2728

Walter F. Mueggler, W. L. Stewart,

Archaeology and Natural History

Peak standing crop and its variability were evaluated over B 3-year period on 35 sites representing 13 important grassland and shrubland habitat types in western Montana.Average production ranged from slightly over 600 kg/ha on the least productive habitat type to 2,900 kg/ha on the most productive.Good sites seldom produced more than twice as much as poor sites within the same habitat type.Although PS much as 2% times more herbnge was produced on a site during the high year than during the low year, the maximum yearly dilference for all sites averaged only 1% times greater.Variation of vegetation classes and factors contributing to production differences are discussed.The potential oi different rangeland sites ior producing forage differs greatly in the highly varied environment of the northern Rocky Mountains (Fig. I).These differences inforagcproductian.coupled with observed differences in other range values and responses to management activities, have stimulated efforts to identify and classify rangeland units according to their inherent capabilities.Much oithe recent thrust in wildland classification in the West has focused on the habitat type concept (Daubenmire 1968; Piister 1976).A classification using this concept has been developed recently for the nonforested rangelands in the mountainous western third of Montana (Mueggler and Stewart 1980).Once such a classification has been developed, however, resource parameters related to the classification units need to be defined.Quantification of resource values is essential to land management planning.Forage, of course, is generally accepted as the principal product to be derived from much of our western rangelands.Forage production on native rangelands in the West is noted for its variation from year to year because of yearly weather differences, and for its variation from place to place because of basic enwronmental differences.Knowledge of the average iorageproducingcapabilities oia given range typeand ofthefluctuations around this average caused by yearly weather variations is fundamental ior planning long-term grazing capacities.The need ior information about forage potentials and variability an western Montana rangeland habitat types prompted the cooperative study between the Forest Service's (Northern)Region 1 and the Intermountam Forest and Range Experiment St&on, results of which are reported here.