13 research outputs found
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Miserotoxin Levels In Fertilized Astragalus miser var. serotinus
The effect of fall application of urea fertilizer on toxicity of timber milkvetch was examined in 2 growing seasons at 2 rangeland sites in southern British Columbia. On the grassland site, aerial application of urea at 100 kg N/ha did not affect levels of miserotoxin in timber milkvetch. At the forest clearcut site, 200 kg N/ha reduced toxin levels at later stages of growth in the first growing season. In the second year, however, an increase in the level of miserotoxin was detected at the clearcut.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
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Grazing effects and range trend assessment on California bighorn sheep range
This study investigated the effect of grazing by California bighorn sheep (Ovis canadensis californiana) on plant community structure. Over 28 months from 1977 to 1979, bighorn diet consisted of 79 species, including 14 grasses, 47 forbs and bryophytes, plus 18 trees and shrubs. Grasses, forbs, and shrubs comprised 66.6, 18.9, and 14.5% of the diet, respectively. Three years of bighorn sheep grazing reduced (P < 0.05) leaf and culm lengths of bluebunch wheatgrass (Agropyron spicatum (Pursh) Scribn. & Smith). Grazing generally reduced leaf length, basal diameter, culm (stem) length, and culm (stem) numbers of prairie Junegrass (Koeleria cristata Pers.), Sandberg's bluegrass (Poa sandbergii Vasey), needle-and-thread (Stipa comata Trin. & Rupr.), Thompson's paintbrush (Castilleja thompsonii Pennell), silky lupine (Lupinus sericeus Pursh), and snow buckwheat (Eriogonum niveum Dougl.). Vigor of arrowleaf balsamroot (Balsamorhiza sagittata (Pursh) Nutt.) was unaffected by grazing, despite its dietary importance. Total plant frequency remained unchanged between 1976 and 1983 in areas grazed by bighorn sheep, and in grazing exclosures. Total grass frequency declined from 46.5 to 30.8% within the exclosures, but increased from 44.7 to 48.8% in response to bighorn sheep grazing. Forb frequency remained unchanged after 7 years of bighorn sheep grazing while frequency of yarrow (Achillea millefolium L.) increased more inside exclosures than on the grazed area. Botanical composition of shrubs increased on grazed and ungrazed areas from 1976 to 1983, but frequency was unaffected by bighorn sheep grazing. Snow buckwheat and Wyeth buckwheat (Eriogonum heracleoides Nutt.) declined in response to bighorn sheep grazing. Successional trends caused by California bighorn sheep grazing differed from trends expected from cattle grazing.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
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Prescribed Burning on B.C. Rangelands: The State of the Art
This paper reviews research and experiences up to the present in the use of fire as a rangeland management tool in British Columbia. Although the climate of opinion towards burning is becoming increasingly more favourable, little specific information is yet available to allow precise use of fire for habitat modification. Some results from north-western United States are applicable but these are sometimes contradictory and, not infrequently, incomplete. A program of fire ecology research is outlined which will provide the necessary information to permit the use of fire to achieve specific range management objectives.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
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Phenological patterns and adaptations in an Artemisia/Agropyron plant community
The phenology of 75 plant species belonging to an Artemesia tridentata Nutt./Agropyron spicutum (Pursh.) Scribn. & Smith plant community in southern British Columbia was recorded in 1978 and 1979. Plant species were classified witbin 4 phenological groups that are hypothesized to reflect adaptation to spatial and temporal distribution of soil moisture. Summer Mature taxa (36 species, including 20 perennial forbs and 10 annual grasses and forbs) initiate growth early, fIower rapidly, and mature before or soon after summer drought began. Favorable moisture conditions in the fall may produce some regrowth. Summer Quiescent taxa (27 species, including 8 of 9 perennial grasses) also initiate growth early in spring, develop fairly rapidly, but flower later than Summer Mature taxa, becoming only semidormant during summer drought. Significant regrowth often occurs in response to fall moisture. Protracted Growth taxa (4 species) display delayed spring growth, followed by fall flowering. These deeply rooted shrubs continue to grow and develop slowly throughout the frost-free period. Eight, generally shallowly rooted forbs were classified as Spring Ephemerals that initiate development very early in spring, flower and terminate growth before summer drought, and rarely resprout in fall. These 4 phenological groups provide flushes in botanical composition, forage production, and nutrient availability that should be reflected witbin grazing management and rangeland inventory programs.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
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Effect of forage seeding on early growth and survival of lodgepole pine
Smooth bromegrass (Bromus inermis Leys.), orchardgrass (Dactylis glomerata L.), alsike clover (Trifolium hybridum L.), and a mixture by mass of 40% orchardgrass, 40% alsike clover, and 20% white clover (Trifolium repens L.), were sown at 0.5, 1.5, 3.0, 6.0, and 12.0 kg/ha on a forest clear-cut in the southern interior of British Columbia. The seeding treatments were monitored for 3 growing seasons following planting to determine their influence on the growth, survival and damage of planted one-year old lodgepole pine (Pinus contorta var. latifolia Engelm.) seedlings. Competing vegetation reduced lodgepole pine diameter by up to 38% (P 0.05) among the treatments and controls, and conifer survival was independent (P > 0.05) of rodent damage.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
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Forage response to N, P, and S fertilization on clearcut lodgepole pine sites
The response of selected plant species to a single application of factorial combinations of nitrogen (N), phosphorus (P), and sulfur (S) on 2 lodgepole pine (Pinus contorta Dougl.) clearcut-logged sites in British Columbia was evaluated over 3 years. Increasing N rates typically resulted in higher forage standing crop on both sites, in all years. but standing crop at Fly Creek was nearly double that at Beaverdam Lake. On both sites, forage yields peaked at 400 kg N/ha in 1982 and carry-over of the fertilizer effect lasted for 3 years although yields declined annually. Addition of P to N applications enhanced (P 0.05) on other species and groups. Sulfur, added to N applications, enhanced total yields compared to control on both clearcuts although at Fly Creek this response nearly doubled that produced at Beaverdam Lake. Nitrogen fertilization increased (P < 0.05) pinegrass crude protein (CP) content, particularly in the first year after fertilization. Acid detergent fiber (ADF) generally increased in response to increasing N levels in 1982, but declined compared to control in 1983 and 1984. Elevated forage CP levels, litter N concentrations, and soil N levels in 1984 indicated that the carry-over response on these forest sites resulted directly from N remaining in the soil or again becoming available for plant growth.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
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Effect of fertilization date and litter removal on grassland forage production
The effects of application dates of urea fertilizer and dormant-season removal of litter were examined on a bluebunch wheatgrass (Pseudoroegneria spicatum [Pursh] A. Love subsp. spicata)- Sandberg's bluegrass (Poa sandbergii Vasey) site in southern British Columbia. Forest grade urea, applied at 100 kg N/ha, increased the yield of both spring (53%) and summer (73%) forage compared to the unfertilized control. Spring forage production was not affected by the application date of urea. Summer forage yields, however, were 20% higher when urea was applied on snow-free (October and March) compared to snow-covered ground (November, January, and February). Dormant-season removal of litter reduced spring forage yields by different amounts (P<0.05) in 1984 (29%) and 1981 (25%). Albiet a small difference, this suggests that removal of litter may interact with annual weather conditions and confound measurements of absolute spring herbage yields in a long-term study. In contrast, dormant-season removal of litter reduced summer forage production consistently by 23% in both 1981 and 1984. This technique might therefore be used to reduce clipping time for summer plots in fertilizer trials. If absolute estimates of above ground herbage production are required, control plots should be clipped each year to account for the losses in yields induced by dormant-season removal of litter.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
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Using a grazing pressure index to predict cattle damage of regenerating tree seedlings
This research investigated the potential for using cattle grazing pressure (AU Mg-1 ha-1) and stocking rate (Animal Unit Days ha-1) for predicting basal scarring and browsing of lodgepole pine (Pinus contorta Dougl.) seedlings on cutblocks in southern British Columbia from 1989 to 1992. Cattle browsing on lodgepole pine seedlings occurred almost exclusively during the first 2 years of grazing. Browsing increased (P 10% of sample trees when grazing pressure exceeded 12.0 AU Mg-1 ha-1. This threshold grazing pressure value of 12.0 AU Mg-1 ha-1, however, cannot likely be extrapolated directly to other sites. Grazing pressure values and associated basal scarring are unquestionably influenced by many factors (e.g., pasture size, kind of grazing animal, forage species, tree height, water availability, topography, and weather patterns during the grazing period). Nonetheless, our work provides evidence that grazing pressure provides a useful index for predicting the potential for trampling damage of lodgepole pine seedlings by cattle.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202