Fescue Grassland Research Articles

Supplement to the Lepidoptera of the Mackenzie Country with recommendations on their conservation

Thirty-three species of Lepidoptera in addition to those listed in Patrick (1989b), are recorded from the Mackenzie Country, Canterbury. Sampling was carried out in shrublands, kettle-holes, wetlands, fescue grassland, sandy areas and depleted cushion vegetation. Several species, including Paranotoreas fulva (Hudson), a species characteristic of Central Otago salt-pans, were recorded from the Mackenzie Country for the first time. The uncommon grasshopper Sigaus minutus Bigelow, was found in a number of sites, many of which have substantial populations of the species. Saline soils and an attendant halophytic flora are recorded for the first time from the Mackenzie Country, from a site between Omarama and Otematata. Key conservation sites for the Lepidoptera of the Mackenzie Country are listed and discussed. Some management objectives are put forward.

Grazing impacts on soil water in mixed prairie and fescue grassland ecosystems of Alberta

Reduced soil water under grazing is generally attributed to reduced infiltration as livestock trampling compacts the soil surface. Grazing can also have the opposite effect on soil water through reduced evapotranspiration when vegetation is removed. On the Canadian Prairies, grazing impacts on soil water have been assessed in short-term studies but impacts of long-term grazing have not been documented. In this study, impacts of long-term grazing on soil water were assessed in mixed prairie, parkland fescue grassland, and foothills fescue grassland ecosystems of southern and central Alberta. Grazing regimes were of light to very heavy intensities, grazed early, late, and continuously during the growing season. Soil water was measured with a neutron probe to a depth of 1 m from April through October over three growing seasons. Normal patterns of soil water recharge in autumn and spring and soil water depletion in summer due to evapotranspiration were not altered by grazing. Fluctuations in soil water were most pronounced in the uppermost 30 cm but still evident in the 30- to 50-cm and 50- to 80-cm depth intervals. Heavy intensity and/or early season grazing had a greater impact on soil water than light intensity and/or late season grazing. Season of grazing affected soil water more under light than heavy grazing intensities. On most sampling dates, soil water in grazed treatments was lower than in the ungrazed control, particularly in the 30- to 50-cm and 50- to 80-cm depth intervals. Differences between the control and grazed treatments were least pronounced during the summer months with evapotranspiration depleting soil water reserves in all treatments. Key words: Soil water, grazing, rangelands, water uptake

Water Holding Capacity of Litter and Soil Organic Matter in Mixed Prairie and Fescue Grassland Ecosystems of Alberta

Litter and organic matter accumuiations can reduce soil water through interception of precipitation and subsequent evaporation of absorbed water. Interception varies with mass and water hoiding capacity (WHC) of litter and organic matter, and is highest from small precipitation events. WHC varies with vegetation type, which is affected by grazing regime. Thus long-term grazing could affect WHC of litter and organic matter and would be important in the hydrologic assessment of rangelands subjected to many small precipitation events throughout the growing season. The study was conducted in mixed prairie, parkland fescue, and foothills fescue grasslands in Alberta, Canada. Grazing regimes were of light to very heavy intensities, grazed early, Me, and continuously during the growing season. Litter and organic matter were sorted by sieving into various sized categories. Litter-soil cores were also evaluated. WHC of litter and organic matter was lower in mixed prairie than in fescue grasslands. WHC increased with increazed particle size, being higher for roots and standing and fallen litter than for organic matter. WHC of iarge particle-sized material decreased with heavy intensity and/or early season grazing. WHC was affected more by intensity than season of grazing. Grazing affected WHC through species composition changes, since species have different WHC, and through trampling which affected particle size. It was concluded that litter and organic matter WHC were important in rangeland hydrologic assessments.

Applicability of the Kostiakov Equation to Mixed Prairie and Fescue Grasslands of Alberta

The Kostiekov equation is of interest in rangeland hydrology because it is a simple 2 prrnmeter equation with values of constants easy to determine from measured infiltration data, and because of its reasonable fit to infiltration data for many soils over short time periods. There is, however, some controversy in the literature regarding its applicability to rangelands. The Kostiakov infiltration equation was examined to determine its suitability to characterize hrfiltration on mixed prairie and fescue grassland ecosystems in Alberta, Canada. The infiltration data from double ring infiltrometers fit the Kostiakov equation very well. Of 26 regressions, 10 had anRr over 0.95 while another 8 had an R* over 0.90. The average R2 for all data at a site was 0.931 for mixed prairie, 0.857 for parkland fescue, and 0.938 for foothills fescue grassland. Changes in antecedent soil water and different grazing regimes altered the 2 equation parameters. Intercepts consistently declined with intensity and earliness in the growing season of grazing, although there were no consistent treatment trends with grazing. The Kostiakov equation is considered a good equation for infiltration in the 3 grassland ecosystems studied. Although parameter m had a narrow range of values for all 3 ecosystems and an average value from this study could be used, parameter a limits the equation and field testing is required for its determination.

Cutting Frequency and Cutting Height Effects on Rough Fescue and Parry Oat Grass Yields

A study was made in the Rough Fescue Grasslands of southwestern Alberta to determine the yield response of rough fescue (Festuca scabrella var campestris Rydb.) and Parry oat grass (Danthonia parryi Scribn.) to 5 cutting frequencies and 3 heights over a Iyear period. The same plants were cut either 1,2,4,8, or 16 times over a U-week period beginning in mid-May, at 16, &, 4, 2-, or l-week intervals, respectively, and at heights of either 5, 10, or 15 cm above ground level. Yield response to cutting treatments differed significantly from the flrst to the third treatment year. In the first year, rough fescue and Parry oat grass produced most forage when cut at a height of 5 cm with 1,2, or 4 cuts. By the third year, rough fescue produced the greatest yields with a single cut after 16 weeks and Parry oat grass produced the greatest yields when cut at 10 or 15 cm at I-week intervals. The data confirm the high sensitivity of rough fescue to grazing while the plant is growing and suggest that the greatest benefit from the Rough Fescue Grasslands may be derived by grazing in fall or winter. Summer grazing favors Parry oatgrass, which is more tolerant than rough fescue, but forage production on the grassland is reduced.

Grazing Impacts on Litter and Soil Organic Matter in Mixed Prairie and Fescue Grassland Ecosystems of Alberta

Grazing Impacts on Litter and Soil Organic Matter in Mixed Prairie and Fescue Grassland Ecosystems of Alberta

GRAZING IMPACTS ON INFILTRATION IN MIXED PRAIRIE AND FESCUE GRASSLAND ECOSYSTEMS OF ALBERTA

Infiltration capacity is generally reduced with increased grazing intensity and reduced range condition, mainly through vegetation and litter removal, soil structure deterioration, and compaction. Only one study has documented the effect of grazing on Canadian rangelands, necessitating further investigation. In this study, impacts of long-term grazing on infiltration were assessed in mixed prairie and fescue grassland ecosystems of southern and central Alberta, Canada. Grazing regimes were of light to very heavy intensities, grazed early, late, and continuously during the growing season. Ungrazed controls were evaluated at each site. Infiltration was measured with double ring infiltrometers. Heavy intensity and/or early season grazing had greater impact on infiltration than light intensity and/or late season grazing. In mixed prairie, initial and steady state infiltration rates in the control were 1.5 and 1.7 times higher, respectively, than those in the early season grazed treatment. In parkland fescue, initial rates were lowest in June grazed treatments and steady state rates were highest in light autumn grazed and control treatments. Initial infiltration rates in foothills fescue control and light grazed treatments were 1.5–2.3 times those in heavy and very heavy grazed treatments. Steady state rates were 1.5–2 times higher in light grazed and control treatments than in moderate, heavy, and very heavy grazed treatments. Key words: Infiltration, infiltration rate, grazing, rangelands

SOIL COMPACTING IMPACTS OF GRAZING IN MIXED PRAIRIE AND FESCUE GRASSLAND ECOSYSTEMS OF ALBERTA

The impacts of long-term grazing on compaction were assessed in mixed prairie and fescue grassland ecosystems of Alberta. Grazing regimes were of light to very heavy intensities, grazed early, late, and continuously during the growing season. Bulk density was measured with a surface moisture/density gauge and a combination moisture/density probe to 65 cm. Penetration resistance to 30 cm was measured with a cone penetrometer. Solonetzic soils were less sensitive to compaction under grazing than Chernozemic soils. Heavy intensity and/or early season grazing had greater impacts on compaction than light intensity and/or late season grazing. Under the former grazing regimes, bulk density increased to 7.5 cm at Kinsella and 65 cm at Stavely; penetration resistance increased to depths of 2.5 cm at Brooks, 15 cm at Kinsella, and 30 cm at Stavely. Heavy trampling versus regular grazing increased penetration resistance to depths of 30 and 10 cm under heavy intensity and/or early season and light intensity and/or late season grazing, respectively. Late season grazing at Brooks and light to moderate grazing at Stavely may be used as management models to reduce compaction under grazing. Trends were not as clear at Kinsella, but light June and autumn grazing had the least compacting effect. Key words: Compaction, grazing, rangelands, penetration resistance, bulk density

Ecology of Fescue Grasslands in Glacier National Park

Fescue grasslands are important habitat types within several drainage systems in Glacier National Park. A two year field study (1989, 1990) was undertaken to assess factors potentially threatening the integrity of these grasslands. Objectives of this study are to: 1. Identify factors determining the distribution of fescue grasslands; 2. Describe plant and vertebrate communities inhabiting fescue grasslands; 3. Identify factors that are potentially disruptive to the natural integrity of fescue grasslands; and 4. Develop a management model that includes hypotheses to be tested by management actions. Field work for both first and second seasons has now been completed and data analysis is in progress.

Distribution of Nitrogen Fractions in Grazed and Ungrazed Fescue Grassland Ah Horizons

AbStUCt Grazing affects the plant ecology and adds cxcreta, thereby lnfluenclng soll N relatlonshfps. Consequently, total N, mlnerallxable N, exchangeable N, hydrolyxable N, and urease activity were assessed at the Agriculture Canada Research Substation, Stavely, Albert8, in the Ah horizons on rough fescue (F&ucu scafueI& Ton.) grasslands stocked at either light (0.8 ha/AUM) or very heavy (0.2 ha/AUM) fixed rates for 38 years and in exclosurea located within each field for an equal period of time. Even though total N expressed as t/ha per Ah horizon remained the same, changes in various N fractions were nevertheless evident. Graxing resulted in more NH&N and NO&N in both fields at the time of sampling and each was greater at the higher stocking rate. Although soll N was less mfneralixable, it was more acidhydrolyxable at the nigher stocking rate. Urease activity also increased. The effect on soll N charrcteristics of increased excretr

Vegetation and Soil Responses to Short-Duration Grazing on Fescue Grasslands

The effects of animal impact on soil chemical and physical properties as well as range condition were measured over a 5-year period to test tbc bypotbesls that animal impact can improve the nutrient and water status of the soil and promote grassland succeadon. A seventeen-pasture short-duration graxing system was establlsbed in 1981 on 972 ba. The pastures were stocked on average wltb 278 cows wltb calves from 1982 to 1986, wbicb was about twice to triple tbe recommended rate of 0.8 AUM/ba. Increased grazing pressure reduced range condition as reflected by a loss of de&able species such as rougb fescue (Festuccr scubrelkh Torr.). Soil molsture was always bigber in soils of ungrazed exclosures. Soli bulk density increased wblle hydraulic conductivity decreased with grazing. Litter was not signlflcantiy incorporated into the soll with hoof action. Cbltln-N, as a measure of fungrl biomass, decreased significantly under tbe increased grazing pressure. Tbe bypotbesis that animal impact would improve range condition was rejected since impact, in tbe manner applled during tbe study, resulted ln retrogression of the grasslands.

Ecology of Fescue Grasslands in Glacier National Park

Fescue grasslands are small, but ecologically significant, habitat types in several drainages within Glacier Park. An up-to-date, systematic study of the plant and animal communities of these grasslands is needed to assess factors which may potentially impact these habitats, including invasion of exotic vegetation, fire suppression, and human development (e.g. sewage line and road construction).

Stability of Grazed Patches on Rough Fescue Grasslands

cootiouous stockiog usu8Ily leads to the fonlutioo of grued patclkea. However, the effect of p&bee 00 the grazelMd c0mmunity is related to their stability. Therefore, we ztudied the spatial stability of grazed pat&e oo Rough Fezcue Gramlande by map ping forage remov8l clmuee 00 10 site8 over 8 Cyeu period, tezting stability uzing the Kappa index (H), and characterizing the soila and vegetatioo of overgrazed and undergrazed patches. Spotlal stability of grazed patches between comecutivc yeam wm good (lEO.26) oo &en experieming low grazing prwsure. However, oo dtea having high grazing preezure, spatial stability waz Iese comizteot between comecutive yeuz (DKSO.45) ud low over 8 Cyeu period (K10.10). Overgrazed patches were dominated by graziogresistant zeral speck, but undergrazed patcher were dominated by climu species. Rough feecue (%cstuco SC&&~ 8nd P8rry oat grazs @u&to& porryi) plantz were 50% shorter, and forage production waz about 35% lees, on overgrazed than on undergrazed patches. Soil organic matter, carbohydratea, and depth of Ah horizon were zignificantly greater oo undergrazed patches but ureaze activity, NO& NH,, and available phosphorus were greater oo overgrazed patchez. Overgrazed and undagrazed patches were stable in the long term, although patch bouodariez fluctu8ted.

FORAGE PRODUCTION AND UTILIZATION IN VARIOUS TOPOGRAPHIC ZONES OF THE FESCUE GRASSLANDS

The effects of topography and litter on forage production and utilization were studied on Rough Fescue Grasslands in the foothills region of southwestern Alberta. Forage production and utilization were estimated, at monthly intervals during the grazing seasons over 4 yr, in six topographic zones of two fields stocked at a moderate or a high rate representing 2.4 or 3.2 animal unit months per hectare (AUM ha−1), respectively. The higher rate could not be achieved in the first 3 yr of the study because available forage was limiting. The topographic zones were represented by the west, east, south, and flat aspects of the upland areas, and by the lowland zone subdivided into a subirrigated zone and the interface between the latter and upland zones. Forage production was about 50% more in the subirrigated zone than in the upland zones. Among the upland zones, forage production tended to be greatest on the south aspect. Forage utilization was greatest in the subirrigated zone but least on the south aspect. Topographic preference was highest for the subirrigated zone early in the grazing season. The effect of a high stocking rate was to minimize the preference differences among topographic zones. Litter had a significant positive effect on both forage production and the amount of residual forage after the grazing season but had a significant negative effect on percent utilization. Litter provided a buffer which enabled the maintenance of anticipated stocking rate by providing emergency forage and enhancing production during drought. Key words: Litter, residual forage, preference, aspect, stocking rate, cattle, distribution

Douglas-Fir Encroachment into Mountain Grasslands in Southwestern Montana

A study of plant succession in relation to disturbance history was conducted in Douglas-fir [Pseudotsuga menziesii var. glauca (Beissn.) Franco] forest and fescue (Festuca L. spp.) grassland communities along the eastern slope of the Continental Divide in Montana. The objective was to obtain ecological information needed for assessing management alternatives aimed at enhancing big game habitat and livestock forage. Fire history was reconstructed through analysis of fire scars and age classes of trees. Sizes and ages were inventoried in sapling stage, pole stage, and mature forest stands. Results indicate that prior to 1890 fires occurring every few decades favored grassland and confined tree growth to rocky or topographically moist sites. Since 1890 fires have been rare as a result of livestock grazing (which removes fine fuels), fire suppression, and cessation of ignitions by Native Americans. Lack of fire allowed extensive areas of Douglas-fir now of pole size to become established in former grasslands between 1890 and 1915. Widespread invasion of sapling size trees occurred between 1941 and 1955, when seed crops apparently coincided with unusually favorable moisture conditions. For management of these areas, we recommend use of prescribed fire in conjunction with timber harvesting to enhance declining forage productivity for big game and livestock. Previously, we reported that Douglas-fir [Pseudotsuga menziesii var. glauca (Beissn.) Franco] forests have expanded and thickened near the lower timberlines in southwestern Montana (Arno and Gruell 1983, Gruell 1983). In this paper we present information on the magnitude of Douglas-fir encroachment in mountain grasslands in a study area representative of this region. We examine the relationship of fire history to changes in age-class and size-class structure in both and old-growth forest stands, occurring on different forest habitat types (potential climax). Douglasfir is invading sites that were previously maintained as grasslands by periodic fires. In 1983, a prescribed fire demonstration area was established on the Galena Allotment, Deerlodge National Forest, to test prescriptions for managing east-side Douglas-fir forests and mountain grasslands. Objectives were to enhance wildlife habitat (primarily for elk, Cervus elaphus L., and mule deer, Odocoileus hemionus Rafinesque), improve forage for livestock, and reduce wildfire hazard. National Forest and research personnel had observed the spread of Douglas-fir into mountain grasslands on the Galena area and recognized that continued tree encroachment would reduce forage production. However, there was a lack of detailed information on the ecological background of this invasion. Nearby oldgrowth Douglas-fir forests were dense, decadent, and contained little forage. These stands contained dying remnants of quaking aspen (Populus tremuloides Michx.) groves and overmature seral shrubs, indicating that they had previously supported considerable browse. S. Arno is a research forester in the Prescribed Fire and Fire Effects Research Work Unit of the Intermountain Research Station, Forest Service, U.S. Department of Agriculture, located at the Intermountain Fire Sciences Laboratory, Missoula, Mont. 59807. At the time this study was conducted, G. Gruell was a research wildlife biologist in the same unit; he is currently regional fuels management officer, Intermountain Region, Forest Service, Ogden, Utah 84401. The authors are indebted to personnel of the Deerlodge National Forest for their assistance during this research effort, and to the following reviewers for their helpful comments: Stephen Barrett, Systems for Environmental Management, Missoula; Wendel Hann, Northern Region, USDA Forest Service; Richard Laven, Colorado State University; Walt Mueggler, Intermountain Research Station. USDA Forest Service; Earl Willard, University of Montana; and two anonymous referees. Manuscript accepted 29 August 1985. We conducted a brief study of the Galena area to collect quantitative information concerning plant succession relative to disturbance history. This information was needed as an ecological basis for assessing management alternatives, including tree harvesting and possible conversion back to open forest, savanna, or grassland. Such practices might also be applicable to other Douglas-fir and mountain grassland areas, which are widespread in the Northern Rockies.

Cattle Weight Gains in Relation to Stocking Rate on Rough Fescue Grassland

Cattle Weight Gains in Relation to Stocking Rate on Rough Fescue Grassland

Thematic Mapper Data Used for Rangeland Management in Rough Fescue Grasslands in Western Canada

RESUMEEn 1984, le Centre canadien de teledetection, le Ministere de l'Energie et des Ressources de l'Alberta ainsi que le Centre albertain de teledetection entreprenaient conjointement un projet visant a evaluer le degre d'application des donnees du capteur Thematic Mapper (TM) pour la gestion des pâturages.Les donnees de terrain et de teledetection ont ete acquises dans une region de prairies a fetuque scabre situee en Alberta, a quatre dates differentes au cours de la saison du pâturage. Les differents parametres mesures au sol, dans les pâturages echantillonnes, comprenaient, d'une part, le pourcentage de couverture du sol par la vegetation active (verte), la vegetation senescente (brune) et par le sol nu et, d'autre part, la biomasse des graminees, des residus vegetaux et des dicotyledones herbacees. Une serie de cliches a egalement ete prise sur chaque site-temoin lors des passages de LANDSAT 5.Les donnees TM correspondant a chacune des dates ont ete corrigees pour les differences d'angle d'elevation...

Effects of Stocking Rate on a Rough Fescue Grassland Vegetation

their construction, to a stable range condition, took from 14 years in the lightly grazed field to more than the length of the study in the A study was conducted to examine the effects of 4 stocking rates on the vegetation in a Rough Fescue Grassland vegetation in southwestern Alberta. Stocking at a light rate (1.2 AUM/ha) for 32 very heavily grazed field. The duration required for recovery was years did not affect range condition. However, a modest increase in stocking rate (1.6 AUM/ha) led to a marked decline in range related to the original range condition of the exclosures. condition. This was associated with a change in the composition of rough fescue from 38 to 21% of basal area. Rough fescue (FestzCQ ScQbreflQ) was nearly eliminated with a stocking rate of 2.4 AUM/ha. Rough fescue was repiaced by Parry oat grass (DQnthoni~ parryi) which increased from 24% at 1.2 AUM/ha to 48% at 2.4 AUM/ha. However, stocking at 4.8 AUM/ha resulted in severe deterioration of the grassland. This required annual adjustment of the stocking rate to avoid animal losses. The recommended stocking rate for good condition range in the area is 1.6 AUM/ha. Recovery of the vegetation within the exclosures, from the time of setting stocking rates. The stocking rate, expressed in this paper as animal unit months per hectare (AUM/ ha), defines the relative quantity of forage that will be harvested during the grazing period in a given year. The effect of increasing the stocking rate is to increase the proportion of forage utilized, which may lead to changes in species composition of grasslands (Ellison 1960). The species that increase because of an increased stocking rate are often sub-dominants in the plant community and are potentially less productive than the dominant species (Looman 1969). The purpose of this study was to examine the changes that occur in species composition of a Rough Fescue Grassland as a result of stocking with cattle at different rates. The work described is part of a final assessment of the study which was reported earlier (Johnston 1961, Peake and Johnston 1965).

Rough Fescue Response to Season and Intensity of Defoliation

Rough fescue (Festuca scabrella Torr.) was subjected to 10 clipping regimes which varied in time or intensity of defoliation. The experiment was repeated at 2 sites for 3 consecutive years. Plant survival and vigor were evaluated the summer following defoliation. Clipping treatments involving weekly defoliation to a 5-cm stubble height from mid May to late June resulted in the greatest injury. Reduced injury occurred when clipping ceased in May or when 10 or 15 cm of herbage was retained. Season long defoliation to 20 cm or clipping only in the fall caused no apparent damage. Cutting in the fall plus spring resulted in greater injury than spring clipping alone on plants clipped from mid May to late June but a fall clipping effect was not observed consistently on plants clipped in May plus fall. Despite common observances of rapid decline of rough fescue (Festuca scabrella Torr.)' on overgrazed ranges, little work has examined defoliation response of this productive grass. Root and top growth yields were reduced by repeated monthly clipping to stubble heights of 4(1l/2), 7.5(3), or 12.5(5) cm (inches) in a greenhouse study (Johnston 1961). Magnitude of root yield reduction from the 12.5-cm treatment (comparable to 20% utilization) was much greater than reduction in herbage yield. Tiller production was depressed with the 2 most severe treatments but apparently was unaffected by the 12.5-cm stubble height treatment. The author advised caution in interpretation of clipping trials since 20% utilization on an Alberta fescue grassland indicated no depression of root or herbage yields. A long-term study (Johnston et al. 1971) showed that even light season-long grazing (0.8 ha/AUM) reduced rough fescue basal area after 16 years and the species was largely eliminated under very heavy grazing (0.2 ha/ AUM). Long-term consequences of a grazing trial could not be determined after 6 years on a central Albertan rough fescuewestern porcupine grass (Stipa spartea Trin.) rangeland (Bailey et al. 1980) but heavy (75%) utilization in either June or fall depressed grass production. Light (35%) utilization results were similar to the controls. Fescue yields the year following mowing in another Alberta study (Sinton and Bailey 1980) were greater than the control for the April 8 treatment; but cutting late in spring (April 27, June 1) or in fall (July 31, Oct. 18) resulted in production losses. Tiller density increased and leaf length decreased for all mowing treatments but the effects were most pronounced for the fall cuttings. Of the spring mowing treatments, leaf lengths were shortest and tiller stimulation was slightest for the June 1 mowing. In a previous paper, Stout et al. (1981) examined vegetative and reproductive growth of rough fescue. In the present study, response of rough fescue to a number of clipping regimes incorporating different times, frequencies and intensities of defoliation is compared.

Changes in Diets of Wapiti during a Hunting Season

Changes in Diets of Wapiti during a Hunting Season