William A. Laycock

How Heavy Grazing and Protection Affect Sagebrush-Grass Ranges.

profession have, or should it have, a policy in regard to the use of plant names? One can easily see that common names add interest and color to a world that would be, for many, coldly scientific and remote if only Latin designations were available. A scientific name usually tells a story, reflecting origin (virginiana), size (gigantea), color (rosea), or form (squarrosa). The same is true of common names, and where they have a useful and significant meaning, some thought should be given to their preservation. A good example is the unfortunate shortening of the Old World “goatfacegrass” to “goatgrass”. The first is descriptive, the second is meaningless. Neither authority nor administration should force upon the literature the common name “centaurea” (cf. Standarized Plant Names) when general usage has brought acceptance to “knapweed” and “starthistle” (see list of Weed Society of America). Acceptance of a standardized list, reserving the right to make changes, is a compromise for both extremes. Range science needs common

Repeat photography on range and forest lands in the western United States.

Repeat photography is a valuable tool for demonstrating the effects over time of climate, management and other variables on range and forest lands. This bibliography lists 175 publications using repeat photography, with information on the ecosystems photographed, states where they are located, number of photographs, and dates when the photographs were taken. References to photography of 19 natural ecosystems, 2 cultivated ecosystems and 3 special problems are listed. The interval between photographs may be over a century or less than a year.

Effect of Grazing on Soil Compaction as Measured by Bulk Density on A HIgh Elevation Cattle Range.

ful establishment of Sherman big bluegrass were studied at the Manitou Experimental Forest, Colorado, from 1963 to 1965. Recommendations for seeding areas having similar soil and climatic conditions are as follows: 1. Sherman big bluegrass should be planted into a moist seedbed in July or August. The seedlings can be expected to emerge 7 to 10 days after planting and be well established within 2 to 3 months. Bluegrass emergence is poor if the seed must remain in the ground for a prolonged period of time. Although spring seeding is less favorable, it is a possible alternative providing soil moisture is good. 2. On sandy-loam or sandyclay-loam soils, seed should be drilled as uniformly as possible to a 0.5or 5/%-inch depth. Five pounds per acre at a maximum 12-inch row spacing is a suggested seeding rate. A doubledisc, depth-band or comparable grass drill is recommended for controlling seed placement depth. 3. Leave the soil rough plowed until just prior to seeding to reduce the establishment of weeds and the interval the ground is susceptible to erosion.

Three methods of determining diet, utilization, and trampling damage on sheep ranges.

GARRISON, G. A. 1953. Effects of clipping on some range shrubs. J. Range Manage. 6:309-317. HOLMGREN, A. H., AND J. L. REVEAL. 1966. Checklist of the vascular plants of the Intermountain Region. U.S. Forest Serv. Res. Paper INT.-32. 160 p. HORMAY, A. L. 1943. Bitterbrush in California. U.S. Forest Serv., Calif. Forest and Range Exp. Sta. Res. Note 34. 12 p. LAYCOCK, W. A. 1967. How heavy grazing and protection affects sagebrush-grass range. J. Range Manage. 20:206213. NEFF. D. J. 1963. The effect of use on the vigor of browse plants. Job. Compl. Rep., Fed. Aid Project No. PRW78-R., Ariz. Game and Fish Dep. Processed. 8 p. + XII. PECHANEC, J. F., AND G. D. PICKFORD. 1937a. A weight estimate method for the determination of range or pasture production. J. Amer. Soc. Agron. 29:894-904. PECHANEC, J. F., AND G. D. PICKFORD. 1937b. A comparison of some methods used in determining percentage utilization of range grasses. J. Agr. Res. 54:753-756. SMITH, A. D. 1949. Effects of mule deer and livestock upon a foothill range in northern Utah. J. Wildl. Manage. 13:421-423. SMITH, A. D., AND D. M. GAUFIN. 1950. The use of movable paddocks in the study of forage preferences of mule deer and livestock. Tran. N. Am. Wildl. Conf. 15:512518. SMITH, A. D., AND D. D. DOELL. 1968. Guides to allocating forage between cattle and big game on big game winter range. Utah State Div. of Fish and Game Publ. 68-11. 32 p. SMITH, A. D., AND P. J. URNESS. 1962. Analysis of the twig length method of determining utilization of browse. Utah State Dept. of Fish and Game Publ. 62-9. 34 p. U.S. DEPT. COMMERCE. 1961-69. Climatological dataUtah Vols. 63-71.

DISTURBANCE INTENSITY AND ABOVE- AND BELOWGROUND HERBIVORY EFFECTS ON LONG-TERM (14 Y) RECOVERY OF A SEMIARID GRASSLAND

The importance of disturbance intensity and herbivory by cattle and white grubs, or the larvae of June beetles (including Phyllophaga fimbripes), to recovery of shortgrass steppe ecosystems in Colorado, U.S.A. were evaluated over a fourteen year time period. Disturbance intensity was defined by survival of the dominant grass species (Bouteloua gracilis) after an outbreak of root feeding activity by white grubs. Sixteen patches of vegetation consisting of four pairs of adjacent ungrazed-grazed by cattle locations with two replicates that were recently affected by white grubs were selected in 1977. Disturbance intensity was determined in 1977 by the area in each patch that contained live tillers of B. gracilis. Permanent plots were located both within and outside of each patch. Plant basal cover and density by species were estimated at time of peak aboveground biomass in six different years on each plot.Successional dynamics on patches was similar to areas affected by other types of disturbances, however, rate of recovery was faster for patches affected by grubs. Grazing by cattle was infrequently important to plant recovery, a result similar to effects of grazing on other aspects of shortgrass steppe ecosystems. Disturbance intensity was important to recovery of B. gracilis since tiller survival in 1977 was linearly related to cover in each year of sampling. For ungrazed patches, initial conditions were important to recovery of B. gracilis for as many as 14 years. For grazed patches, initial conditions decreased and grazing increased in importance through time. Changes in resource quality and a more uniform distribution of roots due to grazing likely resulted in more complete mortality of plants by grubs under grazed compared to ungrazed conditions.Persistence of shortgrass ecosystems in spite of disturbances with different intensities are determined at least in part by characteristics of disturbances interacting with the ability of plants to respond, and in part by the evolutionary history of the system. Although white grubs affect shortgrass communities infrequently, they have large and important effects on plant community structure through time, and represent an important class of disturbance defined by intensity.

Comparison of Techniques Used for Adjusting Biomass Estimates by Double Sampling

This paper compares the ratio and regression estimator procedures for adjusting ocularly estimated plant species biomass in different sizes and shapes of plots. The study was conducted in northeastern Colorado on shortgrass rangeland dominated by blue grama (Bouteloua gracilis). No significant differences were found in clipped plant biomass in 4 quadrat sizes between 0.18 and 0.50 m* and 2 shapes, circular and angtdar quadrats. For double sampling, the scatter plots of data strongly indicated a linear relationship through the origin for estimation and clipping. There were no significant differences between the adjusted mean weights by use of regression with and without intercept. The intercept was not significantly different from zero. Interpretation of correlation coefficient and variance of regression estimate with no intercept becomes difficult because the regression is forced through zero. Therefore, it is helpful to use regression with intercept. In the present study, estimates of both green and dry weights by ratio and regression estimation were comparable. Regression estimation is a minimum variance estimation comparable to ratio estimation even when the assumption of homoscedasticity is not true. The single factor of greatest importance to range management is an accurate appraisal of the volume of forage available. The task is difficult simply because forage varies in the weight of plant material produced by each species in a highly variable environment. Because all the forage cannot be harvested and weighed, we must obtain a reasonable estimate of the actual weight by sampling. Sampling is often not an easy task because data must be obtained within a span of 1 or 2 weeks so that growth differences are minimized. On summer ranges, the information on residual forage is obtained after the livestock have been removed and before snow makes the sampling impossible. If estimation of biomass for individual species is needed, then available funds and personnel may pose limiting constraints. In order to overcome some of these problems, a weight estimate method was designed by the personnel of the Intermountain Forest and Range Experiment Station during the summer of 1936 (Pechanec and Pickford 1937). The data are collected in two phases. In the first phase, the desired factor (xi) is measured by some indirect method such as ocular estimation. In the second phase, the desired factor is measured both directly and indirectly. The indirectly estimated values (xi) in the first phase are then adjusted by developing a mathematical relationship between the direct estimates (yi) and indirect estimates (xi). The sample size in the first phase is usually large compared with the sample size in the second phase. The sample in the second phase is usually &random subsample from the first phase but it may be drawn independently. The mathematical procedures used for adjusting the indirect estimates are linear regression and ratio estimation. The theory of Authors are with the Range Science Department, Colorado State University, Fort Collins, 80523 and the USDA-ARS Crops Research Laboratory, Colorado State University, Fort Collins 80523. This research was supported by U.S. AID Grant No. 391-80183 to Javed Ahmed and by facilities proved by USDA-ARS at the Central Plains Experimental Range, Nunn, Cola.. and Colorado State University Experiment Station Scientific Series No. 2620. Manuscript received June I, 1981. JOURNAL OF RANGE MANAGEMENT 36(2), March 1983 linear regression requires the assumption that the population regression of y on x is linear, that the residual variance of y about the regression line is constant (homoscedasticity), and that the population is infinite. No assumptions are made about the line passing through the origin. In the ratio estimation procedure, assumption of homoscedasticity need not be made but the estimator works well when up = xi. In many ways, the procedure is analogous to fitting a linear relationship between y and x which passes through the origin. When we are trying to decide what kind of estimate to use, a graph in which yi is plotted against xi is helpful. If the graph shows a straight line, relationship through the origin and variance of points yi about the line seem to increase proportionally to xi, then the ratio estimate is better than the least squares estimate for regression (Cochran 1963). During the summer of 1979, data were collected by double sampling from the Central Plains Experimental Range (CPER) near Nunn, Colo. CPER is administered by the Agricultural Resea Service, USDA. The objective of this study was to compare the ratio and regression estimator procedures for adjusting the ocularly estimated species biomass. The technique of double sampling and its statistical aspects are described in most sampling technique textbooks. The technique is also described by the National Research Council (1962) and by Schumacher and Chapman (1948). Pechanec and Pickford (1937) gave a detailed outline for the training of personnel for double sampling. Burton (1944) reported the ability of different personnel to estimate the yield in plots. Double sampling determination of herbage production in different vegetation types and the results were discussed by Pickford (1940), Wilm et al. (1944), Ragsdale (1956), Hillmon (1959), Hughes (1959), Shoop and Mcllvain (1963), and Tadmor et al. (1975). Double sampling was found desirable for extensive browse inventories by Carhart and Means (1941), Schawan and Swift (1941), Dasman (1948) and Blair (1959). Abstracts of the double sampling technique are given by Morris (1967). Statistical aspects of double sampling were reviewed by Francis et al. (1979). Optimum allocation of resources to direct and indirect methods of estimation is well defined by Cochran (1963) for a single factor under study and for a given sampling procedure. The optimum allocation formulations described by Schumacher and Chapman (1948) and Wilm et al. (1944) are. similar to those described by Cochran (1963). More recently, Ahmed (1980) and Ahmed and Bonham (1980) described a technique for optimum allocation in multivariate double sampling for biomass estimation.

The ecological niches of poisonous plants in range communities.

mountains of New Mexico. New Mexico Agr. Exp. Sta. Res. Rep. 166. Gray, J. R., and C. B. Baker. 1953. Cattle ranching in the northern Great Plains. Montana Agr. Exp. Sta. Circ. 204. James, L. F. 1978. Livestock poisoning by plants. U.S. Dep. Agr., Agr. Res. Serv. Unpublished mimeo. Kearl, W. G. 1967. Comparative livestock systems and technologies for Wyoming northern plains cattle ranching. Special report to the W-79 Technical Committee. Keeler, R. F., K. R. Van Kampen, and L. F. James (editors). 1978. The Effect of Poisonous Plants on Livestock. Academic Press, New York. Myles, G. A. 1962. Cost and returns on livestock ranches in north-western Nevada in 1961. Nevada Agr. Exp. Sta. Mimeo Circ. 166. Nielsen, D. B., and E. H. Cronin. 1977. Economics of tall larkspur control. J. Range Manage. 30:434-438. Norris, 3. J., and K. A. Valentine. 1957. Principal livestock-poisoning plants of New Mexico ranges. New Mexico Agr. Extension Serv. Circ. 274. Roberts, N. K., and C. K. Gee. 1963. Cattle ranches using public ranges year-long. Utah Agr. Exp. Sta. Bull. 440. Sperry, 0. E., J. W. Dollahite, G. 0. Hoffman, and B. J. Camp. (Undated). Texas plants poisonous to livestock. Texas Agr. Extension Serv., Texas Agr. Exp. Sta. Bull. 1028. Stoddart, L. A., and A. D. Smith. 1943. Range Management. McGrawHill Book Co., Inc., New York and London. 430 p. U.S. Department of Agriculture. 1973. Cattle raising in the United States. U.S. Dep. Agr., Econ. Res. Serv., Agr. Econ. Rep. 235. U.S. Department of Agriculture. 1975-76. Meat animals, production, disposition, income. Crop Reporting Board, Statistical Reporting Service. U.S. Department of Agriculture. 1977. Beef cattle numbers, January 1, 1977. Crop Reporting Board, Statistical Reporting Service. U.S. Department of Agriculture. 1977. Breeding sheep, I year and older, January 1, 1977. Crop Reporting Board, Statistical Reporting Service.

Alkaloid content of duncecap larkspur after two years of clipping.

Highlight : Duncecap ,larkspur plants clipped in vegetative growth stage (late June) for 2 consecutive years produced only leaves and no flower stalks the third year. These plants were significantly smaller and contained a significantly lower concentration of total alkaloids than those plants clipped later in the summer or than unclipped control plants, This susceptibility to injury by clipping may help interpret results of other control methods. Total alkaloid content of previously unclipped larkspur plants was highest in the early growth stages and declined throughout the summer. Total alkaloid content in late June ranged from 1.7% to 2.8% and was not correlated with amount or pattern of precipitation,

Long Term Effects of 2,4-D on Lanceleaf Rabbitbrush and Associated Species.

If properly applied, 2,4-D reduces rabbitbrush and forbs and allows grass to increase. This would be a desirable management tool on cattle ranges. The most effective kill of rabbitbrush was obtained with a treatment applied in June 1956 when soil was moist and when rabbitbrush was nearly in full leaf. When soil was dry and rabbitbrush was in bloom, spraying had no effect. Spraying before rabbitbrush was in full leaf reduced forbs but increased production of rabbitbrush.

Adaptation of Distance Measurements for Range Sampling

Modification of a distance measurement technique (the angle-order method) for estimating density, herbage production, and ground cover was tested in 1960 and 1961 at the U. S. Sheep Experiment Station in Idaho. Estimates of plant density and herbage production obtained by the angle-order method were compared with estimates on 9.6and 96-squarefoot plots, and estimates of cover were compared with estimates from line intercepts on 10-meter lines. Several limitations inherent in use of the angle-order method render it unsuitable for sampling complete plant communities of sagebrushgrass rangeland, but it may be used efficiently for estimating density, production, and ground cover for one or two key species.