The difference in the time at which the forage is sufficiently advanced to allow cropping on north and on south exposures at the same elevation in the oak-brush type may in extreme cases amount to two weeks. The difference is much less pronounced at the higher elevations than in the lower belts, except on very steep slopes where large snowdrifts occur. On the more gently sloping north and south exposures at the same elevation the forage is sometimes in practically the same stage of development when the range as a whole is ready for cropping. In order to study plant development on different slopes and exposures, a phenological table giving in a number the stage of development of the plant as a whole was developed, as follows: Beginning of growth (buds of foliage or blossoms swelling). 5 10 30 40 60 100 In accordance with these values representative species were observed on different slopes and exposures of the same elevation in all major forage types. The numerical values assigned to height or extent of leaf expansion were recorded only after actual measurements had been made; the extent of the swelling of the buds and the development of the flowers and fruit were determined ocularly. The method must be used with discretion as to individual species, but when a considerable number of species are observed, the results should give an approximate ultimate average. In general, when these numbers are used the average which indicates vegetative readiness will be from 20 to 30 per cent, according to the composition of the vegetation. The results of some observations in the oak-brush and in the spruce-fir types are given in Table 4, and their averages in Figure 8. The results show that there is considerable variation in the time interval of plant development on north and south exposures. The forage in the oak-brush type develops much earlier on south than on north exposures; but with increase in elevation this difference in development decreases until at elevations of 10,000 feet in the spruce-fir type the date of vegetational readiness for grazing is practically the same for the two exposures. It was also found that for each 1,000 feet increase in elevation the date of vegetational readiness is retarded approximately 18 days on south exposures and about 11 days on north exposures, or about 14 days on an average. This average delay varies, however, from 10 to 20 or more days in the intermountain region, according to local climatic conditions and the type and vigor of vegetation. CLOSING OF THE SEASONAL GRAZING PERIODS The time when livestock should be removed from the spring range to the summer range is determined chiefly by (1) the stage of growth and the abundance of forage on the summer range, (2) the grazing capacity of the early range as compared with that of the summer range, (3) the palatability of the forage on the spring range and the thriftiness of the animals grazed, (4) the water supply on both ranges, and (5) the need for and value of the forage on the early range for fall grazing. The stage of development of the forage in the aspen-fir belt is usually the determining factor as to when the livestock should be moved from the oak-brush belt in the spring. If the forage on the spring range is comparatively more abundant than that on the summer range, and the whole range is stocked on the basis of utilizing all of the forage, the animals should be held on the early range so long as there is sufficient palatable feed available there to keep them in thrifty condition without overgrazing. With limited summer range and abundant spring range, more animals will be maintained in good condition without injury to the forage crop in any type if they are held on the lower lands as late as possible. With a good balance in the grazing capacity of the spring and the summer range, on the other hand, the stock may be admitted to the summer range as soon as the forage there is ready FIG. 8.-Average phenological values for north and south exposures-1920 forage development in the oak-brush type occurs earlier on south exposures than those facing the north. Increase in elevation results in less variation of plant development between exposures for cropping. With limited spring range and abundant summer grazing grounds, which is often the case on national forests and is conspicuously so in those of the Wasatch Mountains, the situation becomes more complicated. Under such conditions it is necessary either to admit to the spring range at the beginning of the grazing season only a portion of the stock capable of being carried on the summer range, allowing the remainder to come on the range and pass immediately to the summer range when the summer forage is ready, or to delay the admission of all the animals until such a date that the summer range will be ready for grazing when they have properly utilized the forage on the spring areas. In some localities there are areas of spring range, limited in size, where scarcity of water is the controlling factor in the period of Early in the spring, owing to melting snow and occasional showers, there is an ample water supply; but with the approach of summer this dries up and it becomes necessary to move the stock to other areas. Because of the desirability or necesity of grazing the spring-range zone for a period in the fall, it is often essential to leave a certain amount of forage for this use at the close of the spring period. Occasionally the character of forage and the soil and climatic conditions are such that the feed necessary for the fall period is produced after the close of the early season, while the livestock are on the summer range. The closing of the grazing period on summer and fall ranges is governed largely by (1) proper utilization of the forage, (2) weather conditions and the trampling of wet soil, (3) the condition of the livestock, (4) the availability of late fall and winter forage elsewhere, and (5) the availability of water. Proper utilization may be defined as that degree of grazing which utilizes the largest quantity of forage possible without threatening the future productivity of the type, or which allows the type to recuperate if it is depleted. It is generally conceded that if from 10 to 25 per cent of the herbage of the more important palatable species remains in the fall proper utilization has been affected. When proper utilization has been attained, irrespective of the other factors mentioned, the livestock should be removed from the range. It is never good practice on any type to crop the forage in the fall so closely that the animals merely survive. Furthermore, such close cropping often results in the exposure of the crown and buds of the plant, a condition which is responsible for much winter-killing and loss of plants by frost upheaval. In some years weather conditions determine the proper time for the close of the grazing period on fall ranges. Frequently heavy snowfall early in the season makes it necessary to remove the livestock from the range earlier than would otherwise have been necessary. If the fall is exceptionally wet, they should be removed early to prevent damage to the range by trampling and loss in weight of the animals. It is especially undesirable to hold beef cattle overlong on the fall range, for at that season they usually lose in weight and finish. The availability of good feed elsewhere is not uncommonly a determining factor as to the time when the animals may be removed in the fall. Livestock should be removed from winter range early enough in the spring to allow time for the forage plants on this range to make a satisfactory new growth. The date of such removal is largely determined by the character of the vegetation and the prevailing moisture conditions. Where it is necessary to remove the livestock from the winter range before the spring range is ready, supplemental feed must be provided for the interval. GRAZING PERIODS IN EACH VEGETATIVE TYPE The following grazing periods are those which give the best results on each of the three major types of the Ephraim Canyon watershed, where the detailed studies were made: Oak-brush type (6,500 to 8,000 feet elevation): Spring to early summer, and late fall; May 20 to June 9, and October 1 to October 15. Aspen-fir type (7,500 to 9,500 feet elevation): Early summer to midsummer, and late fall; June 10 to July 9, and October 1 to October 15. Spruce-fir type (9,000 to 11,000 feet elevation): Summer to fall; July 10 to September 30. The first date shown for each type represents the average at which the range in that particular belt is ready for grazing. This may vary from year to year owing to exceptionally heavy or light snowfall and high or low temperatures. In actual practice, however, the aspen-fir type is used by some livestock throughout the whole period from June 10 to October 15 and parts of the oakbrush type may be used later in the season than June 9. RANGE MANAGEMENT BASED UPON PROPER SEASONAL USE MANAGEMENT PLANS Grazing that will meet the seasonal growth requirements of the forage can be obtained only by the application of a thoroughly sound and practical grazing-management plan. If cattle are simply turned loose on the range, even after the first zone is ready to graze, and no particular attempt is made to distribute them or to confine them to forage that is properly developed, they will rapidly drift to areas that are not yet ready for grazing and will become "located" as a natural habit on portions of the range most suitable to their peculiar desires. Once they are thus located it is usually impracticable to hold them to proper seasonal grazing or to keep them properly distributed during the remainder of the grazing season. On the other hand, experience has shown that it is entirely practicable by reasonable management to confine cattle to elevational zones during the proper seasons of their use. It is evident, then, that specific plans for proper distribution of livestock, together with the necessary means of controlling their movements, should be definitely provided for before they are admitted to any part of the range. As a beginning of the management plan a range must first be divided into the different seasonal zones. In doing this it will not always be possible to follow exactly the vegetative zones or types; the dividing lines must, so far as possible, be practical control lines and will often swerve into the next higher zone here and dip into the lower one there in order to follow ridges and fences or to permit gaps in topography or other barriers to be closed by short fences, since these features will aid in confining livestock, especially cattle, to the zone during the period when it should be grazed. Not only is it important to have livestock graze each altitudinal zone during a given period, but they must be distributed within the zone so as to obtain the fullest possible use of the forage on the entire unit without local overgrazing. Usually, then, the second step in the management plan divides the range into lateral or hori zontal distribution or management units, care being taken again to bound the units, so far as possible, with practical control lines. METHODS OF CONTROLLING STOCK Since sheep on mountain ranges are in herds under the care of herders, their control is a relatively simple matter. A band can be held in each natural management unit, during the period when the unit can best be used, long enough for proper utilization of the forage. The band can then be shifted in accordance with the management plan to another natural unit in the same seasonal zone and so be grazed through the units of each zone during the proper season. When the forage in the next seasonal zone has developed sufficiently to allow grazing there the band is moved into that zone and again held in each natural unit of the zone only long enough to utilize properly the forage of the unit. On cattle ranges it is essential to determine the carrying capacity of each of the natural management units and to plan the movement of the cattle so that each unit may be grazed during the proper period by the number of cattle representing its carrying capacity. The best basis for determining this carrying capacity and working out the whole management plan is grazing reconnaissance data. If this information is lacking, a careful examination must be made of the range in order to determine as closely as possible the location of the zonal and distribution units and the carrying capacity of these units. Once the number and distribution of the cattle have been worked out, it becomes essential to provide the mechanics for controlling and moving the animals. Control may be obtained by salting, herding, or fencing, or a combination of two or all of these. Salt forms a very essential part of the rations of livestock and because of the natural craving for it the distribution of salt on the range offers one of the most satisfactory-as well as one of the most economical-means of controlling cattle movements (1). Salt should be available where cattle first come on the range and should be distributed in accordance with the quantity and development of forage. No salt should be placed on or very close to areas such as upper zones not yet in vegetational readiness or overgrazed portions of the range, around watering places, on flats, in swales and other natural congregating places, or near poisonous-plant areas, recreational sites, and other places of intensive use. On the other hand, salt placed on slopes and ridges and in the more remote portions of the range has a great influence in drawing cattle to these places and obtaining proper utilization of forage which otherwise would not be grazed or at least would not be fully utilized. The number of cattle that should be grazed in a given unit and the length of time they should remain there is the basis for determining the amount and time of salting. With correct salting and stock distribution the forage and salt will be consumed by the time the next zone is ready and the animals will move practically of their own accord to the next higher zone where salt has recently been placed and where sufficiently developed forage is available. Salt should not be left on a unit of range after the forage has been fully utilized. Surplus salt on the upper elevations should be gathered and stored over the winter, since if left on the range it will tend to draw stock to those places too early and will largely defeat the effect of salt on the lower zones in keeping the animals there. Riding of course is essential to place cattle and salt properly on the range and to give necessary attention to the stock during the season. Also, some herding is ordinarily necessary to prevent cattle from going up drainage bottoms, along more or less level |