312 GRAZING INDICATORS. 



more accurate measurements are necessary, especially in connection with the 

 varying carrying capacity of wet and dry periods. Changes in composition 

 and variations in production year by year can be determined only by the 

 use of permanent quadrats. Some of these are charted, while others are 

 clipped and the herbage weighed. The most significant measurement, how- 

 ever, is that furnished by weighing the individual animals from month to 

 month, or at the beginning and end of the season. 



Essential factors. Range improvement may be effected in some degree by 

 any one of a large number of processes. Thoroughgoing improvement, how- 

 ever, must take them all into account, in so far as they are concerned in a 

 particular range. It is obvious that some of these, such as proper stocking 

 and rotation grazing, are of universal importance, while others, such as the 

 eradication of prairie-dogs or poisonous plants, apply only to certain ranges. 

 The essential features of the complete system of range improvement proposed 

 here are: (1) proper stocking; (2) rotation or deferred grazing; (3) eradication 

 of rodents, poisonous plants, weeds, etc.; (4) manipulation of the range by 

 clearing, burning, etc.; (5) improving the cover by sowing and planting; (6) 

 forage development; (7) water development; (8) herd management. Con- 

 tributing factors are found in classification and range surveys, the economic 

 aspects of ranch management, and an adequate land system. Practically all 

 of these have been regarded as more or less essential to range improvement 

 since the first proposals of Smith, 25 years ago, and the present treatment as- 

 sumes only to correlate them more closely and to work some of them out in 

 greater detail. The distinctive features of the system are the use of climatic 

 cycles and succession as universal bases, the employment of indicator plants, 

 the use of inclosures and exclosures together with permanent quadrats as 

 measures, and the development of new methods of manipulating and modify- 

 ing the range, especially in the production of mixed grazing types. 



Proper stocking. ^The primary object of range improvement is to secure 

 and maintain the maximum carrying capacity. The chief factors in this are 

 proper stocking and rotation grazing. The optimum degree of stocking, how- 

 ever, can be determined only by actual trial accompanied by measurement of 

 the results. Such trials can be made by the ranchman himself wherever he 

 has control of his range, but until their necessity becomes generally recognized 

 they must be made for the different grazing types by the experiment stations 

 and similar agencies. The investigation of carrying capacity by actual 

 grazing test can be made by either the extensive or intensive method. The 

 first is more practical on ranges as they exist; the latter is more accurate and 

 demands a greater equipment. The results of an extensive study of carry- 

 ing capacity on the Jornada Reserve have been brought together by Jardine 

 and Hurtt (1917: 12). Eight different grazing types occur on the reserve 

 and the carrj'ing capacity varies greatly for the different communities. Per- 

 manent quadrats were employed to determine variations in yield from year 

 to year, as well as the rate of increase under rotation or protection. Since 

 both rotation and reserve grazing were necessarily practiced, no definite 

 studies were made of the basic carrying capacity under full grazing for the 

 entire season. Such studies are possible only under the intensive method 

 and in an essentially uniform type. Their great value lies in making it pos- 



