Griffiths (1904) was essentially the first investigator with the Bureau of Plant Industry to initiate range investigations on SRER. Between 1900 and 1903, he made observations on (1) forage production, (2) plant phenology, (3) plant inventories, (4) carrying capacity, (5) erosion, (6) livestock behavior, and (7) range conditions. The Bureau's research objectives were to determine the period of time that would be necessary for the range to regain its productivity, and to determine the grazing capacity of such a range once it had reached a satisfactory condition. The Bureau's research objectives were to is during 1900-1915 was on basic studies of growth habits of important forage plants and grasses for the purpose of determining the best methods of assessment, care, and improvment of grazing lands. Special emphasis was placed on basic studies of growth habits of important forage plants and grasses for the purpose of determining the best methods of assessment, care, and improvment of grazing lands. At the time of the establishment of the SRER in 1903, forage conditions were deteriorated as a result of unregulated heavy yearlong grazing the previous years. It was immediately fenced and domestic livestock were excluded until 1915. In 1915, responsibility for range research outside the National Forests was transfered to the Forest Service. This resulted in additional intensive studies of the relation of climate to range-plant growth and use, and studies of methods of range management on semidesert ranges. Range research ceased during World War I but quickly resumed after the war. The passage of the McSweeney-McNary Forest Research Act of 1928 marked a new epoch in range research. All Forest Service range research was consolidated under regional forest and range experiment stations, with integration and coordination of range research on a national basis with other research agencies.
Emphasis of range research on SRER changed over time. SRER was not grazed between 1903-1915; hence, early investigations prior to 1915 dealt primarily with assessment of range conditions and determination of possible strategies for betterment of rangeland resources. Grazing on SRER was initiated in 1915 and continued to 1957 on a yearlong basis. Between 1915 and 1940, investigations focused on range economics, betterment of livestock breeds and calf crops, and livestock management strategies, but were driven by 2 major objectives. First of these was determination of better methods for managing semidesert range lands, typical of Santa Rita, for the purpose of improving and maintaining them on a sustainable basis of productivity. The second objective focused on handling cattle on the range so as to obtain greatest annual returns. Some important wildlife works dealt with the impacts of rodents on the range resources and determination of foods of mule and white-tailed deer. Other studies started during this period were carried on until the 1960's and 1970's, e.g., noxious plant control, determination of grazing capacity, season of use, and proper use levels of semidesert grasses. Grazing systems research began as early as 1937 with tests of yearlong grazing versus summer deferment.
A program of evaluating range reseeding trials began in 1935 and ended in the mid-1950's. During the 1940's, as a result of the Hope-Flannagan Research and Marketing Act, funds became available for basic research on the physiology and ecology of noxious range plants. Several studies were started: relationships (reproduction, production, and survival) of important semidesert plants; cattle grazing habits; resistance of forage grasses to grazing; and vegetational changes over time. Great attention was paid to undesirable species such as burroweed, cholla cacti, mesquite, and prickly pear, and methods of control.
The 1950's and 1960's, coincident with the consolidation of the Southwestern Station with the Rocky Mountain Station in 1953, were a time of basic research on semidesert grasses. Various studies dealing with plant competition relationships, plant- drought interactions, and physiological response of mesquite to herbicides were initiated. Major emphasis was placed on control of mesquite, burroweed, and other undesirable species. These same efforts led to the study of the effects of fire (mortality, production, resistance) on various grasses and shrubs. Coincident with these studies, the ecology and life history of grass and noxious plants were also studied. Some basic studies dealing with deer-livestock interactions were initiated. The successful establishment of lehmann lovegrass in 1954 led to various works dealing with the use and management of the species up until the closure of the Southwestern Experiment Station in 1975.
Since 1975, research on semidesert grasslands has been de- emphasized in light of other current problems, such as wildlife- livestock interactions, production and utilization of Lehmann's lovegrass, cattle foraging behavior, and small mammal habitat interactions. Extensive research has been conducted on rodents on their habitats, insects, e.g. termites, quail, javelina, coyotes, and deer. The establishment of Lehmann's lovegrass as a monoculture presented new challenges to develop strategies for its proper utilization. However, the extensive amount of work performed on SRER led to the present state of knowledge or range management principles on semidesert grasslands, especially with regard to grazing systems, seasons of use, production-utilization levels, and general range ecology. Resource managers draw upon this data base to design management plans and grazing strategies suitable for southwestern rangelands.