12 A PROTECTED STOCK RANGE IN ARIZONA. 



between a good crop and a small one in the perennial-grass region of 

 these deserts is not so much due to a larger number of plants as to 

 larger plants or clumps of plants. 



Our experience upon this inclosed tract seems to indicate that the 

 natural restocking of the perennial range by new plants takes place 

 at irregular intervals. The ratio of increase may bear no relation to 

 the quantity of seed produced the previous year. In other words, 

 a favorable season for seed germination following a poor season of 

 seed production may develop vastly more seedlings than one of poor 

 distribution of moisture following an abundant seed production. 

 Since this area was fenced, there has been but one season when the 

 production of perennial-grass seedlings failed almost entirely. On 

 the other hand, there have been but two years in five when a decided 

 increase was noticed, the increase in 1907-8 being enormously greater 

 than any of the others. 



ARTIFICIAL RE SEEDING. 



Many attempts have been made to introduce forage plants in this 

 section, both in the large inclosure and upon the holdings of private 

 individuals in the vicinity. There is but one species that has given 

 any beneficial results. Alfilerilla (Eurodium cicutarium) has been 

 tried several times and in various situations. In brushy pastures in 

 the upper foothills it has produced a thick mat of herbage some years, 

 while in others the growth has been poor. All in all it has done well 

 in patches, but only in the most favorable situations, in rather loose 

 soil, where the grazing has been quite heavy and there is open 

 mesquite brush. This plant grows in the winter; consequently, 

 the shade furnished by the mesquite is at a minimum when the 

 plant grows. It has taken four or five years for it to become well 

 established. 



In the open foothills, where the best pasture is found, the growth 

 of this plant has been of no consequence. It has been started in 

 several places, and indeed there were patches of it to be found in 

 several situations when the field was inclosed, but even these have 

 not spread. In short, the plant does not appear to be able in this 

 situation to compete with native vegetation when the latter is not 

 grazed. In one locality, along the fence line, there has been for 

 years a patch of a few acres established no one knows how, but prob- 

 ably by sheep. This has been watched with interest, but the growth of 

 alfilerilla has been less under protection than in the open where the 

 land was heavily grazed. 



In all, some two hundred species of forage plants have been planted 

 in this inclosure. Many native species were tried, but the vast 

 majority used were of foreign importation. At one time the Office 

 of Forage-Plant Investigations of the Bureau of Plant Industry fur- 



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