NATURAL AREAS AND REGIONS 



565 



B. Temperate semi-desert 



1. Vegetation (F. .). It is only on 

 relatively level plains or outwash slopes 

 that the sparse type of desert grassland 

 is found, carrying with it numerous 

 representatives of the true desert of 

 lower altitudes. The hills and moun- 

 tain slopes lying at the same altitude are 

 either desert or Xerophytic Forest. 

 In a few localities between 5000 and 

 6000 ft., on granitic outwash soil, there 

 are grasslands in which there occurs a 

 nearly continuous stand of Bouteloua 

 curtipendula, B. oligostachya, Festuca 

 arizonica, Sporobolus cryptandrus and 

 other grasses, with a very scanty rep- 

 resentation of such desert forms as 

 Opuntia spinosior, 0. whipplei, Feroc- 

 actus wislizeni, Acacia greggii, and 

 Momisia pallida. 



The principal part of the Desert 

 Grassland of Arizona consists of a very 

 open stand of the above, together with 

 numerous other species of Bouteloua, 

 Eragrostis, Sporobolus, Andropogon, 

 Hilaria, Festuca, Pappophorum and 

 Aristida, together with such conspicuous 

 plants as Yucca data, Nolina erumpens, 

 Prosopis, Acacia, Celtis and several 

 species of Opuntia. The Desert Grass- 

 land is much poorer in shrubs and small 

 trees than the Desert. Yucca elata is 

 usually present in this vegetation and 

 is its most striking plant, being 6 to 

 12 ft. in height and surmounted by 

 flower stalks from 3 to 4 ft. in length. 



2. Animals (C. T. V.}. With respect 

 to the animal life one can not draw much 

 distinction between Desert and Desert 

 Grassland regions without too many 

 specific distinctions for the limits of 

 this article. Of the most conspicuous 

 mammals mentioned for the Desert 

 it may be said that the antelope, mule 

 deer, antelope jackrabbit, banner-tailed 

 kangaroo rat, D. spectdbilis, and wildcat 

 tend to be more common in the higher 

 regions of the Desert Grassland. For 

 the birds the same may be said of the 

 scaled quail and the cardinal, while 

 the western kingbird supplants the 

 Cassin's. 



(7. Xerophytic forest 



1. Vegetation (F.S.). This vegetation 

 lies above the desert slopes of the larger 

 mountains and below the Evergreen 

 Forest, being confined to mountains in 

 southern Arizona, but found on plateaus 

 and plains in central and northern 

 Arizona. The dominant plants are 

 Juniperus pachyphloea, J. monosperma 

 or J. Utahensis, and Pinus edulis or 

 P. cembroides. With the junipers and 

 pinyons, especially in southern Arizona, 

 occur several species of evergreen oaks, 

 notably Quercus emoryi, Q. oblongifolia, 

 and Q. arizonica. In the open park- 

 like stand of these trees are found 

 numerous shrubs, as Arctostaphylos, 

 Garrya, Cercocarpus, Rhamus and 

 Fallugia, as well as several types of A gave 

 and Yucca, and a very large number of 

 root perennials and bunch grasses, the 

 whole forming an extremely diversi- 

 fied and very interesting type of 

 vegetation. 



2. Animals (C. T. V.}. Here we find 

 a greater change in the more conspicuous 

 faunal elements. In southern Arizona 

 the white tail deer is found, while from 

 the southern rim of the Mogollon plateau 

 northward the deer of this and the 

 montane forest are mule deer, doubtless 

 different forms from the desert mule 

 deer. The small, spotted and round- 

 tailed ground squirrels give way to the 

 larger, bushy tailed species of Citellus, 

 the so-called rock squirrels, while 

 Sciurus spp. now appear. The kit fox 

 gives way to the gray fox. Prairie dog 

 towns form a conspicuous feature of the 

 landscape where normally abundant. 

 The remarkable antelope jack drops out, 

 but the California jack remains, though 

 generally less plentiful than in the lower 

 zone. Peccaries, as now reduced in 

 numbers, are more plentiful here than 

 in the desert, though perhaps not origi- 

 nally so. The basarisk, Bassariscus, 

 the cougar, wolf and occasional jaguar 

 are among the more important new 

 elements in the mammalian fauna. Of 

 the smaller mammals mentioned for the 

 Desert, the changes here are chiefly in 



