Reviving Arizona's Rangelands

Semidesert rangeland before and after brush control.

Arizona’s Journal of Soil and Water Conservation rangelands

By Jerry R. Cox, Howard L. Morton, Jimmy T. LaBaume, and Kenneth G. Renard,

ISTORICAL records show that tions of land with precise areas. Early and 1880 (38). Furthermore, some 2,000

southeastern Arizona was a grass- American explorers, on the other hand, cows continuously grazed the Santa Cruz 38(4):342-345 land before 1880. Today, shrubby maintained journals describing vegetation Valley between Sahuarita and Tucson be- plants dominate the region. From 1880 to and location. Their records provide de- fore 1870, and about the same number also 1900, dramatic changes in the composition scriptions of grazing areas and vegetation grazed the Tanque Verde, Pantano, and of vegetation took place along major wa- in southeastern Arizona prior to 1870: Rillito grasslands during the same period. terways. Flooding and resulting channel- Santa Crux Basin. “We were off this San Pedro Basin. “The valley of thiswww.swcs.org ization, plowing of the floodplains, and morning [from Tucson]. . .and soon entered river is quite wide and is covered with a livestock grazing essentially eliminated the a thickly wooded valley of mesquite. A ride dense growth of mesquite, cottonwood and natural process of shallow groundwater re- of nine miles brought us to San Xavier de willow. The majority of the valley has charge. Changes in vegetation on upland Bac ...a mile further we stopped in a fine good grass.. .the bottoms having very tall range between 1930 and 1980 were grad- grove of large mesquite trees near the grass. There is excellent trout fishing but ual but just as destructive. We documented river, where there was plenty of grass. The the grass makes travel by wagon very diffi- the changes in the region’s vegetation be- bottom-lands resembled meadows being cult” (7). tween 1880 and 1980, determined why the covered with luxuriant grass and but few Sulphur Springs Basin. “This vast area changes occurred, and determined if the trees. The bottoms [between San Xavier is without either running streams or tim- range resource can be reclaimed. and Tubac] in places are several miles ber, but covered to a great extent with fine wide.. .and covered with tall, golden col- grass. Approaching Sulphur Springs from Early descriptions ored grass.. .divided by a meandering the East, the road lies for miles through a stream a dozen yards wide and as many dense growth of sacaton grass” (16). This Spanish explorers and ranchers were ac- inches deep, this shaded by cottonwoods, area was particularly adapted to grazing tive in southeastern Arizona (3, 12, 38), willows, and mesquites” (4). because of climate, abundance of alkali but it is difficult to correlate their descrip- The upland range [south and east of sacaton and salt grass in the playas, and Tucson] provided excellent summer and grama grass on the uplands (11). Jery R. Cox is a range scientist and Howard winter forage of grama grass, indian- Sun Simon Basin. “The valley of the San L. Morton is a supervisoy plant physiologist with the Agricultural Research Service, U.S. wheat, and winter annuals in 1900 (11). Simon is ...25 miles in width, and contains Department of Agriculture, 2000 East Allen Considering current vegetation and soil much fine grazing and some agricultural Road, Tucson, Arizona 85719. Jimmy T. La- conditions it may be difficult to visualize land. It is covered with grama grass. Mes- Baume is a consulting range scientist, now resid- the Santa Cruz Valley near Tucson cov- quite is most conspicuous and abundant ing in Alpine, Texas 79830. Kenneth G. Renard ered with grass. However, 100 cows con- from the base of the mountain [Graham]. b a research hydraulic engineer with ARS, . . USDA. 422 East Seventh Street, Tucson, tinuously grazed a big sacaton pasture of and sparse on the mesa.. .the sacaton and Arizona 85705. about 100 acres near Tucson between 1868 grama cover the plain.. . . The county

342 Journal of Soil and Water Conservation abounds in game, such as deer, antelope, wet and dry years. In fact, annual varia- wolf, wild turkey, duck and quail” (16). tions in precipitation were greater in southeastern Arizona than in any other The livestock industry part of the contiguous United States (13). The variability of individual storms and With the completion of southwestern total annual rainfall was illustrated at the railroads and dangers from Indian raids re- Walnut Gulch Experimental Watershed in duced, stockmen from Texas and investors 1967 (23,24).Annual rainfall was 10 inch- from England and the eastern United es at one location and 16 inches at another. States moved large herds of cattle and The distance between the locations was less sheep into southeastern Arizona in search than 10 miles. Thus, a wet year and a dry of “free grass” (11, 38). The winter of 1888 year occurred in the same general area. and summer of 1889 were wet and forage annual rainfall on upland range A sacaton stand near Tucson in 1902. was abundant. More cattle and sheep were would directly affect forage production. shipped from the Great Basin the following However, runoff from locations where winter. By 1891 there were an estimated rainfall was above average would accumu- 1.5 million cattle in Arizona’s southeastern late in lowlands every year and forage pro- counties (Table 1). duction would remain relatively stable. Summer and winter rains were well be- Before channelization in lowlands oc- low normal in 1891, and by June 1892 cat- curred, water entering major channels was tle began to die. The governor of the naturally spread over large areas by dense Arizona Territory estimated losses at 50 to stands of sacaton. As a result, water moved Copyright © 1983 Soil and Water Conservation Society. All rights reserved. 75 percent (11, 18). Another report noted, slowly in channels, shallow aquifers were Journal of Soil and Water Conservation “In my past trip [Vail, Arizona, to likely replenished each year, and discharge Nogales, Mexico] beef carcasses were so occurred over months rather than hours. numerous that they dotted the landscape.. . Between 1904 and 1914, summer rain- it is not possible to travel more than a fall was apparently above average (40), stones throw without seeing bones or de- forage was abundant, cattle prices were caying bodies of cattle” (28). high, shipping costs declined, and ranges A typical overgrazed hillside in south- Historians generally assume that live- were overstocked. A brief dry period oc- eastern Arizona in 1933. stock populations before 1900 were equally curred in 1917. There was severe drought distributed throughout southeastern in 1920. In the summer of 1933, southeast- Arizona. Livestock no doubt followed ern Arizona counties were classified as

minor drainages and grazed the uplands in emergency areas, and the Bureau of 38(4):342-345 wet years. But upland water development Animal Industry condemned and slaugh- and fencing began after 1930 (38), and tered range cattle (38). livestock grazing was likely limited to areas Passage of the National Industrial Re- near major drainages and playas in the covery Act and implementation of the 1890s. If this assumption is true, livestock Work Progress Administration and www.swcs.org use was limited to about 20 percent of the Civilian Conservation Corps in the 1930s land area (3.6 million acres), and livestock led to the opening of new grazing land. grazing was concentrated in sacaton bot- Federal and private groups developed toms and on nearby grama uplands. water on upland range, and fencing was Alkali sacaton (Sporobolus airoides) and used to divide land into grazing units (19). big sacaton (Sporobolus wrightii) were Range livestock populations that were pre- common before 1900. The plants covered viously confined to lowlands were then A retake of above scene in 1980, alluvial floodplains and nearby uplands in moved to upland range. showing increase of brush, cactus. southern Arizona and New Mexico (17). From 1890 to 1980, wet periods with Could these grasses, covering 20 percent of abundant forage were followed by over- the land, support 1.5 million cattle? stocking, and drought periods were fol- In a wet summer, when rainfall exceed- lowed by livestock reductions. With each ed 10 inches, both sacaton species pro- successive cycle, perennial grass productiv- duced up to 3 tons per acre of green forage. ity declined, and the rangeland supported But in a dry summer, when rainfall was fewer livestock. Excessive and continuous less than 5 inches, sacaton produced less use of perennial grass slowed plant re- than 1 ton per acre of green forage. In wet covery and favored invasion of woody years, or those before 1891, 20 percent of plants. Semidesert grassland became semi- the land area might have supported more desert shrubland (10, 11, 12, 18). than 1.5 million cattle. However, in dry If livestock populations have declined 88 years (1891 to 1893), the same area would percent over the past 90 years and if re- support 500,000 head or less. duced forage production caused channel- Annual precipitation varies greatly in ization, then one might logically assume southeastern Arizona, adding to the com- that cattle grazing caused the decline in Recent photo of a productive sacaton plexity of estimating forage production in forage production and is responsible for meadow with trees.

JUly-AuguSt 1983 343 channelization. Unfortunately, overgraz- mum cultivation (by county), about 2.6 in the 1970s and early 1980s, but mining ing continues to occur in southeastern Ari- million acres were cultivated in the five and urban uses are accelerating in Pima zona, but it is incorrect to infer that the southern counties; and if the areas farmed County (2). Agriculture, mining, industry, livestock industry is solely responsible. in 1980 are subtracted from the peak acre- and urban concerns are depleting ground- ages, then 2.2 million acres of farmland water at an alarming rate. Irrigated agriculture have been abandoned in the past 40 years. Arizona legislators have recently passed Urban growth and water use in urban legislation to limit groundwater removal. Farming in southeastern Arizona was areas will increase dramatically to the year We estimate that 283 million acre-feet of concentrated initially near major lowland 2030 (2). As urban demand for water in- water were pumped from shallow water drainage areas. Water was taken directly creases, water will be diverted from agri- tables in the past 80 years, while the from rivers. This practice was hazardous cultural uses, which have lesser value. This Arizona Water Commission (2) estimated on the San Pedro River because beaver means the abandonment of more of the re- that 265 million acre-feet of water were would build dams in irrigation ditches at gion’s farmland, a phenomenen occurring available in 1972 to a depth of 700 feet. In night and limit water flow to cropland. nationally at an average rate of 3 million 80 years, therefore, assuming minimal re- During the floods of 1895 and 1900, chan- acres per year (25). charge after 1895, residents of southeastern nel cutting resulted from the combination Arizona have removed morethan half of of farming, wagon trails, and grazing Effects of development all the stored water in shallow aquifers. rather than grazing alone. The soils Public concern for water conservation is associated with lowlands were extremely A majority of the population in south- genuine, but people continue to overgraze rich, and farming began after removal of eastern Arizona between 1890 and 1930 rangeland, build on floodplains, straighten the sacaton bunchgrasses (21). was rural and dispersed. Populations in channels to accelerate runoff, abandon Sacaton had slowed floodwater, trapped Cochise and Pima Counties were relatively farmland, fill swimming pools, and drive Copyright © 1983 Soil and Water Conservation Society. All rights reserved. Journal of Soil and Water Conservation sediment, and enhanced soil fertility on the even until 1940. From 1940 to 1980, the recreational vehicles in washes and on up- floodplains (39). Once removed, whether population increased gradually in all coun- land range. These activities continue to by burning, grazing, or plowing, there was ties except Pima. Today, more than 70 per- degrade land resources. nothing to slow water movement in the cent of the region’s people live in Pima lowlands. The result was channelization. County, most in and around Tucson. Is restoration possible? From 1930 to 1960, irrigated agriculture As population increased, so did demands expanded rapidly in the southeastern coun- for water and space. The fertile lowlands, Mechanical treatment (physical modifi- ties (Table 2). Decades of peak acreages previously sacaton bottoms and farmland, cation of the soil surface) of vegetation on were the 1940s in Cochise, 1950s in Pima were easy to develop, and housing quickly uplands was common until the oil short- and Pinal, and 1960s in Graham and Santa covered prime agricultural land. ages of 1970. Such treatment normally al- Cruz Counties. During periods of maxi- Agricultural water use declined rapidly ters soil structure, requires seeding to re-

store productivity, and often succeeds only 38(4):342-345 in years with above-average rainfall (8). Table 1. Cattle populations in southeastern Arizona counties between 1890 and 1980. Chemical treatment to control shrubs Range cattle Populationswere determined by using published estimates, or by subtracting began in the 1920s (27). New pelleted her- estimated dairy and feedlot cattle from estimated county populations. bicide formulations are less dependent on Counties Range Cattle time of application, have no liquid drift, www.swcs.org Year Cochise Graham Pima Pinal Santa Cruz Total Populations Reference and effectively control brushy plants (22). 1890 1,500 1,500 To estimate potential forage production 1900 172’ 85 98 42 43 440 438 1910 150 98 43 42 44 377 375 in the region, we selected a mixed brush 1920 84 47 64 45 27 267 263 site at an elevation of 3,100 feet. Annual 1930 91 42 88 21 30 272 268 1940 91 33 58 53 26 26 1 250 precipitation in the area is generally less 1950 65 51 41 38 27 222 210 than 12 inches, and reseeding at such loca- 1960 71 74 83 64 33 325 250 tions is not recommended (20). Brush spe- 1970 68 60 72 221 24 445 240 1980 67 35 40 207 16 365 188 cies were treated with a combination of 1,000 head. two pelleted herbicides, and we fenced the area to exclude livestock. Forage production on treated and ungrazed verses un- Table 2. Acres of irrigated agriculture in southeastern Arizona between 1900 and 1980 and treated and Ungrazed was 400 and 200 estimates of abandoned farmland in 1980 (abandoned farmland obtained by subtracting pounds per acre in 1979, 900 and 350 1980 estimates from peak production years). pounds per acre in 1980, and 1,500 and Counties ~~~ ~ ~~ 500 pounds per acre in 1981. Similar for- Santa Year Cochise Graham Pima Pinal Cruz Total Reference age responses on creosotebush sites at locations in southeastern Arizona, southern 1900 4,990 18,300 8,620 11,300 2,560 45,770 1910 4,900 38,820 10,160 25,430 4,770 84,080 New Mexico, and northern Mexico have 1920 12,980 32,400 16,880 28,650 2,610 93,520 been observed. 1930 377,010 136,410 280,550 75,740 4,990 874,700 One of the most difficult tasks associated 1940 907,700 2 10,130 293,660 593,930 168,610 2,174,030 1950 359,120 405,610 353,330 871,690 126,210 2,097,960 with water management is to control 1960 637,620 492,000 312,520 730,670 185,780 2,358,590 floodwater after it enters a channel. The 1970 90,920 51,850 50,030 260,110 2,100 455010 1980 88,630 45,900 47,280 221,610 3,970 407,390 dense stands of sacaton and beaver dams Acres of abandoned controlled water speed in primary chan- farmland 819,000 446,100 288,050 509,060 181,810 2,244,090 nels before 1890 (11). Restoration of

344 Journal of Soil and Water Conservation stream channels and riparian zones is pos- agencies and private organizations. Bull. T81121. Ariz. Agr. Exp. Sta., Tucson. in 'Outheastern Arizona 88 PP. sible when the rainfall is readily absorbed 21. Martin, S. C. 1963. Grow more grass! by by the upland portions of the watershed, have been and continue to be abused by mesauite control. Progressive Am. in Ariz. reducing overland flow (6). Runoff potential can be reduced on up-

lands after shrubby species are replaced its original state and be managedv--- properly cides for brush control in Southwestern with grass (15); however, clean water for ai user groups. However, a major United States and Northeast Brazil. In D. H. Hyder [ed.] Proc., First Int. Rangeland entering the channel will have a greater question remains: Are people socially, PO- Cong. SOC.of Range Management, Denver, erosive potential. Therefore, any efforts to litically, and institutionally mature CO~O.pp. 647-650. control water speed must be initiated enough to work together to make the net- 23. Osborn, H- B., and K. G. Renard. 1973. Management of ephemeral stream than- where channels begin. Water control sys- essary changes? !+, y. Irrigation'and Drainage 99: 207- tems usually consist of large dams designed Z14. REFERENCES CITED 24. Renard, K. G., andD. L. Brakensiek. 1976. to hold water. A more ideal situation is to 1. Arizona Crop and Livestock Reporting Ser- Precipitation on intermountain rangeland reduce water speed with vegetation and a vice. 1981. Arizona agricultural statistics, in the Western United States. In Proc., series of alternating, open-ended spreader historical summay of county data 1965- Fifth Workshop, U.S./Australia Rangeland 1980. Bull. S-16. Phoenix, Ariz. 140 pp. anel. Utah Water Res. Lab., Logan. pp. dams in riparian areas. As sediment is de- 2. Arizona Water Commission. 1975. -Phase 89-59. posited, the height of dams is increased. I-Arizona State Water Plan. Inoento y of 25. Sheets, K. R. 1981. 1s U.S. paving over too Resources and Uses. Phoenix, Ariz. 37 p. It may not be possible to seed big saca- much farmland? U.S. News and World 3. Bahre, C. J. 1977. Land-use histoy oFthe Rpt. 2: 47-48. ton directly into stream channels or ripari- research ranch, Elgin, Arizona. J. Ariz. 26. Sosebee, R. E. 1980. Water: a precious an zones because soils are high in silt and Acad. Sci. 12(2): 3-32. commodity to everyone. In Res. High- 4. Bartlett, J. R. 1854. [Personal narrative of lights-Noxious Brush and Weed Control; clay, but clumps from existing stands can explorations and incidents in Texas, New Range and Wildlife Management. Texas be removed, potted, and transplanted at Mexico, California, Sonora and Tech Univ., Lubbock. 2 pp. Copyright © 1983 Soil and Water Conservation Society. All rights reserved. field locations, or supplemental irrigation Chihuahua. Volumes I and 111. The Botani- 27. Streets, R. B., and E. B. Standle . 1938. Journal of Soil and Water Conservation cal Rev. 24: 193-252. Control of mesquite and noxious drubs on can be used. 5. Cable, D. R. 1977. Seasonal use of soil wa- Southern Arizona grassland ranges. Tech. ter by mature velvet mesquite. J. Range Bull. 74. Ariz. Agr. Exp. Sta., Tucson. 29 Manage. 30: 4-11. P Recommendations 6. Carlson, C. W. 1963. Drainage density and 28. TKbrnber, J. J. 1905. Range improvement. stream flow. Paper 422-C. U.S. Geol. Agr. Exp. Sta. Ann. Rpt. 16: 17-22. As a supplement to recent groundwater Surv., Washin on, D.C. pp. 36-42. 29. U.S. Bureau of the Census. 1902. Twelfth 7. Cooke, P. G. 1f38. [Journal of the March of census of the United States taken in 1900. legislation and plans for water importation the Morman Battalion, 184618471. The Bo- Population - part I, p. 64; agriculture - part into southeastern Arizona, we recommend tanical Rev. 24: 193-252. I, p. 418; agriculture - part 111, p. 825. that restoration of the semidesert grassland 8. Cox, J. R., H. L. Morton, T. N. Johnsen, Washington, D.C. Jr., G. L. Jordan, S. C. Martin, and L. C. 30. U.S. Bureau of the Census. 1913. Thir- also be considered. Historical documenta- Fierro. 1982. Vegetation restoration in the teenth Census of the United States taken in tion suggests that if watersheds were re- Chihuahuan and Sonoran Deserts of North 1910. Supplement for Ariz., pp. 32, 606- America. ARM-W-28. Agr. Res. Serv., 607, 621-622. Washington, D.C.

turned to grass the following conditions 38(4):342-345 Western Region, Oakland, Calif. 37 pp. 31. U.S. Bureau of the Census. 1922. Four- might occur: 9. Dixon, R. M., J. R. Simanton, and L. T. teenth Census of the United States taken in P Rainfall infiltration might increase, Lane. 1978. Simple time-power unctions 1920. Volume 111, pp. 78-79; volume VII, for rainwater infiltration and runoff. . 116-117; volume VI, part 3, pp. 134- thereby reducing the probability of down- Hydro. and Water Resources in Ariz. and !85. Washington, D.C. stream flooding (9, 17). the S.W. 8: 79-89. 32. U.S. Bureau of the Census. 1932. Fifteenth

10. Gardner, J. L. 1951. Vegetation of the creo- www.swcs.org F Water movement below 10 inches Census of the United States taken in 1930. sotebush area on the Rio Grande Val1 in Volume I, p. 92; volume 11, art 3, pp. 349- might eventually recharge subsurface New Mexico. Ecol. Monograph 21: y79- 350; irri ation of agricultur3 lands, pp. 74- aquifers (5, 26). 403. 75. Wasiington, D.C. 11. Griffith, D. 1901. Range improoement in D Perennial forage production might 33. U.S. Bureau of the Census. 1942. Sixteenth Arizona. Bull. 4. Bur. Plant Industry, Census of the United States taken in 1940. increase (21). Washington, D.C. 12 pp. Volume 11, part 1, p. 370; volume 1, part 6, D Ephemeral streams might become 12. Hastings, J, R., and R. M. Turner. 1965. pp. 404-405; irrigation of a iculture lands, The changing mile. Univ. Ariz. Press, Tuc- pp. 111-113. Washington, B.C perennial streams (14,26). son. 34. U.S. Bureau of the Census. 1952. Census of b The resulting environmental diver- 13. Hershfield, D. M. 1962. A note on the vari- population and a riculture taken in 1950. sity might enhance wildlife habitat as well ability of annual recipitation. J. Applied Volume 11, part !, pp. 40-42; volume 11, Meterol. 6: 575-5i6. part 30, pp. 215-216; volume 111, pp. 1-11. as recreational and aesthetic values (26). 14. Hibbert, A. R. 1969. Water yield changes Washington, D.C. The question of whether these condi- after converting a forested catchment to 35. U.S. Bureau of the Census. 1960. Census of grass. Water Resources Res. 5: 634-640. tions would follow cannot be answered be- population and agriculture taken in 1959. 15. Hibbert, A. R., E. A. Davis, and T. C. Arizona counties. Washington, D.C. cause existing watershed data were collect- Brown. 1975. Managing chaparral for wa- 36. U.S. Bureau of the Census. 1972. Census of ed on degraded rangelands and do not rep- ter and other resources in Arizona. In Proc., population and agriculture taken in 1969- Watershed Manage. Symp. Am. SOC.Civil 1970. Volume I, part 4, pp. 4-14; volume I, resent grassland conditions. An entire wa- Eng., New York, N.Y. pp. 445-469. part 43, pp. 268-270. Washin on, D.C. tershed is needed where large-scale manip- 16. Hinton, R. J. 1878. [The handbook to Ari- 37. U.S. Bureau of the Census. 19%. Census o ulation of vegetation can take place. The zona]. The Botanical Rev. 24: 193-252. population and housing taken in 1980. pf 17. Hubbell, D. S., and J. L. Gardner. 1950. Preliminary Report. Washington, D.C. effects of these vegetation changes must be Effects of divertin sediment-laden runoff 38. Wagner, J. J. 1952. Histoy of the cattle in- monitored to determine (a) herbicide resi- to range and cropTand. Tech. Bull. 1012. dust in Southern Arizona, 1540-1940. U.S. Dept. Agr., Washington, D.C. 83 pp. dues, (b) forage and livestock production, Soci#Sci. Bull. 20. Univ. Ariz. Press, Tuc- 18. Humphrey, R. R. 1958. The desert grass- son. 132 pp. (c) erosion, (d) runoff, (e) infiltration, (f) land. The Botanical Rev. 24: 193-252. 39. Wooten, E. O., and P. S. Standley. 1911. wildlife populations, and (g) possible 19. Johnsen, T. N., Jr., and J. W. Elson. 1979. The grasses and grasslike plants of New Sixty years of change on a Central Arizona groundwater recharge over time. Plan- Mexico. Bull. 81. New Mex. Agr. Exp. Sta., grassland -juniper woodland ecotone. Las Cruces. 174 pp. ning, implementation, and review of this ARM-W-7. Sci. and Educ. Admin., Agr. 40. Wooten, E. 0. 1916. Carrying capacity of watershed research should be accom- Res.,Oakland, Calif. 28 pp. grazing ranges in Southeastern Arizona. 20. Jordan, G. L. 1981. Range reseedin and Bull. 367. Bur. Plant Industry, U.S. Dept. plished by city, county, state, and federal brush management in Arizona rangeknds. Agr., Washington, D.C. 40 pp. 0