James N. Davis

Fire Rehabilitation Using Native and Introduced Species: A Landscape Trial

Abstract Following the 1999 Railroad Fire in Tintic Valley, Utah, we initiated a large-scale fire rehabilitation study comparing a predominately introduced species seed mix used by the US Department of Interior–Bureau of Land Management (BLM), a mix of native and introduced species provided by the US Department of Agriculture–Agricultural Research Service (ARS), and 2 native seed mixes (high and low diversity). Mixes were seeded with a rangeland drill on the big sagebrush (Artemisia tridentata var. wyomingensis [Beetle & A. Young] Welsh) study area whereas the pinyon–juniper (Pinus edulis Engelm.–Juniperus osteosperma [Torr.] Little) woodland study area was aerially seeded followed by 1-way chaining. On drill-seeded plots and by the third year after seeding the native high-diversity mix (16.4 kg pure live seed [PLS]·ha−1) had the highest seeded species cover (11.5%) and density (14 plants·m−2). Both the BLM (9.3 kg PLS·ha−1) and ARS (9.1 kg PLS·ha−1) seed mixes had higher seeded species cover (BLM = 8.5%, ARS = 8.2%) and density (BLM = 8.4 and ARS = 7.2 plants·m−2) than plots seeded to the low-diversity native mix (8 kg PLS·ha−1, cover = 3.8%, density = 3.6 plants·m−2). Indian ricegrass (Achnatherum hymenoides [Roemer and J. A. Schultes] Barkworth ‘Nezpar’) in the native high-diversity mix was especially successful on the sandy soils of the drill site, whereas seeds of other species may have been buried too deep for optimum emergence. Aerially-seeded and chained plots had similar and successful seeded species frequency, cover, and density (third-year average = 10.6% cover, 17.2 plants·m−2) among all species mixes. All seeded plots had lower cover of annual species than unseeded plots, indicating that revegetation is necessary to reduce weed invasion following catastrophic wildfire in big sagebrush communities lacking residual perennial understory vegetation.

Mule Deer Preference and Monoterpenoids (Essential Oils)

Wild wintering mule deer browsed on a uniform shrub garden near Helper, Utah.1 On this grrden, 21 accessions from SArtemisia taxa were selected to test the relationship between deer preference for these accessions and the amount of monoterpenoids present in the accessions. Deer preferences were determined by measuring removal of current year’s growth. Samples of current year’s growth (leaves and stems with terminal buds) were collected at the time preference measurements were taken to determine monoterpenoid content. Deer use ranged from zero to 83% of the current year’s growth. Total monoterpenoid content among accessions varied from 0.75 to 3.62% of dry matter. Coefficients of determination, preference versus monoterpenoid levels (total and individual) ranged from 0 to 18%. The monoterpenoid content of various accessions of Artemisia taxa was not significantly related to deer preference. Because of the bacteriostatic and bactericidal properties of monoterpenoids (essential oils), a number of workers became concerned about possible adverse effects monoterpenoid-producing plants might have on ruminant digestion through suppressing rumen microorganisms. Nagy et al. (1964), Oh et al. (1967), Nagy and Tengerdy (1968), and Schwartz et al. (198Oa) have reported in vitro evidence that monoterpenoids, when in high enough concentrations, do suppress activities of rumen microorganisms. From these reports the following hypotheses have emerged: (I) when big sagebrush exceeds 15-30% of the diet, ruminant digestion will be adversely affected2 (Wallmo and Regelin 198 1); (2) the “theoretical”decline of mule deer in the western United States may be due to high (over IS-30%) big sagebrush consumption (Dietz and Nagy 1976); and (3) mule deer selected monoterpenoid-containing forage plants with the least amount of monoterpenoids (Nagy and Tengerdy 1968, Schwartz et al. 1980b, Wallmo and Regelin 1981). The third hypothesis, monoterpenoid content versus preference, is the subject of this study. During digestibility trials, Smith (1950) noted that penned deer showed definite aversion to individual big sagebrush plants. Mule deer preference for certain accessions and/ or individual plants of big sagebrush has been observed in the field by a number of researchers (McArthur et al. 1979, Sheehy and Winward 1981, Welch et al. 1981). Welch et al. (1981) demonstrated differential preference of wintering mule deer for accessions of big sagebrush grown on a uniform garden. A few attempts have been made to relate monoterpenoid content to preference (Sheehy 1975, Scholl et al. 1977, Radwan and Crouch 1978, Schwartz et al. Welch and h&Arthur are principal research plant physiologist and principal research plant geneticist, respectively, with the USDA, Forest Service, Intermountain Forest and Range Ex riment Station, Shrub Sciences Laboratory, Provo. Utah 84601; Davis is wildh e research biologist with the Utah Division of Wildlife Re,F sources, Shrub Sciences Laboratory, Provo (W-82-R. Job I). Manuscript received April 7, 1982. ‘The shrub gardenat the Gordon Creek Wildlife Management area near Helper, Utah, is cooperatively maintained by the Utah State Division of Wildlife Resources (W-82R, Job I) and the Intermountain Forest and Range Experiment Station. *A number of studies have been reported that challenge the idea that big sagebrush monoterpknoids (essential oils) suppress microbial digestion (Smith 1950. 1952.1957, Sheehy 1975, Welch and McArthur 1979. Tueller 1979, Connolly et al. 1980, Kufeld et al. 1981, Narjisse 1981, Welch and Pederson 1981. Cluff et al. 1982. Pederson and Welch 1982. White et al. 1982a). 1980b, Narjisse 198 I, White et al. 1982b). Results of these studies fall into two categories: (1) monoterpenoids adversely influence preference (Schwartz et al. 1980b, Narjisse 1981-goats), and (2) monoterpenoids have little influence on preference (Scholl et al. 1977, Radwan and Crouch 1978, Narjisse 1981-sheep, White et al. 1982b). With this conflict in mind, we undertook this study to determine wintering mule deer preference for accessions of Artemisiu taxa grown on a uniform garden as related to monoterpenoid

Pinyon-juniper chaining and seeding for big game in central Utah.

Vegetation and soils were evaluated on 5 different-aged, mechanically treated and seeded pinyon-juniper sites and compared to adjacent untreated areas. Plant cover was significantly changed after treatment: trees were reduced from 26 to 6% total ground cover; shrubs were increased from 2 to 8% ground cover; and herbaceous plants increased from 2 to 13% ground cover. Annuals and perennial forbs were 75% of the total plant cover on the 2-year-old site, perennial grasses and shrubs dominated the plant cover (52 to 83%) on three, 14- to 20-year-old sites, while shrubs and trees combined for 94% of the plant cover on the 24-year-old site. Two Agropyron grass species showed good establishment and persistence after seeding. Seeded forbs contributed about 5% of the total plant cover on the 2-year-old treated site and they declined on older treated sites. Seeding of shrubs was only successful on sites where the shrub species was already present in the understory naturally. Seeding of nonnative shrub seed did not produce stands. Even though tree cover was reduced after treatment, total tree density was not. Shrub density increased from an average of 800 plants/ha on untreated areas to 2,750 plants/ha on treated areas. Juniper mortality during mechanical treatment varied from 60 to 91% and was related to the percentage of trees estimated to be 60+ years old (r = 0.97) and with the number of trees greater than 5 cm in stem diameter (r = 0.71) on the adjacent untreated sites. Big game pellet group counts were not different between untreated and treated sites, suggesting that big game make use of these treated areas because of increased forage and browse and in spite of reduced security cover.

Adaptation of forage Kochia accessions across an environmental gradient in rush valley, Utah

Forage kochia (Kochia prostrata) is native to Eurasia. It is a useful plant for reclamation in semiarid and arid regions with mineral soils. Fourteen accessions representing both forage kochia subspecies and all known polyploid levels (2x‐6x) were tested for adaptation over an environmental gradient represented by three study sites differing in native plant composition, average annual precipitation, and soil type. Plants were established by transplanting in 1988 and 1989 and evaluated for growth (height, crown diameter, biomass) parameters and for stand establishment, growth habit, uniformity of growth, vigor, cover, seed production, survival, and recruitment from 1990 to 1992. Soil characteristics (pH, SAR, salinity, sand, clay, silt, organic matter, NO3‐N, Ca, Na, Mg, P, K, CaCO3, and effective rooting depth) were measured at each study site. Two hypotheses were addressed. First, it was confirmed that forage kochia accessions in general perform better in lighter textured soils and at higher precipitatio...

Runoff and sediment response to tree control and seeding on a high soil erosion potential site in Utah: evidence for reversal of an abiotic threshold: Runoff and sediment after tree control

Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah 84602, USA Utah Division of Wildlife Resources, Springville, Utah 84663, USA Wallowa–Whitman National Forest, Baker City, Oregon 97814, USA Utah Division of Wildlife Resources, Orem, Utah 84058, USA Utah Division of Wildlife Resources, Ephraim, Utah 84626, USA Correspondence Bruce A. Roundy, Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT 84602, USA. Email: bruce_roundy@byu.edu