This description provides characteristics that may be relevant to fire ecology, and is not meant for identification. Keys for identification are available (e.g., [12,18,22,32]).
Desert peach is a clonal, deciduous, many branched shrub [18,32,50]. Aboveground stems are connected by an extensive network of rhizomes, and lignotubers occur at the base of most shrubs. Desert peach clones can be several acres in size [23,50]. Shrubs are typically 3 to 7 feet (2-3 m) tall, but heights of 10 feet (3 m) are possible. Desert peach branching is often wide and loose, and there are many short, stiff, spiny lateral branches [12,18,22,23,32]. Aboveground stems are short lived. From a large clone in the Medell Flats area of western Nevada, the maximum number of stem growth rings was 8 [49].
Leaves are simple, often bundled, and arranged alternately. Tips are pointed, and margins have minute teeth. Leaf blades measure 0.4 to 1 inch (1-3 cm) long, 3 to 7 mm wide [12,18,31], and can be summer deciduous [23]. Solitary flowers are most common, but clusters of up to 5 are reported [12]. Flower diameters measure 0.5 to 0.9 inches (1.2-2.2 cm) [22,23]. Desert peach produces mostly round drupes that measure a little over 0.4 inch (1 cm) and typically have dry and/or thin pulp [12,18,32]. Kay and others [23] report that fruit fleshiness depends on moisture availability. In years of above-average moisture, fruits are fleshy and split to expose the stone seed, but if moisture is average or below, fruits are described as "mummified" and the fruit flesh dries on the stone. Desert peach seeds are heart-shaped stones with a thick, hard coat that opens along a suture. Seeds are typically 1 cm long and wide [4].
Fire adaptations: Desert peach sprouts from rhizomes and/or lignotubers following fire [41,48,50], and is said to "reach its greatest development" on burned sites [22]. Postfire seedling establishment is rare [50] based on the limited postfire regeneration studies available.
FIRE REGIMES: The FIRE REGIMES in desert peach habitats in California and Nevada have been altered by European settlement. In some cases, species introduced during European settlement have increased fire frequency from what prevailed in presettlement times, and in other cases, exclusion of fire after European settlement has decreased fire frequency.
Cheatgrass in big sagebrush-antelope bitterbrush (Purshia tridentata) communities in the western Great Basin has fueled larger and more frequent fires since its establishment. Before cheatgrass invaded these habitats, the widely-spaced dominant shrubs and perennial bunchgrasses did not carry fire well. Cheatgrass has filled the vegetation interspaces and provided more continuous fuels. When winter and/or spring precipitation are adequate, cheatgrass grows 8 to 10 inches (20-30 cm) tall by May; plants dry by early June, and ignition and fire-spreading fuels are available from June to October [6].
From fire-scarred Colorado pinyon and Jeffrey pine (Pinus jeffreyi) trees in a small (<100 acre (40 ha)) area within the Walker River watershed of Nevada and eastern California, Gruell [16] determined that a low-severity fire burned somewhere in the area approximately every 8 years before European settlement. Sagebrush, antelope bitterbrush, rabbitbrush (Chrysothamnus spp.), and desert peach were the most common shrubs in the area. The Paiute occupied the Walker River watershed for over 10,000 years, and likely supplemented lightning ignition with anthropogenic ignition. Lightning storms are common ignition sources from May to September. However, between 1960 and 1997, the 266 wildfires that burned were controlled, and only 5 exceeded 100 acres (40 ha) in size. The largest was a 900-acre (400 ha) fire that burned in 1996. Elimination of the Native American ignition source and decreased availability of fine fuels through heavy domestic livestock grazing have contributed to an overall decrease in fire frequency and size and allowed for a dramatic increase in tree cover. In this Colorado pinyon woodland, woody fuel buildup has altered the low-intensity, frequent fire regime to a regime of high-intensity, infrequent fires occurring during extreme weather conditions [16].
The following table provides fire regime information on vegetation communities in which desert peach may be important. Find further fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find FIRE REGIMES".
Fire regime information on vegetation communities in which desert peach may occur. For each community, fire regime characteristics are taken from the LANDFIRE Rapid Assessment Vegetation Models [27]. These vegetation models were developed by local experts using available literature, local data, and/or expert opinion as documented in the .pdf file linked from each Potential Natural Vegetation Group listed below. Cells are blank where information is not available in the Rapid Assessment Vegetation Model. California Southwest Great Basin Northern Rockies California Vegetation Community (Potential Natural Vegetation Group) Fire severity* Fire regime characteristics Percent of fires Mean intervalInformation on the effects of fire on desert peach is lacking. Additional studies of fire in desert peach habitats are needed before recommendations regarding fire effects on this species are warranted.
Soils: Several sources describe and compare the characteristics of burned and unburned soils in desert peach habitats. Comparisons of the characteristics, nutrient content, extractable anions, and chemical composition of burned and unburned soils in big sagebrush-antelope bitterbrush/cheatgrass vegetation are provided by Blank and others [9,10,11].
Wildlife and fire management: Researchers found that a trade-off may exist between the use of prescribed fire to increase mule deer forage availability and the creation of capture and kill sites for mountain lions. On the eastside of the Sierra Nevada in eastern California, desert peach and cheatgrass dominated in the first years after a June wildfire. Before the fire, the community was dominated by bitterbrush and sagebrush. Desert peach/cheatgrass sites provided little cover, and mountain lions captured and killed prey in these sites more often than expected based on availability (P=0.002) [35,36].
Desert peach is often found on dry slopes, mesas, washes, ravines, draws, cliff bases, and rocky hillsides throughout its range [12,22,32].
Aspect: In singleleaf pinyon-Utah juniper woodlands of California and Nevada, desert peach was most common on eastern slopes [24].
Climate: Desert peach occupies sites with continental, semiarid to arid climates where the summers are typically dry [16,18,22]. Stark [44] reported in a revegetation manual that desert peach requires 6 to 8 inches (150-200 mm) of annual precipitation. In the Walker River Watershed of Nevada and eastern California, desert peach in Colorado pinyon-western juniper (Pinus edulis-Juniperus occidentalis) woodlands occupied sites with cold, dry winters and warm, dry summers. Based on a 22-year average at 6,500 feet (2,000 m), the annual precipitation was 9.5 inches (240 mm) [16]. In desert peach habitats in the Mill Creek Watershed of central Nevada, the climate is semiarid. Based on a 3-year period, annual precipitation ranged from 8.7 to 15.8 inches (220-400 mm), and over a 33-year period temperature extremes were -40 °F (-40 °C) and 108 °F (42 °C) [8].
Drought adaptations: Desert peach is morphologically and physiologically adapted to drought conditions. Specific leaf area (an indicator of the relationship between leaf transpiration area and water stored in tissues) is low, and the ratios of root length and weight to unit leaf area are high [39]. Summer dormancy and summer deciduousness are possible in dry years [23,44].
Elevation: The elevational range of desert peach is 3,000 to 8,900 feet (900-2,700 m). Narrower ranges are provided in the table below.
Desert peach elevation ranges by state or region State/region Elevation (m) California 900-2,600 [18] California (Glass Mountain Region, Mono County) 2,100-2,700 [19] California (southern) 1,070-1,980 [32] Nevada 1,500-2,100 [22] Intermountain West 1,200 to 2,400 [12]Soils: Desert peach is common on well-drained, poorly-developed, granitic soils [18,23,43]. Slightly saline or alkaline, coarse-textured soils are tolerated [44]. On Granite Mountain north of Reno, desert peach occurs in dense clumps on Mollic Haplargids with sandy to clay loam textures [41]. In central Nevada's Mill Creek watershed, desert peach occupies coarse to fine loamy Mollisols in big sagebrush/rubber rabbitbrush/cheatgrass vegetation and loamy, skeletal Haploxerolls in black cottonwood/big sagebrush communities [8].
Mule deer, mountain lions, and various small mammals feed on desert peach and/or utilize habitats where desert peach is important. While direct use of desert peach by livestock was not noted, abundance was typically lower on recently or heavily grazed than on past or lightly grazed sites. For more information, see Disturbance related succession.
Deer: Big sagebrush-desert bitterbrush-desert peach vegetation types on Morey Mountain and in the Hot Creek Valley of central Nevada are important mule deer habitat. Mule deer use averaged 179 deer-days/acre, but direct utilization of desert peach was not indicated [46]. In a review of mule deer diet studies, Kufeld and others [25] reported that mule deer use of desert peach was light (1-5% of diets) in the winter and fall and moderate (5-20% of diets) in the spring. Mule deer were said to "avidly" consume new desert peach growth in the early spring in northeastern and east-central California. The frequency of desert peach in mule deer diets was as high as 57.1% in the early spring [28].
Mountain lions: Desert peach and cheatgrass dominated sites in the first years after a June wildfire on the eastside of the Sierra Nevada in eastern California. Mountain lions captured and killed mule deer in these sites more often than expected based on availability (P=0.002). The desert peach/cheatgrass habitats were the most likely mountain lion capture and kill sites in the study area. However, researchers noted that they could only determine where mule deer were killed. They suggested that pursuits may have begun elsewhere, and that mountain lions may have pursued deer into the desert peach/cheatgrass vegetation where kills were perhaps more successful [35,36].
Small mammals: Numerous small mammals gather and consume desert peach fruits and seeds and/or browse desert peach stems. In the western Great Basin of Nevada, over 70% of desert peach fruits were taken from the canopy by white-tailed antelope squirrels. Great Basin pocket mice, deer mice, and Panamint kangaroo rats removed desert peach fruits and seeds primarily from the ground. They gathered insect-infested fruits and/or seeds at a decreased rate compared to uninfested fruits and seeds. In the same area, small mammals larder-hoarded 1,053 seeds and scatter-hoarded 901 seeds in 438 caches from 12 desert peach shrubs with scandium-46 labeled fruits. Caches had 1 to 20 seeds at 0.08- to 2.6-inch (2-67 mm) depths [3].
In years when black-tailed jackrabbit population densities were at a near maximum in northeastern California, 72% of desert peach shrubs had some girdling and 17% had all stems girdled. Seventy percent of desert peach shrubs were browsed. Thirty percent of shrubs were considered heavily browsed with 25% or more of the main stems browsed [29].
Palatability/nutritional value: Based on current year's leaf and stem tissue, researchers found that desert peach was 16.2% crude protein in April on a site in California [7].
Cover value: Desert peach likely provides cover for small animals present within its range; however, its importance as a cover species is not noted.
Sagebrush (Artemisia spp.) shrublands, yellow pine (Pinus spp.) forests,
and pinyon-juniper (Pinus-Juniperus spp.) woodlands are typical desert peach
habitat. Throughout its range, desert peach occurs in both late-seral and disturbed communities.
Desert peach occurs in big sagebrush/rubber rabbitbrush/cheatgrass (A. tridentata/
Chrysothamnus nauseosus/Bromus tectorum), singleleaf pinyon-Utah juniper (P.
monophylla-J. osteosperma), and black cottonwood (Populus balsamifera
subsp. trichocarpa)/big sagebrush communities that are considered late-seral vegetation
in the Mill Creek Watershed of central Nevada [8]. In the Glass Mountain Region
of Mono County, California, desert peach occurs in cheatgrass-dominated grasslands
considered to be recovering to a more native flora [19].
Desert peach is a dominant species in the following vegetation types in
Nevada:
Timing of desert peach flower development by state and/or region
State/region Typical flowering dates California (southern) March-April [32] Nevada April-July [22] Great Basin April-May [31] Intermountain West mid-April-early June [12]Desert peach regenerates asexually through rhizome and/or lignotuber sprouting [43,50] and sexually from seed production and germination [23]. Sprouting was the only method of desert peach regeneration on 1-, 2-, 3-, and 4-year-old burned big sagebrush/Thurber needlegrass (Achnatherum thurberianum) communities north of Reno, Nevada [50]. While asexual regeneration may predominate on disturbed sites, the relative importance of asexual and sexual regeneration has not received much attention in the available literature (2007).
Pollination: Insects are the primary desert peach flower pollinators; however, the wide flowers may attract other pollinators [31].
Breeding system: Desert peach produces perfect flowers [12,22,23].
Seed production: Late-season frosts reduce desert peach seed production. Flower and/or fruit damage is common when late-season freezing occurs, but flowering date is variable among clones growing in a common area and may ensure that some seed is produced each year. Flowering date can differ by as much as a month among neighboring clones [23].
Small mammals are seed predators and seed dispersers. Desert peach in the western Great Basin of Nevada produced between 0 and 5,200 fruits/shrub. Seed losses were low (6.5%), although 38% of fruits were insect infested. Over 70% of fruits were taken from the canopy by white-tailed antelope squirrels. Great Basin pocket mice, deer mice, and Panamint kangaroo rats removed desert peach fruits and seeds primarily from the ground, and fewer fruits and seeds with insects were removed than uninfested fruits and seeds [3].
Seed dispersal: Desert peach seed is dispersed by gravity and wildlife [3,42]. In the western Great Basin, dispersal by small mammals (white-tailed antelope squirrels, Great Basin pocket mice, deer mice, and/or Panamint kangaroo rats) was tracked by locating scandium-46 labeled fruits from 12 desert peach shrubs. The small mammals larder-hoarded 1,053 seeds and scatter-hoarded 901 seeds into 438 caches. Caches had 1 to 20 seeds at 0.08- to 2.6-inch (2-67 mm) depths [3].
Seed banking: Studies of the longevity of desert peach seed banks are lacking. Jorgensen and Stevens [20] suggest that dry desert peach seed stored at low temperatures and low humidity remains viable for 4 to 6 years, but Rowlands [40] reports very low germination rates of stored desert peach seed.
Germination: Desert peach seed germinates best after stratification. Some studies indicate that desert peach seed requires an after-ripening period of 1 to 3 months and 1 to 6 months of stratification [20]. Others studies have achieved moderate to high germination with stratification alone. When germination was encouraged at 68 to 86 °F (20-30 °C), percentages of 80% to 100% were reached after 30 days of stratification at 40 °F (2°C) in activated charcoal and after 15 days at 59 °F (15 °C) in sand [4]. Kay and others [23] found that cool moist stratification was best for desert peach germination. They also noted that seeds released from fleshy fruits germinated more readily than seeds with fruit flesh dried on them.
Desert peach germinates from unrecovered animal caches. In the western Great Basin in Nevada, 73 desert peach seedlings emerged from 29 caches. Emergence was similar under shrub canopies and in the open [3]. Seedling survival is described below in "Seedling establishment/growth". Successful emergence from caches may relate to seed burial, which ranged from 0.08- to 2.6-inch (2-67 mm) depths. Ferguson [15] noted that Rosaceae shrub seed germinates best when covered with soil. Uncovered seeds rarely germinated.
Seedling establishment/growth: While seedling emergence in the western Great Basin was similar from animal caches in the open and caches under shrub canopies, in dry years seedling survival was higher under shrub canopies than in the open. In wet years, seedling survival was not different between the 2 microsites. Overall seedling survival was low, and researchers suggested that episodic recruitment is likely [3].
Vegetative regeneration: The spread of desert peach through vegetative means is described by many [23,43,50]. Aboveground stems sprout from rhizomes and lignotubers to form thickets [43]. The death of older stems and emergence of new stems are continual [23]. From a large clone in the Medell Flats area of western Nevada, the maximum age of aboveground stems was estimated at 8 years [49]. Individual clones can be several acres in size [23].
Late-seral and early postdisturbance communities provide desert peach habitat. Desert peach grows best in full or almost full sun [18,44], but in semiarid to arid shrub-dominated habitats shade is not directly linked to seral condition. In the Mill Creek watershed, desert peach occurs in late-seral big sagebrush/rubber rabbitbrush/cheatgrass, black cottonwood/big sagebrush, and singleleaf pinyon-Utah juniper communities [8]. In other singleleaf pinyon woodlands in the Great Basin, desert peach is often present in early successional communities after fire or logging [30].
Disturbance related succession: While desert peach is often present in early postdisturbance communities, abundance may be lower on recently or heavily grazed sites compared to lightly or less recently grazed sites. On Medell Flats in western Nevada, desert peach was absent from heavily grazed sites, had a density of 800 stems/ha on moderately grazed sites, and had a density of 100 stems/ha on lightly grazed sites. Medell Flats were described as a "dust bed" in the early 1900s because of heavy domestic livestock use, but current cattle and sheep grazing intensity and patterns were not well described [49]. On Morey Mountain in central Nevada, desert peach cover and frequency were greater in deer and livestock exclosures than on unprotected sites. Duration and intensity of animal use were not given [46]. Density of desert peach was much greater on ungrazed than grazed sites after a fire in big sagebrush/Thurber needlegrass range north of Reno. The exclosure was constructed the same year as the July fire, and differences between grazed and ungrazed sites were evaluated 4 years later. Livestock grazing was heavy; in one year there was complete perennial grass utilization, and in another year, perennial grass utilization was heavy and utilization of cheatgrass was 80% to 90%. Desert peach density was 7/1,000 m² and 23/1,000 m² on grazed and ungrazed sites, respectively [13].
Revegetation manuals and studies indicate that desert peach is effective in revegetation or rehabilitation projects on disturbed sites within its range. In a review of species potential in revegetating disturbed Intermountain sites, desert peach establishment from transplants, soil stabilization characteristics, and disturbance adaptations were rated as "very good". Growth rate was considered "good", while establishment from seed and spread through asexual or sexual means were rated as "medium". Desert peach was recommended for use in desert shrublands, mountain brush, pinyon-juniper, and chaparral vegetation [37].
Desert peach survival was high in revegetation projects in California and Nevada. After 3 years, desert peach survival was 73% on slope cuts along a highway in Mono County, California. Forty desert peach seedlings were transplanted in mid-June. Transplants were watered at planting and 1 and 2 weeks after planting [43]. On north- and south-facing terraced road cuts on Granite Peak near Reno, 1-year-old desert peach seedling survival was over 80% in at least 2 of 3 planting years. Survival was evaluated 3 years after planting. Seedlings were grown from locally collected seed. Survival was typically lowest in 1977 when precipitation levels were about 65% of the previous year and when days above 90 °F (32 °C) were twice as frequent as in other planting years [14].