Stratified seed must be sown while wet. A five-hour soak in a three percent hydrogen peroxide solution is an effective short-term treatment to improve germination 2. Seed life and recommended storage conditions. Field dried seed can be stored in bags in a cool, dry place for up to five years 2. Propagation recommendations. Seed should be sown in the spring or fall. It should not be sown more than two centimeters deep 2.
Soil or medium requirements. The propagation medium should be well drained. Installation form form, potential for successful outcomes, cost.
Direct seeding of antelope bitterbrush has shown mixed results. Research has shown that direct seeding is fairly successful in pinyon-juniper communities, but less so in big sagebrush and mountain brush types. Establishing antelope bitterbrush from small seedlings requires good seedbed preparation, including weed control.
Seedling survival can be very low, especially when the seedlings must compete with cheatgrass Bromus tectorum. Installation of larger, containerize individuals has shown more success in some studies 1. Recommended planting density. Shrubs should be installed feet on center depending on the desired density and expected mortality 3. Care requirements after installed. Information on care requirements was not available.
Supplemental water would, of course, increase survival of any plant in an arid environment. Normal rate of growth or spread; lifespan. Adult plants reach 0. Presence In Idaho. Global Rank G3G5 What do these ranks mean? Classifications Plant. Learn more Encyclopedia of Life eol. Taxonomy Plant in the Purshia Genus.
Kingdom: Plantae. Phylum: Anthophyta. Class: Dicotyledoneae. Order: Rosales. Family: Rosaceae. No children of Antelope Bitterbrush Purshia tridentata found. Murray [ ] found that postfire yields of antelope bitterbrush were less after a spring fire than a fall fire, and speculated that sprouting after a spring fire would be greater than after summer fire. When soils are moist at the time of the burn, the root crown incurs less damage.
Additionally, sprouting is more likely if fires are followed by rain [ 36 , , ]. Clark and others [ 52 ] found mortality was higher on watered fall-burned plots than on spring-burned plots. More plants sprouted following a light August burn than a light July burn in southern Idaho, which the authors attributed to greater carbohydrate storage in the roots in August.
Most moderately and heavily burned plants were killed [ ]. High fuel consumption increases antelope bitterbrush mortality and therefore favors seedling establishment [ 36 , 44 ]. A low intensity, high frequency fire regime favors sprouting, whereas higher intensity, less frequent fires favors seedling regeneration [ 78 ]. Driver [ 77 ], who found high sprouting rates on his study plots in Washington, suggests that successfully sprouting columnar ecotypes may have been selected on habitats with high fire frequencies.
According to Agee [ 1 ], nonsprouting antelope bitterbrush is now widespread in ponderosa pine ecosystems due to fire exclusion. Soil texture affects the thermal transfer properties of soil and therefore the ability of antelope bitterbrush to sprout from undamaged underground buds [ ]. Fire is more damaging to antelope bitterbrush on fine-textured calcareous soils than on coarse-textured, well-drained soils [ 37 ]. In several Oregon burns, Driscoll [ 75 ] found plants on northerly slopes with loose, coarse-textured, nonstony soils without pumice sprout best.
Plants on fine-textured, stony soil sprouted poorly. Cheatgrass invasion has increased the amount of fine fuels in big sagebrush-antelope bitterbrush grasslands, and antelope bitterbrush is not adapted to the more frequent, high severity fires resulting from increased fuel loads. Cheatgrass may outcompete antelope bitterbrush after fire [ ].
Murray [ ] found prescribed burned plots in Idaho had less than half the average yields of antelope bitterbrush compared to unburned plots. He concludes that vigorous competition from grasses may have decreased seedling establishment of antelope bitterbrush. Antelope bitterbrush seeds germinate and grow on mineral soil exposed by fire [ 35 , ]. In the Black Hills of South Dakota, antelope bitterbrush survival was measured 10 years after planting on a burned site and in an unburned, open stand of ponderosa pine [ 74 ].
Establishment from seed and containerized seedlings was higher on burned plots: Percent survival on: Seeded Planted from containerized seedlings Burned However, when fire is completely excluded from ponderosa pine for a long time, antelope bitterbrush becomes decadent [ 10 , ].
Its density declines because dying plants are not replaced [ 43 , 44 , ]. Frequent Indian-set fires probably favored grasses over antelope bitterbrush on most sites. On dry or stony sites, however, fires would not have carried as well, and antelope bitterbrush probably dominated such sites [ 8 ]. According to Driver and Winston [ 78 ], frequent, low-intensity wildfire in ponderosa pine communities of north-central Washington encouraged sprouting and maintained antelope bitterbrush as a community dominant.
Plants surviving the treatments had greater live biomass and palatability than unburned plants [ 9 ]. Following spring fire, only two antelope bitterbrush seedlings were found on study plots. Browsing was heavy on these sites and may have reduced available seeds. Twelve percent of burned plants sprouted the first year after fire. Annual growth rate of antelope bitterbrush was greater on burned plots compared to unburned plots for the first 2 years after fire [ 18 ].
Blaisdell [ 28 ] found some antelope bitterbrush sprouting following prescribed burns in Idaho, but total production of antelope bitterbrush was far below prefire levels. Sprouting bitterbrush dominated big sagebrush 9 years after fire, since it outgrew big sagebrush regeneration from seed. Twelve years after the burn, antelope bitterbrush production was still lower on burned plots compared to unburned plots.
In western juniper-antelope bitterbrush associations, antelope bitterbrush appears more vigorous where fire has killed junipers [ 44 , ]. In dry Douglas-fir habitat types, antelope bitterbrush requires fire to reduce competition from conifer seedlings [ 35 ]. Prescribed fire in mesic forest communities maintains a subclimax community type and therefore encourages antelope bitterbrush establishment [ 44 ].
Antelope bitterbrush recovery from fire often takes too long for fire to be a useful tool in managing antelope bitterbrush [ 15 , 49 , , ]. Gruell [ ] claims a fire frequency of 5 to 20 years would result in sparse distribution and low density of antelope bitterbrush. Driver and Winston [ 78 ] found fire recovery in the Craters of the Moon National Monument to take 15 to 20 years.
Barrington and others [ 14 ] claim antelope bitterbrush density remains lower than prefire density for over 30 years in ponderosa pine communities on the eastern slope of the Cascade Range in Washington.
Wright [ ] reported that antelope bitterbrush was not fully recovered 27 years after a fire in a ponderosa pine community on the Warm Springs Reservation, Oregon. Rodent-cached seeds are an important source of antelope bitterbrush regeneration after fire [ 44 , ].
Rodent caches near or in a burned area may suffer less from seed predation following a fire because of reduced cover for rodents [ 56 ]. In British Columbia, Demarchi and Lofts [ 73 ] evaluated the nutritional content of antelope bitterbrush following fire. They concluded that there was a 3-year increase in nitrogen; a 2-year increase in calcium; a 1-year increase in phosphorus, potassium, and zinc; a decrease in copper; and no change in manganese.
Three prescribed burned sites within 30 km of Encampment, in south-central Wyoming. The sites were dominated by antelope bitterbrush Purshia tridentata , mountain big sagebrush Artemisia tridentata ssp. Common graminoids included bluebunch wheatgrass Pseudoroegneria spicata , spike fescue Leucopoa kingii , needle-and-thread grass Hesperostipa comata , and Ross sedge Carex rossii.
Areas surrounding the study sites support quaking aspen Populus tremuloides and lodgepole pine Pinus contorta communities. Climate is semi-arid. The authors describe the study sites as high elevation and mesic, which is not typical antelope bitterbrush habitat. The region's average precipitation is 38 cm; average temperature is 5? At approximately 2, meters, the study sites were slightly higher in elevation than regional climate stations, so they are probably wetter and cooler than these averages.
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