GREAT BASIN NATIVE PLANT SELECTION AND INCREASE PROJECT 2011 PROGRESS REPORT USDA FOREST SERVICE, ROCKY MOUNTAIN RESEARCH STATION AND USDI BUREAU OF LAND MANAGEMENT, BOISE, ID APRIL 2012
COOPERATORS USDI Bureau of Land Management, Great Basin Restoration Initiative, Boise, ID USDI Bureau of Land Management, Plant Conservation Program, Washington, DC USDA Forest Service, Rocky Mountain Research Station, Grassland, Shrubland and Desert Ecosystem Research Program, Boise, ID and Provo, UT Boise State University, Boise, ID Brigham Young University, Provo, UT Colorado State University Cooperative Extension, Tri-River Area, Grand Junction, CO Eastern Oregon Stewardship Services, Prineville, OR Oregon State University, Malheur Experiment Station, Ontario, OR Private Seed Industry Texas Tech University, Lubbock, TX Truax Company, Inc., New Hope, MN University of Idaho, Moscow, ID University of Idaho Parma Research and Extension Center, Parma, ID University of Nevada, Reno, NV University of Nevada Cooperative Extension, Elko and Reno, NV University of Wyoming, Laramie, WY Utah State University, Logan, UT USDA Agricultural Research Service, Bee Biology and Systematics Laboratory, Logan, UT USDA Agricultural Research Service, Eastern Oregon Agricultural Research Center, Burns, OR USDA Agricultural Research Service, Forage and Range Research Laboratory, Logan, UT USDA Agricultural Research Service, Western Regional Plant Introduction Station, Pullman, WA USDA Natural Resources Conservation Service, Aberdeen Plant Materials Center, Aberdeen, ID USDA Forest Service, National Seed Laboratory, Dry Branch, GA USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR US Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, ID Utah Division of Wildlife Resources, Great Basin Research Center, Ephraim, UT Utah Crop Improvement Association, Logan, UT
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Project Title:
Adaptation of Roundleaf Buffaloberry (Shepherdia rotundifolia) to Urban Landscapes
Project Location:
University of Nevada Cooperative Extension, Reno, Nevada
Principal Investigators and Contact Information: Heidi A. Kratsch, Area Horticulture Specialist University of Nevada Cooperative Extension 4955 Energy Way, Reno, NV 89502 (775)784.4848, Fax (775)784.4881
[email protected] Chalita Sriladda, Graduate Assistant Department of Plants, Soils and Climate Utah State University 4820 Old Main Hill Logan, UT 84322-4820 Roger Kjelgren, Professor Department of Plants, Soils and Climate Utah State University 4820 Old Main Hill Logan, UT 84322-4820
Project Description: We study variation and diversity among intermountain western native plant species 1) to assure their stability and performance in home and commercial landscapes and 2) to assess their useful range for growers to establish a market for their stock. Shepherdia rotundifolia (roundleaf buffaloberry [Elaeagnaceae] is a Colorado Plateau endemic native to southern Utah and the Grand Canyon region of northern Arizona. The species is extremely drought tolerant and shows ornamental traits that make it an attractive candidate for use in urban home and commercial landscapes. The species attracts a variety of pollinators and other beneficial insects and is of value to wildlife as it provides food and cover for quail and small mammals. However, the species is difficult to keep alive in culture and is known to be short-lived in irrigated ornamental landscapes. Shepherdia argentea (silver buffaloberry) is widely distributed in riparian areas throughout the West and is common in naturalized designed landscapes in the Great Basin region. Its rangy appearance and thorny nature, however, render it less common for general ornamental use. With this project we characterize the natural habitat of S. rotundifolia in an effort to better understand its cultural requirements and report results of efforts to cross-hybridize with S. argentea, in hopes of creating an acceptable taxon for use in irrigated urban settings. Objective To characterize the natural habitat of Shepherdia rotundifolia and study its behavior in an irrigated setting to better understand its cultural requirements.
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Methods We characterized the edaphic, elevation, and light conditions experienced by S. rotundifolia at six representative sites in southern Utah. We also report 30-year historical weather patterns at the locations. We conducted common garden studies of S. rotundifolia using plants grown from seed collected at these sites to determine their physiological response to growth under irrigated landscape conditions. Finally, we performed reciprocal crosses of S. rotundifolia in the wild with its riparian relative, S. argentea, in an attempt to capture the aesthetic characters of S. rotundifolia and the tolerance to wet soils of S. argentea. Results and Discussion Elevation at the six sites ranges from 1500 to 2500 meters, and although the species tolerates drought, it can be found in areas with annual precipitation ranging from 200 to over 400 mm (Table 1). Once thought to be shade intolerant, we also found that plants in the highest elevation populations were mostly found beneath the canopy of ponderosa pine, the leaf litter of which also lowered the pH of the soils and increased their organic matter content (data not shown). Cultural trials of S. rotundifolia grown from seed in pots and common garden studies of the transplants showed that the species does not acclimate easily to conventional horticultural conditions and develops chlorosis of older leaves after one year of growth. This could be due to irrigation or soil conditions of the managed landscape setting or it could be a result of nutrient excess or deficiencies. The potassium content of soils beneath the canopies of the species in its natural habitat was higher than that of typical urban soils (data not shown). The leaf symptoms of cultured plants were consistent with potassium deficiency, although this was not confirmed. Roundleaf buffaloberry is a nitrogen-fixing species and thrives in low-nitrogen environments; it is also possible that nitrogen levels of the soils in our common garden study were too high, which would discourage association of plant roots with symbiotic soil bacteria and potentially weaken plants. Table 1. Site conditions characterizing S. rotundifolia populations studied. Average precipitation, maximum and minimum temperatures over a 30-year record at each site were obtained from existing weather stations closest to the sites. Average over 30 years (1981-2010) Precipitation Tmax Tmin Relative Light Population Elevation (m) (mm/year) °C °C Intensity (%) Tor-2500 2507 285 17 3 31 Tor-2300 2295 285 17 3 98 Tor-1600 1642 210 19 6 100 Natural Bridges 1342 327 17 4 99 Bluff 1342 199 17 4 94 Springdale 1188 409 25 9 88
We performed reciprocal crosses of S. rotundifolia with S. argentea and obtained a successful hybrid with intermediate leaf characters (Table 2). Hybrid plants grown from seed were transplanted in a common garden setting at Greenville Farm in North Logan, UT. Plant 148
physiological response (stomatal conductance and photosynthetic light response) indicated that the hybrid exhibits a physiological response more similar to S. argentea, a riparian species, than to S. rotundifolia. These data suggest that, while the hybrid retains some of the aesthetic appeal of S. rotundifolia, it may demonstrate a greater tolerance to regularly irrigated soils, a condition common in ornamental landscapes. Further study of physiological responses of the hybrid to drought conditions will better characterize optimal cultural requirements in managed settings. Table 2. Leaf morphological characteristics of Shepherdia rotundifolia, S. rotundifolia x argentea, and S. argentea grown from seed in pots (N=2). Species S. rotundifolia x Morphology S. rotundifolia S. argentea argentea Petiole length (mm) 5.3 10.5 7.0 Leaf length (mm) 24.0 39.3 42.5 Leaf width (mm) 23.0 24.5 12.7 Leaf length/width (mm) 1.0 1.6 3.4 Conclusion The interspecific hybrid between S. rotundifolia and S. argentea may be better adapted to and more acceptable in urban landscapes than either species alone.
Publications: Kratsch, H.; Sriladda, C. 2011. Morphological and genetic variation among common Utah globemallows. In: Great Basin Native Plant Selection and Increase Project FY2010 Progress Report. p. 28-31. http://www.fs.fed.us/rm/boise/research/shrub/projects/documents/2010_ProgressReport.pdf Sriladda, C. 2011. Ecophysiology and genetic variation in domestication of Sphaeralcea and Shepherdia species for the Intermountain West. Logan, UT: Utah State University. Dissertation. http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2027&context=etd
Presentations: Kratsch, H.; Sriladda, C. 2011. Morphological and genetic variation among common Utah globemallows. Great Basin Native Plant Selection and Increase Project Annual Meeting, 2011 February 22- 23, Salt Lake City, UT. http://www.fs.fed.us/rm/boise/research/shrub/GBNPSIP/GBNPSIPpresentations2011.shtml Kratsch, H.; Sriladda, C.; Kjelgren, R. 2011. Shepherdia rotundifolia: Preserving the species through urban landscape use. WERA1013: Intermountain Regional Evaluation and Introduction of Native Plants. 2011 October 8, Fort Collins, CO.
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Management Applications: A better understanding of the ecophysiology of Shepherdia rotundifolia will enable greater adoption of native plants in urban landscapes and will diversify such landscapes and provide pollinator and wildlife habitat. Anecdotally, this species also appears to be declining in its native habitat; preserving its genetic resources by adapting it for urban landscape use may be of benefit for its long-term survival.
Products: A list of intermountain regional native plant growers has been revised and sent to the WERA 1013 Intermountain Regional Evaluation and Introduction of Native Plants. http://www.uwyo.edu/wera1013/
Kratsch, H. 2011. Some good native plants for Great Basin landscapes. University of Nevada Cooperative Extension Special Publication 11-13. http://www.unce.unr.edu/publications/files/ho/2011/sp1113.pdf
A Master Gardener Native Plants Club has been established at the University of Nevada Cooperative Extension, including 30 Master Gardener volunteers from three counties in the Western Region of Nevada. Their goals are to select candidate species and to propagate and grow them for demonstration gardens around the region. Two gardens are currently in progress, one in Reno and one in Gardnerville. Fact sheet development and public education events are also goals of this group.
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