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<br />of cottonwood seedlings. By the end of the third growing season, cottonwood had attained a <br />height of 3 to 5 feet, successfully overtopping salt cedar seedlings which had germinated at the <br />same time. <br /> <br />Several factors are crucial to the germination and survival of cottonwood and willows <br />including available seed source(s); timing of seed release; competition; availability of suitable <br />substrate; the depth, duration, expected frequency, and seasonal timing of inundation; and the <br />rapidity of descending water levels (Mahoney and Rood 1993). Opportunities for natural <br />regeneration of plains cottonwoods and willows along the Arkansas River may exist; however, <br />specific areas with requisite attributes were not identified as part of the present study. <br />Additional field surveys and more accurate hydraulic modeling would be required to determine <br />if and where suitable areas occur. <br /> <br />While natural regeneration of riparian vegetation may be most desirable and, often, <br />inexpensive, most restoration efforts along Southwestern streams and rivers have employed <br />plantings. <br /> <br />Riparian Restoration Plantings <br /> <br />Stands of several species of cottonwoods have been successfully reestablished through <br />pole plantings. Dormant, 15- to 20-foot tall poles are cut from natural stands or nurseries <br />during the late winter. Holes to receive poles are drilled with a soil auger (often gas-powered <br />and tractor-mounted) to a depth sufficient to reach the groundwater surface or at least the <br />capillary fringe. Poles are inserted and the holes backfilled by hand. Poles will generate rapid <br />root growth if they are planted before bud break and their lower ends are sufficiently wet. <br />Supplemental irrigation usually is not required. Best suited to successful pole planting are <br />those areas where the groundwater is within 5 feet of the surface and soils are primarily sandy <br />without large stones or cobbles. Following successful establishment, the above-ground growth <br />rate can be as much as 5 feet per year. Survival rates of 80 to 90% after the third growing <br />season are commonly achieved. Plantings may require insecticidal treatment during the first <br />year or two to control cottonwood beetle damage. Costs average about $20 per pole (including <br />materials, labor, and administration costs). <br /> <br />Sandbar and peach-leaf willows can be easily established through whip plantings. <br />Dormant whips cut from existing stands are hand-planted in suitably moist areas during spring. <br />Given a suitable local source of willow, labor may be the only cost incurred. Willow planting <br />is an excellent restoration activity to utilize volunteer labor. <br /> <br />Soils with high salinity are not viable areas for the establishment of cottonwood or <br />willow. Generally, soils with electrical conductivity greater than 3 mmhoslcm (approximately <br />980 ppm NaCl) are considered too saline for successful woody plant establishment. These <br />areas along the Arkansas River are best suited for saltgrass and alkali sacaton plantings. <br /> <br />Establishment of riparian grasses and herbaceous vegetation usually follows standard <br />agricultural practices. Areas intended for restoration planting may require disking, scarifying, <br /> <br />41 <br />