VARIATION AMONG GREEN ASH OF DIFFERING GEOGRAPHIC ORIGINS OUTPLANTED IN KANSAS

Green ash trees from 18 provenances were planted in a seed-source test in 1971 near Manhattan, Kan- sas, in the central part of the Great Plains Region. Most seed sources were from north of the planting site. After 20 years, growth measurements revealed that the tallest trees were from more southerly sources and/or those near the planta- tion site. Trees from moderate distances north (150 miles) of the planting site also showed adequate growth. Height and dbh age-age correlations were highly significant and increased when compared to age measurements of earlier intervals. Throughout the Great Plains, green ash (Fraxinuspennsylvanica) is planted in shelterbelts and farmstead woodlots, as well as in urban settings. Its natural range extends throughout the eastern United States from eastern Texas to eastern Montana and south central Canada. Adaptation to such an extensive geographic range implies the presence of much genetic variation, which can be exploited for genetic improvement of the species (5,8). For example, Abrams et al. (1) reported that South Dakota seedlings had higher net photosynthesis and leaf conductance than New York seedlings. Seedlings from a xeric South Dakota location generally had smaller and thicker leaves, while seedlings from a mesic New York seed source had thinner and larger leaves. Van Deusen and Cunningham (6) found that trees of northern sources shed their leaves before those of southern sources in a North Dakota plantation. In 4 Western Gulf region plantations, Hendrix and Lowe (2) observed substantial variations in growth and wood specific gravity among 12-year-old green ash from different provenances. In a Mississippi plantation, Wells (7) demonstrated that 5- and 10-year-old trees from southern sources grew faster than those from northern sources. High within-stand variation also was noted. Ying and Bagley (8) reported that age-4 green ash trees from Kansas and Oklahoma provenances suffered mortality from winter damage in a North Dakota plantation, Kansas-source trees survived well yet had the poorest height growth in South Dakota, and Oklahoma trees had the poorest growth in central Nebraska. However, no differences were noted among green ash from 43 provenances in resistance to the ash borer, Podosesia syringae, according to Santamour and Steiner (3). The purpose of this paper is to report the re- sults of a 20-year Kansas study of green ash from various provenances.