Effects of thermoperiod on the early growth of red alder from different elevations and geographic sources

摘要: approved: Signature redacted for privacy. Kim K. Ching This study was designed to help elucidate what differences, if any, exist within the species Alnus rubra Bong., grown naturally at various elevations and locations throughout Pacific Northwest coastal Alaska. Increasing importance of species, including both economic silviculture values, prompted investigation into early growth red alder, an area in which detailed information is lacking. Two areas that were established included, first, elevational transect from Newport toMarys Peak Coast Range Oregon and, second, a ten geographic sources located range rubra, Both phases this conducted under three regimes involving use 16 hour photoperiod thermoperiods (day-night temperatures are: 21°, 16°C; 10 10°C 21°C). The Transect Study showed differences between alder conelets (weight size) seeds (weights germination) different be significant 1% level. effect lower thermoperiod (10°, 10°C) reducing rate germination also shown. No found seedlings repre senting elevations, other characteristics (height, diameter leaf dimension). Geographic Study, wildlings supplied by U. S. Forest Service, concerned primarily with seedling height size. Significant but, because limited number available, reliability data accurately express variation these questionable. single tested environment but results opposite those obtained Study. In cold condition 10° C) significantly greater than conditions. shorter regimes. Effects Thermoperiod on Early Growth Red Alder Different Elevations Sources