Daily precipitation patterns were compared to the variation in miserotoxin concentration of Columbia milkvetch (timber milkvetch) sampled sequentially during the spring and summer of 1973 and 1974. On rough fescue grasslands, the substantial increase in rainfall during the April-to-August period of 1974 not only extended toxicity intervals but also increased miserotoxin levels during the prebud growth stage. A large-scale rain storm induced miserotoxin synthesis during the pod stage. Greater soil moisture-holding capacity at one grassland experimental plot prevented a rapid decline in miserotoxin levels when drought conditions developed. In contrast, the toxicity trends on Douglasfir forest sites did not show a response to variations in precipitation and toxin differences between local sites were not significant. Consequently, a predictability equation was developed for Columbia milkvetch toxicity in Douglasfir forests on Gray Luvisolic soils. This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries. The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020
Scholarly peer-reviewed articles published by the Society for Range Management. Access articles on a rolling-window basis from vol. 1, 1948 up to 5 years from the current year. Formerly Journal of Range Management (JRM). More recent content is available by subscription from SRM.