TY - JOUR T1 - Interactions of factors affecting seedling recruitment of Blue oak (Quercus douglasii) in California JF - Ecology Y1 - 1989 A1 - Borchert, M. I. A1 - Davis, F. W. A1 - Michaelsen, J. A1 - Oyler, L. D. KW - acorn blue oak cattle exclosures gophers interaction mice predation seedling woodland classification and regression tree (CART) hierarchical cluster analysis stepwise logistic regression American Canyon Agua Escondido San Luis Obispo County northness inde VL - 70 N1 - this paper is the origin of the northness index as an estimate of relative solar insolation derived from slope and aspect (azimuth from north) ER -