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The Association Of Seed And Cone Predator Populations And Cone Crop Production In Engelmann Spruce, Dawn E. Cameron
The Association Of Seed And Cone Predator Populations And Cone Crop Production In Engelmann Spruce, Dawn E. Cameron
T.W. "Doc" Daniel Experimental Forest
Engelmann spruce (Picea engelmannii Parry ex Engelm.) exhibits cone crop periodicity, producing seed in a cyclic pattern. Variation in seed production has been noted between individuals of a population, but synchronization on a large scale is common. The theory that ultimately these periodic large cone crops have resulted from the selective pressures of seed and cone predators, referred to as the predator satiation hypothesis, is considered. Assuming predator pressures have operated over evolutionary time to select for periodic synchrony, associations between seed and cone predators and cone crop production levels were anticipated. These potential consequences of predator satiation were examined. …
Influence Of Size Of Cone Crop On Diameter Growth Of Engelmann Spruce (Picea Engelmannii Parry), Herbert Hager
Influence Of Size Of Cone Crop On Diameter Growth Of Engelmann Spruce (Picea Engelmannii Parry), Herbert Hager
T.W. "Doc" Daniel Experimental Forest
The influence of the average annual cone crop of 170 Engelmann spruce trees on the average basal area increments over a period of 23 years was tested in climatically compensated and uncompensated multiple regression models. In addition, three outstanding cone producing trees were analyzed with the climate compensating model. The cone production of the individual trees were analyzed for the effect on each basal area increment without climatic compensation. A multiple regression model with bimonthly climatic parameters for the growing season, yielded the best prediction (R2 = 98%) of annual basal area increment from the independent parameters among which was …