The interactions between many species are structured in a geographic mosaic of populations among which selection is divergent. Here we tested the hypothesis that such a geographic selection mosaic arises for common crossbills (Loxia curvirostra) feeding on seeds in the cones of Aleppo pine (Pinus halepensis) because of geographic variation in the occurrence of European red squirrels (Sciurus vu...

As humans continue to alter ecosystems through land-use activities, revegetation projects will be one important way to restore or maintain impacted plant communities. Certain species, such as knobcone pine (Pinus attenuata Lemmon), have been used in some revegetation projects because of their preferable traits. Information on seed production and viability is critical to planning effective proje...

Background:Antioxidant effects of cypress cones extract have been previously demonstrated. In this study, the protective effect of cypress cones extract was investigated. Gentamicin, an aminoglycoside antibiotic administrated for the treatment of gram-negative bacteria infections, was used for nephrotoxicity induction. Methods: In this study, 60 wistar male ra...

Pine cones are well known natural actuators that can move their scales upon humidity gradient. The mechanism manifests itself through a displacement easily observable by the naked eye, but coupled with stress generation. In ancient Egypt, wooden wedges were used to break soft blocks of stone by the generated swelling stress. The purpose of the present study is to evaluate the ability of pine co...

Relatively few animal species extract seeds from closed conifer cones because of the forces required to spread apart or penetrate the woody scales. Those species that forage on seeds in closed cones tend to forage selectively, and therefore act as selective agents on cone structure. However, little is known about the foraging preferences and thus phenotypic selection that is exerted on conifers...

Spatial and temporal variability in cone production may influence post-disturbance succession, yet it is not well understood. We sampled 15year old lodgepole pine (Pinus contorta var. latifolia) stands (n = 16) that regenerated naturally after the 1988 Yellowstone fires and varied in stand density (566–545,200 stems ha ) and elevation to quantify and explain variation in cone production. Among ...

Steady state gene frequencies around a suming single gene inheritance and no dompocket of differential fitness have been forinance, Teich (1970) demonstrated that mulated by Hanson (1966) in a generalizapopulations of both jack pine and lodgepole tion of the work of Haldane (1948). A pine (Pinus contorta Dougl.) fit Hardypocket of differential fitness would result Weinberg expectations. The ele...

– The rare and unique Hispaniolan White-winged Crossbill (Loxia Ieucoptera megaplaga) is endemic to the mountains of Hispaniola. It is specialized for harvesting seeds from the cones of Pin us occidentals, and is dependent on the perpetual production of cone crops. Because large cone crops are produced only once every three or so years in any single area, crossbills require large areas to susta...

Seed production was studied in cones from 18 clones of radiata pine (Pinus radiata D. Don) replicated within and between four contrasting sites. At one site which was phosphate-deficient, number of full seeds per cone, along with cone volume #nd mean seed weight, was about one-third less than elsewhere. Empty seeds, although never completely absent, were prevalent only in occasional cones. Such...