We tested the effects of eight site preparation treatments on early growth and survival of container-grown longleaf pine (Pinuspalustris Mill.) seedlings. Treatments included an untreated check, six combinations of two initial vegetation control treatments (chopping or herbicide) with three planting site conditions (flat [no additional treatment], mounding, or bedding), and a more intense treat...

1 Mountain pine beetle (Dendroctonus ponderosae) is an important disturbance agent in Pinus ecosystems of western North America, historically causing significant tree mortality. Most recorded outbreaks have occurred in mid elevation lodgepole pine (Pinus contorta). In warm years, tree mortality also occurs at higher elevations in mixed species stands. 2 Mountain pine beetle’s relative preferenc...

Etiological studies to determine the cause of decline and death of Pinus spp. in Delaware were initiated in 1980. The pinewood nematode, Bursaphelenchus xylophilus, was found to be the major canse of mortality in Japanese black pine (Pinus thunbergii). When inoculated into healthy 5-yr-old Japanese black pines, B. xylophilus produced typical decline symptoms observed in the field. The xylophilo...

In many pine species (Family Pinaceae), ovulate cones structurally resemble a turbine, which has been widely interpreted as an adaptation for improving pollination by producing complex aerodynamic effects. We tested the turbine interpretation by quantifying patterns of pollen accumulation on ovulate cones in a wind tunnel and by using simulation models based on computational fluid dynamics. We ...

Background Conifer clonal forestry as a form of plantation forestry has great potential advantages. However, vegetative propagation of conifers, especially that of mature trees, is quite problematic. These species also are most recalcitrant objects for cultivation in vitro. For this reason the development of an effective system for clonal micropropagation of some conifers is still an important ...

The pine shoot beetle, Tomicus piniperda (L.), is an exotic pest that has become established in North America. Discovered in Ohio in 1992, it has since been found in at least 13 states and parts of Canada. The beetle can cause significant growth loss in pines, and it represents a potential threat to trees in areas where it has not yet become established. To evaluate this threat to native pines,...