Scans of slash pine wood chips infested with pine wood nematodes showed coiled aggregates of 5-10 nematodes in the axial resin canals, and 1-2 nematodes folded in the radial resin canals. Observations of the pine wood nematode by SEM showed the head to be offset with six labial lobes. A smaller circle of six inner lobes surrounded the stoma. A single labial sensillum was observed on each of the...

The analysis of the tree radial growth response to climate is crucial for dendroclimatological research. However, the response relationships between tree-ring indices and climatic factors at different timescales are not yet clear. In this study, the tree-ring width of Huashan pine (Pinus armandii) from Huashan in the Qinling Mountains, north-central China, was used to explore the response diffe...

The effects after 25 years of moose browsing on Scots pine stands in Lahemaa National Park were evaluated, emphasizing economic damage. A re-evaluation in 2001 examined stands that had been evaluated in 1975–1976. Moose damage significantly affected the tree species composition which changed over time as pine dominance increased and the number of mixed stands declined. The smaller proportion of...

Shortleaf pine-oak-hickory woodlands provided the principal vegetation cover in the Tallahassee Red Hills prior to land clearing for plantation agriculture in the 19th century. Ample historical documentation and extant remnants of that community, including old-growth, support this conclusion. This woodland was maintained by surface fires and consisted principally of open stands of shortleaf pin...

Conifer defenses against bark beetle attack include, but are not limited to, quantitative and qualitative defenses produced prior to attack. Our objective was to assess host defenses of lodgepole pine and ponderosa pine from ecotone stands. These stands provide a transition of host species for mountain pine beetle (Dendroctonus ponderosae; MPB). We asked two questions: (1) do the preformed quan...

To test the hypothesis that drought predisposes trees to insect attacks, we quantified the effects of water availability on insect attacks, tree resistance mechanisms, and mortality of mature piñon pine (Pinus edulis) and one-seed juniper (Juniperus monosperma) using an experimental drought study in New Mexico, USA. The study had four replicated treatments (40 × 40 m plot/replicate): removal of...

AKSTRACT Dcrcriloclo~~~r~s Jj-or&r/is Zim~nernr:tn is a major disturbance agent in Alnericnn pine forests, but attack prefcrcnccs for various host spt:cic:s, and their relative suitability for reproduction, are poorly knowi). We studied patterns of beetle attack and reproduction during an infestation of stands contairiing Virginia pine and lol~lolly pine. Nearly all Virginia pine were attacked ...