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...

Surveys for mountain pine beetle are undertaken across a range of scales to provide forest managers with up-to-date information regarding the location, extent, and numbers of infested trees. Remote sensing provides new opportunities to detect and map mountain pine beetle damage to inform management and mitigation decisions. The key to using remotely sensed data is to identify how this new infor...

We evaluated the long-term (1995-2008) trends in foliar and sapwood metabolism, soil solution chemistry and tree mortality rates in response to chronic nitrogen (N) additions to pine and hardwood stands at the Harvard Forest Long Term Ecological Research (LTER) site. Common stress-related metabolites like polyamines (PAs), free amino acids (AAs) and inorganic elements were analyzed for control,...

We investigated the cellular responses of stem tissues of mature Scots pine (Pinus sylvestris L.) trees to inoculations with two fungal pathogens. The bark beetle vectored fungus, Leptographium wingfieldii Morelet, induced longer lesions in the bark, stronger swelling of polyphenolic parenchyma cells, more polyphenol accumulation and increased ray parenchyma activity compared with the root rot ...

A new method for estimating fractal dimension of tree crowns from digital images is presented. Three species of trees, Japanese yew (Taxus cuspidata Sieb & Zucc), Hicks yew (Taxus × media), and eastern white pine (Pinus strobus L.), were studied. Fractal dimensions of Japanese yew and Hicks yew range from 2.26 to 2.70. Fractal dimension of eastern white pine range from 2.14 to 2.43. The differe...

The sharp temperature changes in nature (e.g., forest fires, ice, and snow) can cause mechanical damage to trees and bamboo. The mechanical properties of Mongolia Scotch pine (Pinus sylvestris L. var. mongolica) and Moso bamboo (Phyllostachys edulis) were investigated by a three-point bending test with a repeated thermal shock process (i.e., sudden changes of temperature). The experimental resu...

The current epidemic of the mountain pine beetle (MPB), an indigenous pest of western North American pine, has resulted in significant losses of lodgepole pine. The leading edge has reached Alberta where forest composition shifts from lodgepole to jack pine through a hybrid zone. The susceptibility of jack pine to MPB is a major concern, but there has been no evidence of host-range expansion, i...

The transmission of Bursaphelenchus xylophilus from Monochamus alternatus males to Pinus densiflora trees via oviposition wounds has been determined. Nematode-infested males, with mandibles fixed experimentally to prevent feeding, were placed for 48 hours with pine bolts containing oviposition wounds that had been made by nematode-free females. After removal of the nematode-infested males, the ...

-Top grafting is used to accelerate the breeding cycle of loblolly pine (Pinus taeda L). Scions, collected from seedlings as young as 1 year from seed, are grafted onto mature interstocks of the same or a related species. Male and female strobili production often begins 1 or 2 years after grafting, thus potentially decreasing the generation time by several years over conventional accelerated br...

Crown and canopy structurecorrelate with growth efficiency and also determine stem size and taper as described by the uniform stress principle of stem formation. A regression model was derived from this principle that expresses basal area increment in terms of the amount and vertical distribution of leaf area and change in these variables during a growth period. This model was fit t o data coll...