In pine wilt disease (PWD), embolized tracheids arise after virulent pine wood nematodes (PWN), Bursaphelenchus xylophilus, invade the resin canal of pine tree; infected pine trees finally die from significant loss of xylem water conduction. We used a compact magnetic resonance imaging system with a U-shaped radio frequency (rf) probe coil to reveal the developmental process of the xylem dysfun...

In 1990–1991, Diprion pini extensively defoliated Scots pine (Pinus sylvestris L.) trees in Lauhanvuori National Park in southwestern Finland. Many trees lost all their foliage, while others had ca. 10 % foliage left after the second year of defoliation. Outside the national park, many nearby stands were also heavily defoliated in 1990, but were sprayed with diflubenzuron (Dimilin®) in 1991. Th...

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...

One hundred and twenty-three open-pollinatedfamilies from 38 stands of Virginia pine were tested in Oklahoma. Height and survival data at age 5 for two Christmas tree plantations and at age 5 and 7 for two progenytest plantations were analyzed In the Christmas tree tests, four Stan& ftom North Carolina, three from Tennessee, andone each from Alabama, Kentucky, South Carolina, and Virginia were ...

The tree-killing mountain pine beetle (Dendroctonus ponderosae Hopkins) is an important disturbance agent of western North American forests and recent outbreaks have affected tens of millions of hectares of trees. Most western North American pines (Pinus spp.) are hosts and are successfully attacked by mountain pine beetles whereas a handful of pine species are not suitable hosts and are rarely...

Abstract Mexico ranks 5 th in worldwide resin production. Pinus oocarpa is the most widely tapped pine tree Mexico. Michoacán (central-western Mexico) first nationwide state producer of resin. Despite P. relevance, there no genetic improvement program country for We evaluated degree control growth, anatomical traits, yield, and correlation among them at an early age (five-years-old six resin, t...

Mountain pine beetle, Dendroctonus ponderosae Hopkins, is the most significant mortality agent in pine forests of western North America. Silvicultural treatments that reduce the number of susceptible host trees, alter age and size class distributions, and diversify species composition are considered viable, long-term options for reducing stand susceptibility to mountain pine beetle-caused tree ...

Longleaf pine (Pinus palustris Mill) was once the main southern pine species found throughout the southeastern United States, encompassing approximately 38 million hectares (6). After nearly complete destruction of the longleaf pine ecosystem, restoration efforts in recent years have caused resurgence in the planting of longleaf pine on many state and federal lands (14). Many factors have signi...

Whitebark Pine (Pinus albicaulis) plays an integral role in the Greater Yellowstone Ecosystem (GYE). It has been often referred to as a keystone species due to the extensive changes that the ecosystem would undergo if the species were to be lost. Attributed to white pine blister rust (Cronartium ribicola) infection and mountain pine beetles (Dendroctonus ponderosae), the decline of the whitebar...

Resin acids in many pulp mill effluents are primary sources of toxicity to fish. Inconsistent biological detoxification of chlorinated and nonchlorinated resin acids in secondary treatment of pulp mill effluents is a continuing source of concern. An alternative approach to effluent detoxification is to remove or modify the toxic compounds present in wood chips prior to pulping. Results from exp...