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...

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...

Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree species' potential for surviving future aggravated environmental conditions is rather demanding. The ai...

-A model was developed that predicts the probability of survival for individual shortleaf pine (Pinus echinatu Mill.) trees growing in even-aged natural stands. Data for model development were obtained from the first two measurements of permanently established plots located in natural ly occurring short leaf pine forests on the Ouachita and Ozark National Forests in western Arkansas and eastern...

Studies of predator-prey interactions have found that geographically structured coevolution has played an important role in the adaptive diversification of crossbills (Loxia spp.). We extend those studies by considering common crossbills (L. curvirostra) in the Mediterranean where they rely on seeds in the cones of black pine (Pinus nigra). On the continent, where tree squirrels (Sciurus vulgar...

Future forests are being shaped bychanging climate and disturbances. Climate change is causing large-scale forest declines globally, in addition to distributional shifts of many tree species. Because environmental cues dictate insect seasonality and population success, climate change is also influencing tree-killing bark beetles. The mountain pine beetle, Dendroctonus ponderosae, is a major dis...