there is an impression that basal cell carcinomas (bcc) occurring in younger population may be of more invasive behavior in comparison to those arising in older patients. the purpose of this study was to investigate this hypothesis by comparing the histological types of bcc in a large cohort of young and old patients. a total of 287 histological reports and clinical records were evaluated. a co...

composition and structure of a three-storied fagus orientalis-dominated forest was investigated in the caspian forests, north of iran. circular sampling plots of 1000 m2 occupied by advance growth and natural regeneration were randomly chosen where the initial cuttings (with shelterwood aim) were performed. abundance of species at different growth stages and quality of seedlings and saplings we...

Forest dynamics were studied from 1993 to 1997 for individuals > 10 cm DBH in nine 1 ha permanent sample plots. They were established in natural flood plain forests located on the lower Ucayali river in the Peruvian Amazon. After inventories of three plots in each of three forest types, a light and a heavy felling treatment were applied to each of the two plots, while a third plot was kept untr...

A method was developed for estimating parameters in an individual tree basal area growth model using a system of equations based on dbh rank classes. The estimation method developed is a compromise between an individual tree and a stand level basal area growth model that accounts for the correlation between trees within a plot by using seemingly unrelated regression (SUR) to estimate the restri...

During the past decade, Swiss needle cast (SNC) damage has intensified in many Douglas-fir plantations in the Coast Range of Oregon, particularly along the immediate north coast. In plantations with severe symptoms, growth losses and reduced tree vigor are evident, but the magnitude of growth losses associated with varying intensities of damage is not known. A growth impact study was conducted ...

During the past decade, Swiss needle cast (SNC) damage has intensified in many Douglas-fir plantations in the Coast Range of Oregon, particularly along the immediate north coast. In plantations with severe symptoms, growth losses and reduced tree vigor are evident, but the magnitude of growth losses associated with varying intensities of damage is not known. A growth impact study was conducted ...

Homeostatic maintenance of gas exchange optimizes carbon gain per water loss. Homeostasis is regulated by short-term physiological and long-term structural mechanisms, both of which may respond to changes in resource availability associated with competition. Therefore, stand density regulation via silvicultural manipulations may facilitate growth and survival through mechanisms operating at bot...

Managers are often concerned about oak mortality in maturing mixed-oak forests, but they often lack explicit information about mortality risk for oaks that differ in species, size, crown class, competitive status, and growth rate. In eastern North America, tree species in the red oak group (Quercus Section Lobatae) are typically shorter lived than those in the white oak group (Section Quercus),...

Growth patterns of vertical stems in nine ponderosa pines from a stand in the southern Sierra Nevada were analyzed for recent changes due to stand dominance position, age, climate, and ozone exposure. Large positive correlations were found between increments in volume growth and basal area at d.b.h. The results indicated that patterns of wood distribution along the bole were associated with age...