In the southeastern United States, drought can pose a significant threat to forests by reducing the amount of available water, thereby stressing trees. Destructive changes in crown conditions provide the first visible indication of a problem in a forested area, making it a useful indicator for problems within an ecosystem. Forest Health and Monitoring (FHM) and Palmer’s Drought Severity Index (...

this study was aimed to assess the causes of the structural decline in the renewal rate of apristine oak forest close to rome (central italy) by analyzing long-term measurements of the water budget in open and fenced areas. despite dry climate conditions in the area, long-term soil moisture measurements at 100 cm soil depth indicated that an enough large amount of water is available to oaks dur...

Zagros vegetation zone is one of the most important forest regions in Iran, which consists of a diverse group of arboreal species, especially oaks (Quercus spp.). Ilam province located in west of Iran and in Zagros vegetation zone which has 641000 ha of oak forests that its dominant species is Persian oak (Q. brantii). Oak trees decline is a complicated phenomenon that may result from different...

The composition and temporal variation in species recruitment were examined in relation to annual dendrochronological data to determine the historical development and successional history of an old-growth mixed-oak (Quercus) forest in northern Virginia, USA. A ridge site in the upland Piedmont, along the Potomac River, was used to survey the old-growth forest, which is dominated by Quercus alba...

Seedlings of cherrybark oak (Quercus pagoda Rafinesque), Nuttall oak (Quercus nuttallii Palmer) and overcup oak (Quercus lyrata Walter) were grown under two light levels, partial (20 percent) or full sunlight, to study physiological acclimation of leaves to low light availability. Shifts in leaf morphology were noted for seedlings raised beneath partial sunlight, and photosynthetic light respon...

Snags provide an important resource for a rich assemblage of cavity-nesting birds in the southwestern United States. To expand our knowledge of snag use by cavity-nesting birds in this region, we documented characteristics of snags with and without excavated cavities in mixed-conifer and ponderosa pine (Pinus ponderosa Dougl. ex Laws) forest in north-central Arizona. Snags were sampled in 113 s...