Oak cover types comprise half of the forestlands in the eastern United States. There is a great desire to sustain these highly valued forests. Unfortunately, reports of the successional replacement of oak are all too common, as they are throughout the world. Sustaining the oak resource requires the ability to both regenerate and recruit oak into the overstory as dominant mature trees. Too often...

Tree decline is a physiological phenomenon resulting from climatic disturbances that involves damage to forest ecosystems. This study examined the effects of tree on nutrient concentrations in leaves, bark, and wood Persian oak (Quercus brantii) trees. Trees were categorized by severity (healthy, slight, moderate, severe decline). Leaves collected middle outer parts crowns. Bark samples taken a...

We assessed dietary preference of 14 captive Blue Jays (Cyanocitta cristata) for different food types under different conditions of availability. In four separate feeding trials, we provisioned jays with the following: Trial 1, two nuts each of white oak (Quercus alba), pin oak (Q. palustris), black oak (Q. velutina), northern red oak (Q. rubra), and shagbark hickory (Carya ovata); Trial 2, two...

Overstory and understory data were collected over a 15-year period (1996–2011) before and after seed tree logging in 1996 and an accidental wildfire in 2006 in a young developing mixed-oak forest in central Pennsylvania. The mature forest overstory was dominated by chestnut oak (Quercus montana) followed by northern red oak (Quercus rubra), black oak (Quercus velutina), scarlet oak (Quercus coc...

Several countries of Asia, including Malaysia, have in recent years experienced spectacular economic growth and social change. This, together with declining fertility rates and mortality rates, and accompanying increased expectation of life at birth have resulted in rapid population ageing of these countries. However, relative to the developed countries, where fertility and mortality declines, ...

1% in 2000. Although the objective was far from being reached (the current rate being close to 2%), in 2000 Mexico had 53 million inhabitants fewer than it would have had if fertility had remained at its 1970 level. The population pyramids of 1930, 1970 and 2000 clearly illustrate this dynamics (Figure 2). In 1930 the population was beginning to recover from the aftereffects of the Revolution a...

The distribution of the Middle Spotted Woodpecker (Leiopicus medius) is restricted to mature deciduous forests with large trees, mainly oaks (Quercus spp.). Intensive forest management resulted in loss many suitable habitats, thus resulting a decline population this species. This study aimed identify parameters foraging sites breeding season (April June) and non-breeding (other months). researc...