At the forest landscape/region level, based on annual Forest Inventory and Analysis plot data from 1999 to 2010, oak decline and mortality trends for major oak species (groups) were examined in the Ozark Highlands of Arkansas and Missouri. Oak decline has elevated cumulative mortality of red oak species to between 11 and 15 percent in terms of relative density and basal area of standing dead oa...

A robust understanding of phloem functioning in tall trees evades us because current methods for collecting sap do not lend themselves to measuring actively photosynthesizing canopy leaves. We show that Raman spectroscopy can be used as a quantitative tool assess sucrose concentration leaf samples. Specifically, we found predict physiologically relevant concentrations (adjusted R2 0.9) frozen e...

Leaves are the largest component of forest litter. Their decomposition rate depends mainly on plant species, leaf chemical composition, microorganism biodiversity, and habitat conditions. It is known that herbivory by insects can modify composition leaves, such as through induction. The aim this study was to determine whether related susceptibility species insect feeding how damage affects rate...

BACKGROUND Oak moss absolute, an extract from the lichen Evernia prunastri, is a valued perfume ingredient but contains extreme allergens. OBJECTIVES To compare the elicitation properties of two preparations of oak moss absolute: 'classic oak moss', the historically used preparation, and 'new oak moss', with reduced contents of the major allergens atranol and chloroatranol. PATIENTS/MATERIA...

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...

Acknowledgements: We thank John McMillan, David Laibson, Colin Camerer, and three anonymous referees for useful comments. We thank Mandar Oak and Rosa Stipanovic for research assistance. For financial support, Frederick and Loewenstein thank the Integrated Study of the Human Dimensions of Global Change at Carnegie Mellon University (NSF Grant SBR-9521914), and O’Donoghue thanks the National Sci...

Savannas’ defining feature is a scattered tree layer. However, woody plants have encroached savannas throughout the world, altering tree densities and potentially modifying regeneration dynamics. We used a replicated large-scale restoration experiment with Midwestern oak savannas (USA) to understand spatial patterns of regeneration by the dominant overstory species, Quercus alba. Q. alba is not...