Northern red oak (Quercus rubra) and white oak (Quercus alba) are important components of high-quality mes1c s1tes and are essential as lumber species and hard mast producers. Regeneration of these species has been difficult, and their absence in newly regenerated stands is a major concern of foresters and wildlife biologists Several 1mportant biolog1cal tra1ts of oak species may contribute to ...

Human-caused changes in land use and land cover have dramatically altered ecosystems worldwide and may facilitate the spread of infectious diseases. To address this issue, we examined the influence of land-cover changes between 1942 and 2000 on the establishment of an invasive pathogen, Phytophthora ramorum, which causes the forest disease known as Sudden Oak Death. We assessed effects of land-...

ABSTRACT During 2001 to 2003, the transmission biology of Phytophthora ramorum, the causal agent of sudden oak death, was studied in mixedevergreen forest, a common forest type in northern, coastal California. Investigation of the sources of spore production focused on coast live oak (Quercus agrifolia) and bay laurel (Umbellularia californica), dominant hosts that comprised 39.7 and 46.2% of t...

Sudden oak death has emerged as a major threat to the oak forests of California. In oaks and tanoak, this disease complex consists of a previously unreported fungus-like pathogen, Phytophthora ramorum, insects (bark and ambrosia beetles), and a secondary fungus, Hypoxylon thouarsianum. Species monitored in this study were coast live oak (Quercus agrifolia), California black oak (Q. kelloggii), ...

Limited information and observations indicate that there are some significant amounts of hardwood residue resources now available in the Central Coast area. Experience gained from man­ aging and marketing eastern hardwoods is considered as our basis for dealing with western hardwood problems. Inventory of the oak resource is discussed as a preliminary requirement for management. In ad­ dition, ...

Different forest types exert essential impacts on soil physical-chemical characteristics by dominant tree species producing diverse litters and root exudates, thereby further regulating size and activity of soil microbial communities. However, the study accuracy is usually restricted by differences in climate, soil type and forest age. Our objective is to precisely quantify soil microbial bioma...

Fire, as a natural ecological disturbance factor in forest, this study located in the Marivan region, Northern Zagros forest, and western Iranian state of Kurdistan. In each burned and unburned area 30 circle sample plot (1000 m2) were collected by randomized–systematic method in the 100×200 m net (in total 60 plots). In every sample plot the kind of species, number of tree, the heig...

Timely and accurate identification of tree species by spectral methods is crucial for forest and urban ecological management. It has been proved that traditional methods and data cannot meet such requirements. In this study, a total of 394 reflectance spectra (between 350 and 2500 nm) from foliage branches or canopy of 11 important urban forest broadleaf species were measured in the City of Tam...

Twenty species of oak (Quercus) are known from California. The white oak group is the most diverse, and includes a complex of scrub oak species that are often encountered in chaparral, mixed forest and desert margin habitats. The Protobalanus group (e.g., Quercus chrysolepis) is a unique and distinctive clade of western North American species that appears to be most closely related to the white...

We investigated the competitive response of oak and mountain laurel to prescribed fire on two sites in northeastern Connecticut. After nearly a decade, the competitive position of oak on moderately burned portions of both sites was little better, and in some respects worse, than on adjacent unburned controls. However, on portions of both sites where fire had killed much of the overstory, oak re...