Treesearch

We explored geographic patterns and synchrony of Oregon white oak (Quercus garryana) acorn production over 8 years from Vancouver Island, British Columbia to Medford, Oregon. We divided our data into geographic areas: Puget-Willamette Trough, Columbia Gorge-East Cascades (Eastside) xeric, Eastside mesic, Cascade Mountain foothills, Roseburg, and Medford to compare annual acorn production among areas. Correlogram analysis indicated significant acorn crop correlation throughout the Puget- Willamette Trough, but synchrony was higher over greater distances among stands than among trees....

Strip malls (also known as mini-malls) are a common urban land use, historically promoted by U.S. zoning practices that concentrate retail and commercial development in a narrow band along arterials and major streets. More recently, communities are redeveloping mini-mall zones, expanding landscape plantings as biotechnology, and attempting to create a sense of place. This study assessed public response to urban forest and landscape options. Surveys depicted varied roadside, property-edge treatments. Residents of three major cities in the Pacific Northwest, U.S., were asked to indicate...

This Invited Feature focuses on the U.S. national Fire and Fire Surrogate study (FFS), a multisite multidisciplinary research project that evaluates the ecological consequences of prescribed fire and its mechanical surrogates, treatments that are intended to reduce fire risk and restore resiliency in seasonally dry forests. The primary goal of the FFS study was to measure and compare the effectiveness and ecological consequences of commonly used fuel reduction treatments. The national Fire and Fire Surrogate study is providing answers to many of the important questions that surround the...

Biomass consumption and C02, CO and hydrocarbon gas emissions in an Amazonian forest clearing fire are presented and discussed. The experiment was conducted in the arc of deforestation, near the city of Alta Floresta, state of Mato Grosso, Brazil. The average carbon content of dry biomass was 48 percent and the estimated average moisture content of fresh biomass was 42 percent on wet weight basis. The fresh biomass and the amount of carbon on the ground before burning were estimated as 528 t/ha and 147 t/ha, respectively. The overall biomass consumption for the experiment was estimated as...

The relationship between catchment structure and runoff characteristics is poorly understood. In steep headwater catchments with shallow soils the accumulation of hillslope area (upslope accumulated area [UAA]) is a hypothesized first-order control on the distribution of soil water and groundwater. Hillslope-riparian water table connectivity represents the linkage between the dominant catchment landscape elements (hillslopes and riparian zones) and the channel network. Hydrologic connectivity between hillslope-riparian-stream (RRS) landscape elements is heterogeneous in space and often...

Brief summary of soil, topographic, and climate factors to consider when evaluating sites for possible planting of hardwoods, especially red alder and hybrid poplar.

Successful reforestation requires planted or naturally regenerated seedlings that are well suited to the site. To ensure adapted seedlings, forest managers must be prepared and plan for climate change. Genetic options for adapting to climate change are discussed in the context of both naturally regenerated and planted forests.

Remote sensing provides a broad view of landscapes and can be consistent through time, making it an important tool for monitoring and managing protected areas. An impediment to broader use of remote sensing science for monitoring has been the need for resource managers to understand the specialized capabilities of an ever-expanding array of image sources and analysis techniques. Here, we provide guidelines that will enable land managers to more effectively collaborate with remote sensing scientists to develop and apply remote sensing science to achieve monitoring objectives. We first...

Hydraulic conductance of leaves (Kleaf) typically decreases with increasing water stress. However, the extent to which the decrease in Kleaf is due to xylem cavitation, conduit deformation, or changes in the extra-xylary pathway is unclear, We measured Kleaf concurrently with ultrasonic acoustic emission (UAE) in dehydrating leaves of two vessel-bearing and two tracheid-bearlng species to determine whether declining Kleaf was associated with an accumulation of cavitation events. In addition, images of leaf internal structure were captured using cryo-scanning electron microscopy, which...

In temperate rain forests of western North America, some second-growth forests are managed to promote development of the multidimensional structures observed in old-growth forests. Information about tree architecture from across a range of growing conditions is needed to support this goal. Accordingly, branch and crown dimensions associated with tree age, site index, and stand basal area are reported for 854 Douglas-fir trees, which were harvested from old-growth forests in Washington, Oregon, and northern California in the 1960s. Sample trees ranged from 38 to 647 years old. The average...