Treesearch

This article describes the development of a methodology for scaling observations of changes in tropical forest cover to large areas at high temporal frequency from coarse-resolution satellite imagery. The approach for estimating proportional forest cover change as a continuous variable is based on a regression model that relates multispectral, multitemporal Moderate Resolution Imaging Spectroradiometer (MODIS) data, transformed to optimize the spectral detection of vegetation changes, to reference change data sets derived from a Landsat data record for a study site in Central America. A...

The Columbia River today is a great "organic machine" (White 1995) that dominates the economy of the Pacific Northwest. Even though natural attributes remain—for example, salmon production in Washington State's Hanford Reach, the only unimpounded reach of the mainstem Columbia River—the Columbia and Snake River mainstems are dominated by technological operations supporting the region's economy (e.g., hydropower production, irrigation systems, flood control, commercial barging). Operation of the river via the hydropower system is driven largely by economic considerations of water...

Selected tree height and diameter functions were evaluated for their predictive abilities for major tree species of southwest Oregon. The equations included tree diameter alone, or diameter plus alternative measures of stand density and relative position. Two of the base equations were asymptotic functions, and two were exponential functional forms. The inclusion of the crown competition factor in larger trees and basal area, which indicates the relative position of a tree and stand density, into the base height-diameter equations increased the accuracy of prediction for all species. On...

Salmon carcass addition to streams is expected to increase stream productivity at multiple trophic levels. This study examined stream nutrient (nitrogen, phosphorus, and carbon), epilithic biofilm (ash-free dry mass and chlorophyll a), leaf-litter decomposition, and macroinvertebrate (density and biomass) responses to carcass addition in three headwater streams of southwestern Washington State, USA. We used stable isotopes (δ13C and δ15N) to trace incorporation of salmon-derived (SD) nutrients into stream food webs. SD nutrients were assimilated by biofilm, benthic insects (Perlidae and...

Cost of private timber management practices in the United States are identified, and their relationship to timber production in general is highlighted. Costs across timber-producing regions and forest types are identified by forest type and timber management practices historically applied in each region. This includes cost estimates for activities such as forest establishment practices such as reforestation and afforestation on crop and pastureland. Establishment costs for reforestation in the Southern United States are less than in other regions, although regional differences in establishm...

In March 23-25, 2005, an international symposium on red alder was held at the University of Washington Center for Urban Horticulture in Seattle, WA. The symposium was entitled "Red alder: A State of Knowledge" and brought together regional experts to critically examine the economic, ecological and social values of red alder. The primary goal of the symposium was to discuss new advances in the understanding of red alder biology and silviculture, changing market and nonmarket values, and the current regulatory climate for management of alder. This proceedings includes 14 papers based on oral...

Prescribed burning is a management tool used to reduce fuel loads in western interior forests. Following a burn, managers need the ability to predict the mortality of individual trees based on easily observed characteristics. A study was established in six stands of mixed-age ponderosa pine (Pinus ponderosa Dougl. ex Laws.) with scattered western junipers at the south end of the Blue Mountains near Burns, Oregon, USA. Stands were thinned in either 1994 or 1995. Three treatments, a fall burn, a spring burn, and an unburned control, were randomly assigned to 12-ha experimental units within...

Although critical to monitoring forest ecosystems, inventories are expensive. This paper presents a generalizable method for using an integer programming model to examine tradeoffs between cost and estimation error for alternative measurement strategies in forest inventories. The method is applied to an example problem of choosing alternative height-modeling strategies for 1,389 plots inventoried by field crews traveling within an 82.5- by 106-ha region of the west coast of North America during one field season. In the first part of the application, nonlinear regional height models were...

Predicted changes in the global climate are likely to cause large shifts in the geographic ranges of many plant and animal species. To date, predictions of future range shifts have relied on a variety of modeling approaches with different levels of model accuracy. Using a common data set, we investigated the potential implications of alternative modeling approaches for conclusions about future range shifts and extinctions. Our common data set entailed the current ranges of 100 randomly selected mammal species found in the western hemisphere. Using these range maps, we compared six methods...

Several plant functional traits were studied in five dominant woody savanna species in a Brazilian savanna to determine whether removal of nutrient limitations has an effect on carbon allocation, water relations, and hydraulic architecture. Four treatments consisting of a control, and nitrogen (N), phosphorus (P), and N plus P additions were maintained for 5 years. Nitrogen fertilization significantly altered several components of hydraulic architecture. In addition, long-term N and N plus P fertilization caused midday leaf water potential to decline significantly by a mean of 0.6 MPa...