Treesearch

Carbon stored in harvested wood products (HWPs) can affect national greenhouse gas (GHG) inventories,n which the production and end use of HWPs play a key role. The Intergovernmental Panel on Climate Change (IPCC) provides guidance on HWP carbon accounting, which is sensitive to future developments of socioeconomic factors including population, income, and trade. We estimated the carbon stored within HWPs from 1961 to 2065 for 180 countries following IPCC carbon-accounting guidelines, consistent with Food and Agriculture Organization of the United Nations (FAOSTAT) historical data and...

Limber pine in the Great Basin responds to climate change in a diversity of ways, as shown by studies of current and paleo-historic forests. Expected movements of limber pine up in elevation with warming climates are only one of several other -- and unexpected -- responses. The latter include shifts out from mid-elevation forests into sage-steppe shrublands following disruption of local inversions; shifts down in elevation into low, north-facing ravines; and shifts in slope aspect. Climate refugia locations are proposed and researchers are urged to consider non-traditional responses of...

Individual tree growth and mortality drive forest stand dynamics and are universally important metrics of tree success. Studying factors that affect growth and mortality is particularly challenging in mixed-species, unevenaged systems due to their defining heterogeneity and strong temporal and spatial variability. The goal of this study was to determine the relative importance of individual tree attributes (i.e., species, size, neighborhood crowding, crown position) and environmental characteristics (i.e., soil moisture) in driving tree growth and survival in an uneven-aged, mixed species...

Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are the greenhouse gases largely responsible for anthropogenic climate change. Natural plant and microbial metabolic processes play a major role in the global atmospheric budget of each. We have been studying ecosystem-atmosphere trace gas exchange at a sub-boreal forest in the northeastern United States for over two decades. Historically our emphasis was on turbulent fluxes of CO2 and water vapor. In 2012 we embarked on an expanded campaign to also measure CH4 and N2O. Here we present continuous tower-based measurements of the...

Clifford A. Myers conceived the ponderosa pine growing stock levels (GSL) study in 1961 and completed installation of the study in 1963 in western South Dakota on the Black Hills Experimental Forest (BHEF). The GSL concept was intended to help plan, implement, and illustrate tree thinning strategies (from below) in even-aged stands. A GSL is the suggested tree density (i.e., trees and basal area per acre) based on d.b.h. that can be tended to produce a desired basal area per acre (e.g., 80, 100, 120 square feet) when the mean d.b.h. is 10 inches. Plots representing GSLs 20, 40, 60, 80,...

Old-growth coniferous forests of the Pacific Northwest are among the most productive temperate ecosystems and have the capacity to store large amounts of carbon for multiple centuries. To date, there are considerable gaps in modeling ecosystem fluxes and their responses to physiological constraints in these old-growth forests. These model shortcomings limit our ability to understand and project how the old-growth forests of the Pacific Northwest will respond to global climate change. This study applies the cohort-based Ecosystem Demography Model 2 (ED2) to the Wind River Experimental...

This assessment was conducted to provide information on the current conditions of riparian, wetland, and groundwater-dependent ecosystems in reference to their natural range of variation on the Salmon-Challis National Forest during forest plan revision. We used peer-reviewed literature, data from the Forest and other partners, and site visits to evaluate the status of eight key ecosystem characteristics: (1) distribution and connectivity of riparian ecosystems, (2) distribution of groundwater-dependent ecosystems, (3) surface water and groundwater fluctuations, (4) water quality, (5)...

The common assumption of risk neutrality in forest decision making is generally inadequate because the stakeholderstend to be averse to fluctuations in the return criteria. In Markov decision processes (MDPs) of forest management, risk aversionand standard mean-variance analysis can be readily dealt with if the criteria are undiscounted expected values. However, withdiscounted criteria such as the fundamental net present value of financial returns, the classic mean-variance optimization isnumerically intractable. In lieu of this, this paper (i) presents a linear-programming method to...

Wildland fire and ecological researchers use empirical and semi-empirical modeling systems to assess fire behavior and danger. This technical note describes the firebehavioR package, a porting of two fire behavior modeling systems, Crown Fire Initiation and Spread and a Rothermel-based framework, to the R programming language. We also highlight supporting data objects and functions to predict inputs required for fire behavior estimation. Last, this package contains functions for fifteen indices to express fire danger using weather and/or fuels observations. Specific advantages of predicting...

Before the advent of intensive forest management and fire suppression, western North American forests exhibited a naturally occurring resistance and resilience to wildfires and other disturbances. Resilience, which encompasses resistance, reflects the amount of disruption an ecosystem can withstand before its structure or organization qualitatively shift to a different basin of attraction. In fire-maintained forests, resilience to disturbance events arose primarily from vegetation pattern-disturbance process interactions at several levels of organization. Using evidence from 15 ecoregions,...