Treesearch

The American Society of Testing and Materials (ASTM), D1990 details standard practices for establishing and maintaining design values for dimension lumber. Included in this standard are statistical methods for detecting changes in dimension lumber properties over time. A characteristic (or design) value, also known as the allowable property, is published for each lumber property, and this value must be updated whenever changes in the resource warrant. Currently ASTM D1990 calls for the use of the Wilcoxon Rank Sum test (also known as the Mann-Whitney test) to detect changes in these...

To update our knowledge about the logging sector in Minnesota and Wisconsin, coordinated mail surveys were conducted during the spring of 2022. The surveys collected data on harvest systems, production volumes, profitability, production capacity, business demographics, capital investment, trucking, stumpage sources, timber products harvested, emerging issues, and more. The average age of logging business owners and their equipment is trending older. Harvest production is trending downward. Stumpage sources are trending away from public lands and relying more on private lands. Delivery is...

Prolonged inundations are altering coastal forest ecosystems of the southeastern US, causing extensive tree die-offs and the development of ghost forests. This hydrological stressor also alters carbon fluxes, threatening the stability of coastal carbon sinks. This study was conducted to investigate the interactions between hydrological drivers and ecosystem responses by analyzing daily eddy covariance flux data from a wetland forest in North Carolina, USA, spanning 2009–2019. We analyzed temporal patterns of net ecosystem exchange (NEE), gross primary productivity (GPP), and ecosystem...

The biogeography of irruptive insect herbivores is determined by host availability and climate conditions. As such, outbreak distributions are sensitive to climatic change, especially across large latitudinal gradients. Here, we investigate the outbreak distributions of two understudied defoliators, hemlock sawfly Neodiprion tsugae (Hymenoptera) and western blackheaded budworm Acleris gloverana (Lepidoptera), that have both recently impacted the greatest land area recorded across the Pacific coastal temperate rainforest since the establishment of aerial survey programs. We compiled...

Increasing the equitable distribution of tree canopy is a priority for many cities, and tree canopy change studies are needed to inform natural resource managers on how and for whom canopy is changing. This study examines relationships between tree canopy change, socioeconomic/demographic characteristics, and land use at the block group and county scales, in Cook County, Illinois from 2010 to 2017. At the block group level, spatial Random Forest Regression models the nonlinear relationships between six canopy metrics and socioeconomic, demographic, and land use predictors. We also tabulated...

We document the characteristics of infrasound from a compact (<3-m burn diameter) wood pile fire using arrays located at 50 and 600 m. Infrasound from our controlled burn is present throughout the entire near-infrasound range (1–20 Hz), but its peak infrasound energy trends from 1.3 to 1 Hz over an hour correlating with a transition from relatively tall and narrow flame to a broader pile of coals with shorter flame. Observed infrasound frequencies correlate with flame flickering – quantified through spectral analysis of video – suggesting that flame and gas pulsing is the mechanism for the...

Background. Pyrogenic organic matter (PyOM) represents a relatively persistent component of soil carbon stocks. Although subsequent fires have the potential to combust or alter preexisting PyOM stocks, simulating soil heating faces important methodological constraints. In particular, methods for estimating the effects of subsequent fire on preexisting PyOM in soil have important limitations. Aims. We aimed to design a laboratory method to effectively simulate soil heating from above, to investigate the impacts of subsequent fires on PyOM at different soil depths while addressing key...

Creation of small canopy gaps around understory eastern hemlocks (Tsuga canadensis (L.) Carrière) can increase resilience to hemlock woolly adelgid (Adelges tsugae Annand), an invasive insect pest in eastern North America. In this study, the diversity and community composition of bees were quantified by monitoring pan traps in canopy gaps (mean size 0.06 ha, created 2.5—3 yrs earlier) and paired control plots (mature, intact forest) in western North Carolina and Virginia. Mean bee richness and abundance were significantly greater in silvicultural gaps. There were significant compositional...

The oxygen evolution reaction (OER) plays a central role as an anode in electrocatalytic processes such as energy conversion and storage and the generation of molecular oxygen from the electrolysis of water. Currently, precious metal oxides such as IrO2 and RuO2 are recognized as reference OER electrocatalysts with reasonably high activity; however, their widespread use in practical devices has been severely hindered by their high cost and scarcity. It is essential to design alternative OER electrocatalysts made of low-cost and abundant earth elements with significant activity and robustnes...

Changing climate conditions, wildfires, and tree harvests could affect the area of mature and old-growth forests in the United States. We used a stochastic modeling system to project future areal extents of mature and old-growth forests on National Forest System (NFS) and Bureau of Land Management (BLM) land across the conterminous United States, and to assess threats to these forests under a variety of socioeconomic and climate futures, to 2070. The area of old-growth forest is expected to increase 19-27% on NFS and BLM lands while mature forest trends (0.8% decrease to 2.5% increase)...