Treesearch

The magnitude of sediment yield following forest timber harvest is controlled by increases in both sediment supply and streamflow. Since the relation between sediment transport and streamflow typically follows a power law, small increases in streamflow may translate into large increases in sediment transport. Interpreting the geomorphic effects of streamflow increases is confounded by the fact that timber harvest influences both the hydrologic regime and sediment supply of a watershed simultaneously, making it difficult to isolate the streamflow effect alone. Here we report on a novel...

Our knowledge of the root system architecture of trees is still incomplete, especially concerning how biomass partitioning is regulated to achieve an optimal, but often unequal, distribution of resources. In addition, our comprehension of root system architecture development as a result of the adaptation process is limited because most studies lack a temporal approach. To add to our understanding, we excavated 32-year-old Pinus ponderosa trees from a steep, forested site in northern Idaho USA. The root systems were discretized by a low magnetic field digitizer and along with AMAPmod...

Biological soil crusts (BSCs) consist of a diverse and highly integrated community of organisms that effectively colonize and collectively stabilize soil surfaces. BSCs vary in terms of soil chemistry and texture as well as the environmental parameters that combine to support unique combinations of organisms - including cyanobacteria dominated, lichen-dominated, and bryophyte-dominated crusts. The list of organismal groups thatmake up BSC communities in various and unique combinations include - free living, lichenized, and mycorrhizal fungi, chemoheterotrophic bacteria, cyanobacteria,...

The objective of this study was to determine the feasibility of using a transverse free vibration testing method to nondestructively evaluate the bending stiffness and strength of full-size (1220 x 2440 mm) wood composite panels (WCPs). Based on the principle of transverse free vibration of a thin plate, the dynamic modulus of elasticity (MOE) of a full-size WCP supported on two nodal-lines was derived using the Rayleigh method. Transverse free vibration test was conducted on 54 full-size medium density fiberboard (MDF) panels and 36 full-size particleboard (PB) panels under a two-nodal-lin...

The objective of this study was to explore the potential of an acoustic impact test as a nondestructive evaluation procedure to assess the soundness of hardwood logs in terms of internal decay, void, and defect ratio. Fifteen logs of four hardwood species (black cherry, white oak, red oak, and cottonwood) were obtained and subjected to acoustic impact testing. The logs were subsequently dissected for visual examination and physical mapping of the internal defects. The acoustic response signals were analyzed to derive acoustic velocity (through FFT), time centroid (through moment analysis),...

This Research Note describes the rationale for and design of a XyloScope, a digital imaging system for viewing and recording macroscopic images of wood for a XyloTron machine-vision wood identification system, and provides a bill of materials and the associated technical drawings of its components.

The sun bathes the earth in waves of radiated energy. The waves of radiation occur along the electromagnetic spectrum that includes microwaves, radio waves, visible light, and infrared heat. The visible portion of that spectrum is the rainbow formed by sunlight passing through a prism. Solar energy is increasingly used to power our homes, offices, and businesses. Trees and other green plants have been using solar energy for many millions of years. Plants use that radiant energy to make and break chemical bonds that provide the energy needed for growth and survival. Much of the solar...

Aim: Establishments of non‐native forest pests (insects and pathogens) continue to increase worldwide with growing numbers of introductions and changes in invasion pathways. Quantifying spatio‐temporal patterns in establishment locations and subsequent invasion dynamics can provide insight into the underlying mechanisms driving invasions and assist biosecurity agencies with prioritizing areas for proactive surveillance and management. Location: United States of America. Time period: 1794–2018. Major taxa studied: Insecta, plant pathogens. Methods: Using locations of first discovery and...

Urban trees provide numerous benefits to society, but upon removal, this resource is underutilized and often considered a waste product to be discarded. However, urban trees have a potential to be utilized for various products, create jobs and an income stream for cities. The latest data on urban forests in the United States were used to estimate the potential annual value that could be derived from urban tree waste. Assuming a mortality rate of 2%, annual urban woody biomass loss in the U.S. equates to about 46 million tonnes of fresh-weight merchantable wood or 7.2 billion board feet of...

Residential land is expanding in the United States, and lawn now covers more area than the country’s leading irrigated crop by area. Given that lawns are widespread across diverse climatic regions and there is rising concern about the environmental impacts associated with their management, there is a clear need to understand the geographic variation, drivers, and outcomes of common yard care practices. We hypothesized that 1) income, age, and the number of neighbors known by name will be positively associated with the odds of having irrigated, fertilized, or applied pesticides in the last...