Treesearch

Noxious weeds plague farmers and ranchers, push out native species, and cause both economic and ecological damage. Synthetic herbicides, developed in the 1940s, are often used to control the spread of these plants. By the late 1950s, scientists noticed that some herbicides were no longer effective on certain plant species, even after a typically lethal dose. Since then, scientists have worked to understand the plant traits and management actions that lead to herbicide resistance. This work is especially important as land managers attempt to eradicate plants legally deemed "noxious" and...

En las semanas posteriores al incendio en Cedar Creek en el 2022, se movilizó un equipo de Respuesta de Emergencia en Áreas Quemadas (Interagency Burned Area Emergency Response, BAER) para identificar y mitigar los riesgos para la vida y la seguridad humanas y los recursos hídricos críticos en las comunidades circundantes, incluida Oakridge, Oregón. Durante su evaluación, el equipo de BAER utilizó una guía de campo desarrollada por la Estación de Investigación de Rocky Mountain para elaborar un mapa de la severidad de los suelos quemados e identificar áreas propensas a una erosión más...

Upland oak trees are ecologically, economically, and socially important across the central and eastern United States, but they are at risk of decline from myriad threats. Most of the forestland in this region is held by families and individuals (family forest owners, FFOs), so the future of these oak forests largely depends on the decisions they make about their land. We surveyed 20,000 FFOs and received 1,517 responses to better understand their attitudes towards upland oak forests and management practices that can be used to support oak, specifically harvesting, planting, using herbicides...

Cellulose nanocrystals (CNCs) are considered a prospective packaging material to partially replace petroleum-based plastics attributed to their renewability, sustainability, biodegradability, and desirable attributes including transparency, oxygen, and oil barrier properties. However, neat CNC films are rigid and too brittle to handle or utilize for packaging applications. Hence different additives, including sorbitol, polyvinyl alcohol (PVA), chitin, and κ-carrageenan (CG) were selected to mix with CNCs for packaging film preparation. The influence of additive categories (plasticizer,...

Multilayer films consisting of nanocellulose and nanochitin as oxygen barrier coatings and a conventional petroleum-based moisture barrier plastic as the substrate have been widely studied for food packaging applications. A challenge with enabling recycling of such hybrid multilayer materials is separating the coating from the substrate. In this work, we studied multilayer films consisting of poly(ethylene terephthalate) (PET) as a model substrate with chitin nanowhiskers (ChNWs) and cellulose nanocrystals (CNCs) as bilayer barrier coatings. Dissolution in aqueous media at different pH...

In this study, we perform a comprehensive examination of the ultrasonic dewatering of cellulose nanofibril (CNF) suspensions, with particular emphasis on the role of fines content. The production of CNFs involves mechanical fibrillation which leads to the presence of different percentages of fines (fibrils under 200 μm) in the final product. Although fines have demonstrated mechanical advantages in composite materials, they also increase water retention by the fibrils, leading to increased dewatering time and energy. We selected two distinct CNF samples with 60% and 90% fines, respectively,...

Complex adaptive systems (CASs), from ecosystems to economies, are open systems and inherently dependent on external conditions. While a system can transition from one state to another based on the magnitude of change in external conditions, the rate of change—irrespective of magnitude—may also lead to system state changes due to a phenomenon known as a rate-induced transition (RIT). This study presents a novel framework that captures RITs in CASs through a local model and a network extension where each node contributes to the structural adaptability of others. Our findings reveal how RITs...

Carbon is a building block of life, a central biogeochemical element in the earth system, and an important constituent of Earth’s atmosphere as a greenhouse gas (GhG) that powerfully influences global climate. Human activity has radically altered the global carbon balance in fundamental ways, with severe consequences for the Earth system. Vast quantities of carbon have been emitted as CO2 from oxidation of the primary carbon-containing fuels humans have used over the past two centuries, and from the destruction of natural ecosystems for agriculture, resource extraction, industry, transporta...

Diaphragms are used to transmit lateral loads to the vertical elements (e.g., shear walls) of the lateral force resisting system of a structure. The extent of deflection in diaphragms can determine what mechanism needs to be considered during design for transfer of forces to the vertical elements. Current design specifications do not provide equations that engineers can use to determine the deflections in cantilever Cross-Laminated Timber (CLT) diaphragms. In this paper, the CLT shear wall equation prescribed by 2021 Special Design Provisions for Wind and Seismic (SDPWS) was adapted to get...