Treesearch

We evaluated shoot nonstructural carbohydrate (NSC) concentrations, stem wound closure, and radial growth of sugar maple (Acer saccharum Marsh.) and red maple (Acer rubrum L.) trees in a novel ice storm experiment in which five storm treatments (0, 6.4, 12.7, and 19.1 mm of radial ice accretion in 1 year and 12.7 mm of ice in two consecutive years) were applied within a mature northern hardwood forest. We tested for changes in physiology at two levels: (1) associated with plot-level ice treatments and (2) with crown damage classes of individual trees. Few differences in NSC or wound...

Background: Reducing Emissions from Deforestation and forest Degradation (REDD+) is a program established under the United Nations Framework Convention on Climate Change (UNFCCC) to reduce carbon emissions from forests in developing countries. REDD+ uses an incentive-based approach whereby participating countries are paid to reduce forest carbon loss and increase carbon storage. Country-level carbon accounting is challenging, and estimates of uncertainty in emission reductions are increasingly required in REDD+ reports. This requirement is hard to meet if countries lack the necessary...

Trees are exposed to a variety of stressors over their lifetimes. To survive and thrive under diverse conditions, they have evolved a suite of defenses, which confer resistance or tolerance to most biotic and abiotic stressors. Even though disease (or insect pest infestation) is the exception and not the rule, pests and pathogens have had and continue to have a profound impact on the health of forests globally. This is especially true for invasive and/or non-native pests and pathogens and, more recently, for native pests and pathogens whose range or virulence has changed because of climate...

Prior research has indicated lower crime rates in areas with greater tree canopy cover predominantly in the Global North. There are few studies from the Global South, and more specifically in Latin America. Given the high prevalence of crime in Latin American cities, the need to address social and environmental inequalities using nature-based solutions is urgent. This study examines crime and tree canopy cover through a series of spatial analyses for São Paulo city, Brazil, while controlling for potential confounders. We tested six levels of data aggregation that were combined with three...

The American Pika (Ochotona princeps) has been considered a species at risk due to warming temperatures associated with climate change. Many life-history attributes of pikas contribute to the sensitivity of pikas to warming temperatures. Repeated censuses of a marginal (warm, low-elevation) population of pikas at Bodie State Historic Park, California, conducted from 1972 to 2022, are presented to track the population trajectory of pikas for a time period predating recent awareness of global warming to the present day, thus giving a comprehensive portrayal of how American pikas may be...

Around the world, emerging infectious diseases (EIDs) are affecting tree populations and changing forest communities. More widespread and severe in recent decades, these diseases harm native plant populations and the health of commercially available plants used in landscaping, agriculture, and forestry. One of the more extreme examples is chestnut blight, which killed most of the American chestnut trees in North America between 1900 and 1950.

Besides the importance of internal quality, the textural quality properties of the product have a remarkable effect on consumer satisfaction and market price. Mainly, the three-dimensional (3D) modeling technique is applied to evaluate the quality of agricultural products. This study aimed to employ the structure from motion (SFM) method along with the particle film technique to predict the physical features of tomatoes. Reconstructing 3D models of tomatoes is challenging due to their shiny skin. In this study, a new method based on particle films was developed to address this issue. Fifty...

Berkovich nanoindentation was used to characterize viscoelastic and viscoplastic deformations in the semicrystalline polymers, poly(ether ether ketone) (PEEK) and low density polyethylene (LDPE). The quasistatic experiments generated viscoelastic moduli over four decades in frequency and hardness over more than four decades of indentation strain rate. These semicrystalline polymer results augment analogous results previously obtained from the amorphous polymers, poly(methyl methacrylate), polycarbonate, and polystyrene. Although nanoindentation viscoelastic moduli were all systematically...

Background: Ecosystem management, community restoration, and managing for climate resilience have become major priorities of land management in recent decades. For woodlands and savannas (i.e., “open forests”), this transition has meant moving fire-deprived, closed-canopy forests to structures and compositions characteristic of natural communities that are rare today: open-grown, wide-spreading trees, and endemic flora and fauna associated with frequent, low to moderate intensity fires. Open forest restoration is complex; its approach and operational prescriptions are dependent on a...

To compare hardness versus strain rate data from different kinds of indentation creep test can be challenging. It is often difficult to determine whether measured differences in material response along different loading paths, such as constant load creep or load relaxation, are real or merely arise as artifacts from the analysis. We argue that the difficulty lies in how indentation strain rate is defined. For traditional definitions of strain rate, such as εh, which measures the rate of penetration, or εA, which measures the growth of indent area, material response might seem path-dependent...