Treesearch

Urban green spaces have previously been linked to reduction in crime and improvements in neighborhood environments. This study considered if the Care-A-Lot (CAL) program in Baltimore City, which incentivizes local community groups to maintain and green vacant lots, reduces violent and property crime. Compared to a 2016–2017 baseline, city block groups with CAL programs saw a significantly larger decrease in crime compared to matched block groups with no CAL programs both in 2018 and 2019. These results were found to be robust through a series of sensitivity analyses and add to the literatur...

This study investigated carbonate pre-treatment of wood followed by densification for producing advanced wood structural materials. Poplar wood blocks of 100 mm long and 20 mm wide with thickness of 10 mm were treated with sodium carbonate with and without sulfide at different carbonate loadings at 150 ºC for 30 min. Carbonate effectively removed lignin and hemicelluloses which facilitated subsequent wood densification for improving wood mechanical properties. Comparing with wood pre-treatment using sodium hydroxide, carbonate pretreatment improved wood yield but achieved similar level of...

Agricultural communities and crop production are negatively impacted by invasive species, with the effects of pathogenic fungi, parasitic insects and weedy plants being well studied. Mammals and birds are also recognized as impacting crops, but reptiles, such as non-native green iguanas (Iguana iguana), are typically not considered agricultural pests. Research on non-native green iguanas has largely focused on the lizard’s interactions with native species with little attention given to its impact in the agricultural landscape. We conducted semi-structured interviews with farmers from 20...

Invasive predators can have detrimental impacts on native species and biological communities through direct consumptive effects and indirect effects on trophic interactions, yet these relations are often poorly understood through the initial stages of predator expansion. Leveraging early, lethal collection efforts to study invasive barred owls (Strixvaria) at the leading edge of their range expansion in northeastern California, we conducted DNA metabarcoding of intestinal samples to assess the diet of this invasive predator. Through the development of customized primers and this novel...

Today, more than one-quarter of forests in the northeastern and north-central United States are characterized as mixedwoods–a mixture of hardwoods, like oak (Quercus) and maple (Acer), and softwoods, like pine (Pinus) and hemlock (Tsuga), with neither type making up more than 80 percent of forest composition. These temperate mixedwood forests spread across nearly 47 million acres in the United States, from North Dakota to Maine and Kansas to Maryland. Yet despite their prevalence, there is much to be learned about temperate mixedwood forests. A group of Northern Research Station (NRS)...

It is hard to imagine the vast expanse of the Great Lakes being anything but pristine, yet trouble roils just beneath the surface. The Great Lakes contain roughly 90 percent of the surface freshwater supply in the United States - and 20 percent of the world's freshwater supply. In recent years, increases in the use of electronics, pharmaceuticals, and personal care products has led to an increase in the pollutants that are pumped into the environment every day. Left unchecked, these pollutants can dramatically alter the future of the Great Lakes. Northern Research Station scientists and...

For the last century black cherry (Prunus serotina) has comprised a significant portion of the tree canopy across the Allegheny National Forest. But black cherry's rise to prominence has a complicated history. Following unsustainable timber harvesting in the early 20th century, clearcut forests encouraged pioneer species such as black cherry to thrive. Industrialization later increased the amount of nitrate present in the air, and the new environmental conditions further enhanced the dominance of this nitrogen-demanding species. For years, the timber industry benefited from an abundance of...

Since the late 1920s, the Forest Service has been congressionally mandated to collect, analyze, and report information on the status and trends of America's forests. This includes a suite of measurements on trees (live and dead) and other forest vegetation. Over time, this ongoing effort has evolved into the Forest Inventory and Analysis program. Today, FIA field crews routinely collect a core set of variables within plots across the country, on both public and private lands.

Evaluating genetic diversity in walnut (Juglans regia L.) populations is a rapid approach used by walnut breeding programs to distinguish superior genotypes. The present study was conducted on the walnut population of Hamedan Province, one of the richest and most genetically diverse regions in Iran, during 2018–2019. After the initial screening, 47 genotypes were selected for further evaluation of pomological and phenological traits based on International Plant Genetic Resources Institute (IPGRI) descriptors. Nut and kernel weights among the selected genotypes ranged from 7.15 to 21.05 g...

Signatories to the United Nations Framework Convention on Climate Change (UNFCCC) are required to annually report economy-wide greenhouse gas emissions and removals, including the forest sector. National forest inventory (NFI) is considered the main source of data for reporting forest carbon stocks and changes to UNFCCC. However, NFI samples are often collected asynchronously across regions in intervals of 5–10 years or sub-sampled annually, both introducing uncertainties in estimating annual carbon stock changes by missing a wide range of forest disturbance and recovery processes. Here,...