Treesearch

The reciprocal relationships between ecological process and landscape pattern are fundamental to landscape ecology. Landscape ecologists traditionally use raster maps portraying classified features such as land use or land cover categories, and metrics suggested by the patch-corridor-matrix conceptual model of pattern. Less attention has been given to the landscape gradient conceptual model and raster maps portraying numeric features such as greenness or percent vegetation cover. We introduce the open-source tool GraySpatCon to calculate and map a variety of landscape pattern metrics from...

The USDA Forest Service (Forest Service)’s historical documents collection at the National Archives includes many high-quality digital public domain photographs of foresters, stand conditions, and forest management practices, as well as a number of other subjects. These images offer researchers and managers numerous opportunities to study the American past and thus better address contemporary forest and forestry issues. To demonstrate this, the following pictures of historical longleaf pine (Pinus palustris) woodlands provide a reconsideration of the concept of old-growth forests and...

Predictions as to the quantity of lignocellulosic biomass (LCB) available vary considerably. Estimates range from at least 4 billion to as much as 170 billion metric tons per year worldwide (Klass, 1998; Rowell, 2007). Estimates of total quantity of woody biomass available range from at least 1.75 to 75 billion metric tons per year worldwide ( ~43% of total LCB) (Klass, 1998; Rowell, 2007). In the US, the forest-based biomass supply physically available in 2011 was estimated to be ~45 million dry tonnes per year depending on market economics with a feasible increase to as much as 225...

Woody biomass as a renewable resource for chemicals, materials, and energy has garnered significant attention to replace fossil-carbon sources. However, in carbohydrate-based biorefineries, the recalcitrance of wood warrants a pretreatment prior to further processing by enzymatic hydrolysis (EH) and fermentation. Various processes or a combination thereof, including but not limited to, low pH (mild and strong acid pretreatments), neutral pH (autohydrolysis includes hydrothermal and steam explosion pretreatments), high pH (mild and strong alkali pretreatments), organic solvents, ionic...

While there have been a host of studies investigating the COVID-19 pandemic’s influence on outdoor recreation, few have investigated the socio-demographic composition and motivations of visitors who increased their outdoor recreation during this period and if these users will continue recreating at the same level as the pandemic wanes. This study surveyed visitors to the Nantahala and Pisgah National Forests (NPNF) within the US state of North Carolina to identify if rising outdoor recreation participation is solely a result of the pandemic or more indicative of a renaissance. Demographic...

Mass timber buildings are increasing in popularity as the building industry aims to use more sustainable construction materials. A lateral force resisting system with a mass timber frame and a timber buckling restrained brace (TBRB) is presented as a possible solution to allow the expanded use of mass timber in buildings located in cities with high risk of natural hazards such as earthquakes and hurricanes. A series of nine quasi-static cyclic tests was completed to study the performance of the TBRB frame as well as the elastic performance of the bare mass timber frame. The variables...

Wildfire risks to homes are increasing, especially in the wildland-urban interface (WUI), where wildland vegetation and houses are in close proximity. Notably, we found that more houses are exposed to and destroyed by grassland and shrubland fires than by forest fires in the United States. Destruction was more likely in forest fires, but they burned less WUI. The number of houses within wildfire perimeters has doubled since the 1990s because of both housing growth (47% of additionally exposed houses) and more burned area (53%). Most exposed houses were in the WUI, which grew substantially...

The phaseout of methyl bromide (MB) fumigation creates an urgent need for an alternative phytosanitary treatment tolimit the risk of international spread of the oak wilt fungus, Bretziella fagacearum. Fumigation with ethanedinitrile (EDN) isconsidered a potential alternative to MB fumigation to eradicate wood-inhabiting pests and pathogens. We evaluated theefficacy of EDN fumigation by comparing the rate of B. fagacearum isolation before and after fumigation of red oak(Quercus rubra or Quercus ellipsoidalis) log sections from oak wilt–affected trees. Logs (range 15.2 to 98.0 cm long;diameter...

The summer of 2023 is a notable time for water-resource management in the western United States: Glen Canyon Dam, on the Colorado River, turns 60 years old while the largest dam-removal project in history is beginning on the Klamath River. This commentary discusses these events in the context of a changing paradigm for dam and reservoir management in this region. Since the era of large dam building began to wane six decades ago, new challenges have arisen for dam and reservoir management owing to climate change, population increase, reservoir sedimentation, declining safety of aging dams,...