Treesearch

Forest biomass reductions in overgrown forests have the potential to provide hydrologic benefits in the form of improved forest health and increased streamflow production in water‐limited systems. Biomass reductions may also alter evaporation. These changes are generated when water that previously would have been transpired or evaporated from the canopy of the removed vegetation is transferred to transpiration of the remaining vegetation, streamflow, and/or non‐canopy evaporation. In this study, we combined a new vegetation‐change water‐balance approach with lumped hydrologic modelling...

United States forestland is an important ecosystem type, land cover, land use, and economic resource that is facing several drivers of change including climatic. Because of its significance, forestland was identified through the National Climate Assessment (NCA) as a key sector and system of concern to be included in a system of climate indicators as part of a sustained assessment effort. Here, we describe 11 informative core indicators of forests and climate change impacts with metrics available or nearly available for use in the NCA efforts. The recommended indicators are based on a...

Lignin, a renewable biopolymer recovered from the chemical processing of woody biomass, has potential to enhance the mechanical properties of epoxy resins with the added benefit of reduced contents of non-renewable petroleum-based polymers. Lignin-based epoxy resins were prepared by employing a carboxylated lignin as a cohardener using a “one-pot” method. The effect of lignin content and preparation method on mechanical properties, apparent morphology, and thermodynamic properties of the resulting epoxy resins were then studied. The results showed that elongation at break increased from...

Warming‐induced mountain pine beetle (Dendroctonus ponderosae; MPB) outbreaks have caused extensive mortality of whitebark pine (Pinus albicaulis; WBP) throughout the species’ range. In the highest mountains where WBP occur, they cross alpine treeline ecotones (ATEs) where growth forms transition from trees to shrub‐like krummholz, some of which survived recent MPB outbreaks. This observation motivated the hypothesis that ATEs are refugia for WBP because krummholz growth forms escape MPB attack and have the potential to produce viable seed. To test this hypothesis, we surveyed WBP mortality...

Owls play important cultural, ecological, and indicator roles throughout the world. Yet owls’ cryptic behavior has led to uncertainties about their basic ecology, including foraging, communication, and functional roles within the community, and potentially hindered the implementation of effective conservation measures. Here we demonstrate the potential for next‐generation GPS tags capable of recording high‐precision, minute‐by‐minute locations paired with other technologies to resolve some of these uncertainties. We combined high‐precision GPS tagging data with infrared (IR) video recorded...

Demographic models enhance understanding of drivers of population growth and inform conservation efforts to prevent population declines and extinction. For species with complex life histories, however, parameterizing demographic models is challenging because some life stages can be difficult to study directly. Integrated population models (IPMs) empower researchers to estimate vital rates for organisms that have cryptic or widely dispersing early life stages by integrating multiple demographic data sources. For a stream‐inhabiting frog (Rana boylii) that is declining through much of its...

Despite a multitude of small catchment studies, we lack a deep understanding of how variations in critical zone architecture lead to variations in hydrologic states and fluxes. This study characterizes hydrologic dynamics of 15 catchments of the U.S. Critical Zone Observatory (CZO) network where we hypothesized that our understanding of subsurface structure would illuminate patterns of hydrologic partitioning. The CZOs collect data sets that characterize the physical, chemical, and biological architecture of the subsurface, while also monitoring hydrologic fluxes such as streamflow,...

Urban forested natural areas are valuable ecological and social resources, but long-term sustainability of these habitats is challenged by environmental and social factors associated with urban ecosystems. Advances in city-scale assessments of urban forests have increased the resolution of forest community types and conditions, allowing for improved understanding of ecological function, such as natural regeneration, in these urban habitats. By applying metrics of tree regeneration that are commonly used for the management of rural forests, urban ecologists can test the potential for...

Emerald ash borer (EAB), (Agrilus planipennis Fairmaire), first identified in 2002 in southeast Michigan, has caused catastrophic ash (Fraxinus spp.) mortality in forests within the core of the invasion and has spread to 35 states and five Canadian provinces. Little is known about persistence and densities of EAB populations in post-invasion sites after most ash trees have died. We monitored EAB populations from 2014 to 2016 using double decker (DD) traps set in the midst of white ash (F. americana) trees in 30 post-invasion sites in southeast and south-central Michigan. Two DD traps were...

Uncertainty information associated with urban forest models are beneficial for model transparency, model development, effective communication of model output, and decision-making. However, compared with the extensive studies based on the applications of urban forest models, little attention has been paid to the uncertainty of the output from these models. In this study, bootstrap and Monte Carlo simulation were employed to explore the uncertainty of i-Tree Eco. We assess the uncertainties associated with input data, sampling methods and models throughout the processes of urban forest...