Treesearch

Disturbance events strongly affect the composition, structure, and function of forest ecosystems; however, existing US land management inventories were not designed to monitor disturbance. To begin addressing this gap, the North American Forest Dynamics (NAFD) project has examined a geographic sample of 50 Landsat satellite image time series to assess trends in forest disturbance across the conterminous United States for 1985-2005. The geographic sample design used a probability-based scheme to encompass major forest types and maximize geographic dispersion. For each sample location...

Fiberboard is a common interior material used both in China and the United States of America. The increase in demand for interior materials has raised concerns regarding combustibility of the materials. The pyrolysis characteristics of fiber, phenolic resin (PF), and nano kaolin-clay (NK) were investigated using thermogravimetry. The fire performances of samples coated with a mixture of NK and PF were determined using a cone calorimeter. The pyrolysis process of fiber included three phases dependent on chemical composition. The initial temperature of PF pyrolysis was about 100 °C and it...

We examined the short term response of herpetofauna to two treatments designed to regenerate oak in upland hardwood forest: (1) shelterwood (30–40% BA retention), and (2) oak-shelterwood (midstory removal by use of herbicide), along with controls. Research was conducted 1 and 2 years post treatment within an oak-hickory forest within the mid-Cumberland Plateau of southern Tennessee. Reptiles and amphibians were captured using drift fences equipped with double-ended funnel traps and pitfall traps. The shelterwood treatment had the least canopy cover and greatest amount of light at the...

This volume perfectly illustrates the truism—"we don't know what it is that we don't know." I have been a landscape ecologist for over 20 years, and have even used expert knowledge many times in my own research. Yet I learned something profoundly new in almost every chapter of this collection of primers and case studies focused on the use of expert knowledge in landscape ecology. The volume is comprised of contributed chapters featuring a nice variety of research questions, ecosystems and approaches, all from a landscape ecology perspective. The quality of the chapters is consistently...

Enzymatic saccharification of cellulose is a key step in conversion of plant biomass to advanced biofuel and chemicals. Many substrate-related factors affect saccharification. Rather than examining the role of each individual factor on overall saccharification efficiency, this study examined how each factor affects the three basic processes of a heterogeneous biochemistry reaction: (1) substrate accessibility to cellulose-the roles of component removal and size reduction by pretreatments, (2) substrate and cellulase reactivity limited by component inhibition, and (3) reaction conditions-sub...

Numerous measures of human influence on the environment exist, but one that is of particular importance is houses as they can impact the environment from species through the landscape level. Furthermore, because the addition of houses represents an important component of landscape change, housing information could be used to assess ecological responses (e.g., decline in wildlife habitat) to that change. Recently developed housing density data represents a potential source of information to assess landscape and habitat change over long periods of time and at broad spatial extents, which is...

Sustainable management of national forests and grasslands within the National Forest System (NFS) often requires managers to make tough decisions under considerable uncertainty, complexity, and potential conflict. Resource decisionmakers must weigh a variety of risks, stressors, and challenges to sustainable management, including climate change, wildland fire, invasive species, insects, pests, diseases, demographic shifts, economic conditions, and changing societal values. The craft of natural resource decisionmaking will demand more adaptive qualities in the future and a more flexible...

There is growing urgency to enhance the sustainability of existing and emerging cities. The science of ecology, especially as it interacts with disciplines in the social sciences and urban design, has contributions to make to the sustainable transformation of urban systems. Not all possible urban transformations may lead toward sustainability. Ecological science helps identify components of resilience that can favor transformations that are more sustainable. To summarize the dynamics and choices involved in sustainable transformations, a "metacity" framework is presented, embracing...

Twenty-three species of gall midges occur exclusively on hackberries in North America north of Mexico. Twenty-one of them belong to the genus Celticecis and form complex, dehiscent galls on leaves and the current year's twigs. Celticecis species are definitely known only from the typical subgenus of Celtis, distributed through much of the Holarctic Region. Nearctic species do not appear to discriminate among hosts within the subgenus but each its individual geographic limits. Galls of most species of Celticecis grow quickly in early spring, but some have a delayed, late summer development.

Forestlands across the world are experiencing increased threats from fire, insect and plant invasions, disease, extreme weather, and drought. Scientists project increases in temperature and changes in rainfall patterns that can make these threats occur more often, with more intensity, and/or for longer durations. Although many of the effects of future changes are negative, natural resource management can help mitigate these impacts. Management strategies informed by the best current science enable natural resource professionals within the Forest Service to better protect the land and...