Treesearch

Occupancy models are widely used to analyze presence-absence data for a variety of taxa while accounting for observation error (MacKenzie et al. 2002, 2006; Tyre et al. 2003; Royle and Dorazio 2008). Hayes and Monfils (2015) question their use for analyzing avian point count data based on purported violations of model assumptions incurred by avian mobility. Animal mobility is an important consideration, not just for occupancy models, but for a variety of population and habitat models (Boyce 2006, Royle et al. 2009, Manning and Goldberg 2010, Dormann et al. 2013, Renner et al. 2015)....

Drought can have severe impacts on rangeland ecosystems in North America. For the purposes of this chapter, rangelands include natural grasslands, savannas, shrublands, many deserts, tundras, alpine communities, marshes, meadows, and woodlands. Drought impacts vary depending on the severity, frequency, duration, and aerial extent of the drought(s); how the land is managed; and whether plans are in place and implemented to respond to drought. Drought can be simply defined as "a lack of water" characteristic of time, not of place; or it can be defined in a climatic context, as "precipitation...

Snags provide habitat for numerous species of wildlife. Several authors have provided recommendations for snag retention in southwestern mixed-conifer and ponderosa pine (Pinus ponderosa) forests. Most recommendations were presented in terms of minimum snag density and/or size. I summarized the history of recommendations for snag retention in these forest types, and used data from a current study of snag populations (conducted within Coconino and Kaibab National Forests, north-central AZ, USA, 1997 through 2012) to assess congruence between existing snag populations and various recommendati...

The ecological impacts of modern global climate change are detectable in a wide variety of phenomena, ranging from shifts in species ranges to changes in community composition and human disease dynamics. So far, however, little attention has been given to temporal changes in spatial synchrony—the coincident change in abundance or value across the landscape—despite the importance of environmental synchrony as a driver of population trends and the central role of environmental variability in population rescue and extinction. Here we demonstrate that across North America, spatial synchrony of...

Understanding employment trends is important for discerning the economic vitality of U.S. hardwood lumber users. After a period of growth in the 1990s, employment in industries consuming hardwood lumber has declined in the 21st century. The wood household furniture industry has experienced the greatest decline, with North Carolina, Virginia, and California being the states most affected. Nearly all of the decline in employment in the furniture industry can be attributed to increased importation of this product. Millwork and kitchen cabinets are industries associated with home construction....

This study examines the production and efficiency of wildland fire suppression effort. We estimate the effectiveness of suppression resource inputs to produce controlled fire lines that contain large wildland fires using stochastic frontier analysis. Determinants of inefficiency are identified and the effects of these determinants on the daily production of controlled fire line are examined. Results indicate that the use of bulldozers and fire engines increase the production of controlled fire line, while firefighter crews do not tend to contribute to controlled fire line production....

Pondberry (Lindera melissifolia (Walter) Blume) is a deciduous woody shrub in the Lauraceae that is endemic to low-lying forests in seven southeastern states. In the Mississippi Alluvial Valley, pondberry occurs in the understory of bottomland hardwood forests. This rare shrub was listed as an endangered species in 1986. The U.S. Fish and Wildlife Service published a pondberry recovery plan in 1993, establishing objectives for recovery and delisting the species. One action step to delisting pondberry is the development of management practices to recover and conserve the species. The Center...

The US Fish and Wildlife Service is considering the addition of 374 riparian and aquatic species in the southeastern United States to the federal Threated and Endangered Species List. This recommendation is a result of a 2011 petition, which recognized forest operations as having negative effects on 51 percent of the listed species, citing research conducted in the absence of Best Management Practices (BMPs) (Federal Register 76(187):59836-59862). We conducted a literature review to evaluate how BMPs might benefit these species, but found that information specific to these riparian species...

Wecompared nitrogen (N) storage and flux in soils froman ombrotrophic bogwith that of a minerotrophic fen to quantify the differences in N cycling between these two peatlands types in northernMinnesota (USA). Precipitation, atmospheric deposition, and bog and fen outflowswere analyzed for nitrogen species. Upland and peatland soil sampleswere analyzed for N content, and for ambient (DN) and potential (DEA) denitrification rates. Annual atmospheric deposition was: 0.88-3.07 kg NH4+ ha-1 y-1; 1.37-1.42 kg NO3- ha-1 y-1; 2.79-4.69 kg TN ha-1 y-1. Annual N outflows were: bog—0.01-0.04 kg NH4+...

Much like other scientific endeavours, most fire research is conducted either within individual disciplines - fuels, physics, chemistry, ecology, modelling, and so forth - or, at best, across only two or three disciplines. This is primarily because fire scientists have particular areas of expertise and most collaborations are between scientists within that expertise. Although this approach often leads to significant discoveries, the lack of co-located, multi-scale measurements of pre-fire fuels, active fire processes and post-fire effects hinders our ability to tackle fundamental questions...