Treesearch

Group-selection silviculture has many benefcial attributes and has increased in application over the past 30 years. One diffculty with group-selection implementation is the designation of group openings within a stand to achieve a variety of complex management goals. This study presents a new method for utilizing geospatial census stem map data derived from airborne lidar in a heuristic environment to generate and select from treatment solutions that best meet management objectives in an effcient manner. The method successfully generated candidate treatment solutions over two entries that...

Outdoor recreation is increasingly recognized to impact nature and wildlife, yet few studies have examined recreation within large natural landscapes that are critical habitat to some of our most rare and potentially disturbance-sensitive species. Over six winters (2010-2015) and four study areas (> 1.1 million ha) in Idaho,Wyoming, and Montana, we studied the responses of wolverines (Gulo gulo) to backcountry winter recreation. We fit Global Positioning System (GPS) collars to 24 individual wolverines and acquired > 54,000 GPS locations over 39 animal-years during winter (January-April)....

Walnuts (Juglans spp.) are economically important nut and timber species with a worldwide distribution. Using the published Persian walnut genome as a reference for the assembly of short reads from six Juglans species and several interspecific hybrids, we identified simple sequence repeats in 12 Juglans nuclear and organellar genomes. The genome-wide distribution and polymorphisms of nuclear and organellar microsatellites (SSRs) for most Juglans genomes have not been previously studied. We compared the frequency of nuclear SSR motifs and their lengths across Juglans, and identified...

Annually dated tree-rings of 509 live and deadwood limber pine (Pinus flexilis) samples from the semi-arid Wassuk Range, Nevada, yielded a 3996-yr record extending from 1983 BC to AD 2013. Correlations of radial growth with climate were positive for water relations and negative for summer temperatures. Long-term trends of ring-width corresponded to climate variability documented from other proxies, including low growth during the Late Holocene Dry Period and Medieval Climate Anomaly (MCA) and elevated growth during cool, wet periods of the Neoglacial and Little Ice Age. Spline fit of the...

A major task for researchers in the twenty-first century is to predict how climate-mediated stressors such as wildfires may affect biodiversity under climate change. Previous model predictions typically did not address non-stationarity in climate-fire relationships across time and space. In this study, we applied spatially-explicit non-stationary area burned projection models to evaluate recent and future climate-driven trends in area burned across the ranges of three spotted owl subspecies in the western United States. We also used high-severity fire probability models to evaluate the...

Context: Habitat loss and fragmentation are the most pressing threats to biodiversity, yet assessing their impacts across broad landscapes is challenging. Information on habitat suitability is sometimes available in the form of a resource selection function model developed from a different geographical area, but its applicability is unknown until tested. Objectives: We used the Mexican spotted owl as a case study to demonstrate how models developed from different geographic areas affect our predictions for habitat suitability, landscape resistance, and connectivity. We identified the most...

A landscape succession paradigm has shaped much of our understanding about the processes of forest emergence and transformation in the United States. Drawing heavily from theory and method in environmental history, this paradigm has focused attention on the role of landscape-scale shifts in land use and land cover in the production of forests. The geography of cities is patchy, dynamic and heterogeneous, with change and differences occurring at much smaller scales (e.g. Jacobs 1961; Clay 1973) compared to coarse scale of stand replacing successions affecting rural forests (Grove et al....

Background: Historical forests (circa 1799 to 1846) of Indiana were predominantly composed of American beech (25% of all trees) and upland oaks (27% of all trees). I compared historical forest composition, using studies of smaller areas to approximate composition for uncommon species or genera (< 4.5% of all trees) and forest types, to current forest composition and forest types in Indiana. I also compiled published historical density estimates from small studies and estimated current density for the state. Results: Current forests are diverse with an even composition of many eastern...

Occupancy-based surveys are increasingly used to monitor wildlife populations because they can be more cost-effective than abundance surveys and because they may track multiple species, simultaneously. The design of these multi-species occupancy surveys affects statistical power to detect trends in occupancy because individual species vary in resource selection, detection probability, and rarity. We tested for differences in the ability of a large-scale monitoring program to detect changes in single-species occupancy of 13 medium–large mammal species captured on n = 183 cameras systematical...

Old trees (defined here as ≥150 years old) can be rare in many forests because of past timber harvest, uncharacteristically severe wildfires, and - increasingly - climate change. Old trees provide unique structural, ecological, scientific, and aesthetic values missing in forests containing only younger trees. Here we compile crossdated ages from over 10,000 living and dead trees sampled in montane forests of the central Rocky Mountains in Colorado and southern Wyoming, USA, to examine changes in age structure of the oldest trees since Euro-American settlement and to provide guidelines to...