In 2010, a collaborative project was started to determine the distribution of Armillaria solidipes (= A. ostoyae) in Arizona. The methods and preliminary accomplishments of the 2010 and 2011 (ongoing) field surveys/collections are summarized. During the next phase of this project, surveys will be completed and remaining Armillaria isolates will be identified using DNA-based methods. In addition, a preliminary prediction map based on 25 locations positive for A. solidipes is presented. Sites positive for A. solidipes are associated with climate data to predict the potential current distribution (and disease activity) of A. solidipes within the region. Data from this region can be added to global A. solidipes datasets that will help develop bioclimatic models for predicting the future distribution and disease activity of Armillaria solidipes under various climate-change scenarios.
Rapid climate change over the coming century will impact suitable habitat for many tree species. In response to these changes in climate, areas that become unsuitable will see higher mortality and lower growth and recruitment. Therefore, early detection of demographic trends is critical for effective forest management. Recent 10-year remeasurement data from the United States (US) Department of Agriculture (USDA) Forest Service’s Forest Inventory and Analysis (FIA) Program’s national annual inventory of forest land provides an ideal data set for analyzing such trends over large areas. However, failure to distinguish between areas of future habitat contraction and expansion or persistence when estimating demographic trends may mask species’ shifts. We used remeasurement data to compare observed tree demographic rates with projected impacts of climate change for five important tree species in the Pacific Northwest. Projected impacts were based on spatial-Bayesian hierarchical models of species distributions, which were used to project areas where habitat would persist (remain climatically suitable), expand (become suitable), or contract (become unsuitable) under four future climate scenarios for the 2080s. We compared estimates of mortality and net-growth between these areas of shifting suitability and a naïve division of habitat based on elevation and latitude. Within these regions, we assessed the sustainability of mortality and determined that observational data suggest that climate change impacts were already being felt in some areas by some species. While there is an extensive literature on bioclimatic species distribution models, this work demonstrates they can be adapted to the practical problem of detecting early climate-related trends using national forest inventory data. Of the species examined, California black oak (Quercus kelloggii) had the most notable instances of observed data suggesting population declines in the core of its current range.
Fire regimes in North American forests are diverse and modern fire records are often too short to capture important patterns, trends, feedbacks, and drivers of variability. Tree-ring fire scars provide valuable perspectives on fire regimes, including centuries-long records of fire year, season, frequency, severity, and size. Here, we introduce the newly compiled North American tree-ring fire-scar network (NAFSN), which contains 2562 sites, > 37,000 fire-scarred trees, and covers large parts of North America. We investigate the NAFSN in terms of geography, sample depth, vegetation, topography, climate, and human land use. Fire scars are found in most ecoregions, from boreal forests in northern Alaska and Canada to subtropical forests in southern Florida and Mexico. The network includes 91 tree species, but is dominated by gymnosperms in the genus Pinus. Fire scars are found from sea level to > 4000-m elevation and across a range of topographic settings that vary by ecoregion. Multiple regions are densely sampled (e.g., > 1000 fire-scarred trees), enabling new spatial analyses such as reconstructions of area burned. To demonstrate the potential of the network, we compared the climate space of the NAFSN to those of modern fires and forests; the NAFSN spans a climate space largely representative of the forested areas in North America, with notable gaps in warmer tropical climates. Modern fires are burning in similar climate spaces as historical fires, but disproportionately in warmer regions compared to the historical record, possibly related to under-sampling of warm subtropical forests or supporting observations of changing fire regimes. The historical influence of Indigenous and non-Indigenous human land use on fire regimes varies in space and time. A 20th century fire deficit associated with human activities is evident in many regions, yet fire regimes characterized by frequent surface fires are still active in some areas (e.g., Mexico and the southeastern United States). These analyses provide a foundation and framework for future studies using the hundreds of thousands of annually- to sub-annually-resolved tree-ring records of fire spanning centuries, which will further advance our understanding of the interactions among fire, climate, topography, vegetation, and humans across North America.
For over 35 years, the Starkey project has conducted policy-shaping research on deer and elk.
With its game-proof fence and controlled access, the Starkey Experimental Forest and Range is truly a one-of-a-kind research facility. Combined with automated traffic counters, tractable elk that helped break new ground in elk nutrition, decades of telemetry data, and animal handling facilities and you have a world-class resource and research program referred to as The Starkey Project. A broad spectrum of federal, state, private, Tribal and university partners have collaborated, leading to widespread acceptance and use of results to tackle national issues in resource management. But key to Starkey Project success is the 30-plus year collaboration and co-leadership between the USFS Pacific Northwest Research Station (PNW) and Oregon Department of Fish and Wildlife (ODFW). How has this partnership, and the Project, been so successful? From the get-go, both agencies worked together to develop the facility, its technologies, and research agenda, while leveraging funding and equipment. Both PNW and ODFW support a full-time Starkey Project Leader, with scant turnover through the years. Jack Ward Thomas, Starkey Project Leader for PNW in the 1980s and early 90s, was instrumental in getting the fencing and supporting technologies established, working closely with Donavin Leckenby, Project leader for ODFW. Project staff have always been co-located to ensure the work remains tightly integrated. This long collaboration has been one of the closest and most successful research partnerships that we know of between federal and state agencies. Research results have been widely adopted for managing forests and rangelands of western North America.