Treesearch

Now over twenty years into the 21st century, it is suggested that we are entering a new era of wilderness visitor use management (VUM). Yet, we lack a recent review of the literature assessing the latest research trends to advance wilderness VUM in a meaningful way. Accordingly, this research serves as both a review of the last twenty years of U.S. wilderness VUM research and a launching point into the next era. Our assessment adds to several previous benchmarks that demonstrate the progress of wilderness VUM research. This review evaluates trends in methodologies and themes of inquiry...

Wildfires are increasing in scale and impact on the landscape, altering large amounts of wildlife habitat and forest ecosystems. The reduction of fuels through forest management is considered a primary way to reduce the extent and severity of wildfires before they occur but may lead to a decrease in tree density prohibitive of some species’ habitat. Alternatively, management actions undertaken after a fire may speed the trajectory of burned areas back into quality habitat but may also impede this development if the wrong type of treatment is undertaken. Thus, information on how different...

Precipitation is a key driver of primary production worldwide, but primary production does not always track year-to-year variation in precipitation linearly. Instead, plant responses to changes in precipitation may exhibit time lags, or legacies of past precipitation. Legacies can be driven by multiple mechanisms, including persistent changes in plant physiological and morphological traits and changes to the physical environment, such as plant access to soil water. We used three precipitation manipulation experiments in central Texas, USA to evaluate the magnitude, duration, and potential...

Plants demonstrate a broad range of responses to environmental shifts. One of the most remarkable responses is plasticity, which is the ability of a single plant genotype to produce different phenotypes in response to environmental stimuli. As with all traits, the ability of plasticity to evolve depends on the presence of underlying genetic diversity within a population. A common approach for evaluating the role of genetic variation in driving differences in plasticity has been to study genotype-by-environment interactions (G x E). G x E occurs when genotypes produce different phenotypic...

Maximizing the effectiveness of fuel treatments at landscape scales is a key research and management need given the inability to treat all areas at risk from wildfire. We synthesized information from case studies that documented the influence of fuel treatments on wildfire events. We used a systematic review to identify relevant case studies and extracted information through a series of targeted questions to summarize experiential knowledge of landscape fuel treatment effectiveness. Within a larger literature search, we identified 18 case study reports that included (1) manager assessment...

Ecosystem transformations to altered or novel ecological states are accelerating across the globe. Indicators of ecological resilience to disturbance and resistance to invasion can aid in assessing risks and prioritizing areas for conservation and restoration. The sagebrush biome encompasses parts of 11 western states and is experiencing rapid transformations due to human population growth, invasive species, altered disturbance regimes, and climate change. We built on prior use of static soil moisture and temperature regimes to develop new, ecologically relevant and climate responsive...

A key uncertainty of empirical models of post-fire tree mortality is understanding the drivers of elevated post-fire mortality several years following fire, known as delayed mortality. Delayed mortality can represent a substantial fraction of mortality, particularly for large trees that are a conservation focus in western US coniferous forests. Current post-fire tree mortality models have undergone limited evaluation of how injury level and time since fire interact to influence model accuracy and predictor variable importance. Less severe injuries potentially serve as an indicator for...

The USDA Forest Service, Forest Inventory and Analysis (FIA) program constructs area estimates of forest attributes through a quasi-systematic sample of field plots distributed across the contiguous US. The program is under increasing pressure to provide estimates over small areas, for which the precision of FIA estimates is limited by small sample sizes. Small area estimation (SAE) models can improve the precision of estimates by leveraging relationships between forest attributes and auxiliary data across multiple small areas of interest. SAE models with large model domains are challenged...

Individual plant species play valuable roles in meeting restoration goals for pollinators. However, the selection of plant species for pollinator restoration is rarely informed using empirical evidence and is usually developed in agroecosystems, which experience frequent human interventions to ensure plant success as compared to seminatural ecosystems. We highlight concepts and future research needs to design planting mixes that fulfill the ecological requirements of pollinators in seminatural ecosystems. Native plants that are attractive to pollinators, increase the stability of pollinatio...

The federally endangered Sonoran pronghorn (Antilocapra americana sonoriensis; herein, pronghorn) is endemic to arid desert landscapes in the southwestern United States (U.S.) and northwestern Mexico. Historically, the range of Sonoran pronghorn in the U.S. extended east from the Salton Sea in California to Tucson and Nogales in Arizona and extended south from the Salton Sea and Phoenix, Arizona, to the border with Mexico (Phelps and Webb 1981, Krausman et al. 2005). Factors that contributed to the decline of pronghorn include habitat fragmentation, livestock grazing, and historical...