Treesearch

Background: Experimental forests present unrivaled opportunities to understand the factors influencing vegetation structure many decades after silvicultural treatments or natural disturbances. In this study, we use the western larch-dominated moist mixed-conifer forests at Miller Creek Demonstration Forest (Miller Creek) to better understand the relationship between current vegetation structure, 55 years after two forms of high-intensity disturbance (clearcutting plus broadcast burning, and a high-severity wildfire) and characteristics of the site, the disturbance, and pre-disturbance...

Reforestation success in areas impacted by high-severity wildfire and seasonal moisture limitations require nursery-grown seedlings capable of establishing and surviving in harsh environments. Drought conditioning (i.e. restricted irrigation regimes) has the potential to improve planting outcomes, although assessments of effectiveness based on replicated field trials in operational settings are rare. In 2022, we conducted a drought conditioning experiment on second-year stock of ponderosa pine (Pinus ponderosa), western white pine (Pinus monticola) and two seed sources of western larch...

The Northern Rocky Mountains region includes 42 million acres of forest land which is diverse in landownership, management objectives, tree species, site productivities, disturbance regimes, and silvicultural practices resulting in a mosaic landscape. Substantial changes in landownership, management objectives, markets, policy, forest conditions, and silvicultural practices have occurred over the last thirty years. This review provides a synopsis of these changes across different forest types in the region. The U.S. Department of Agriculture, Forest Service remains the largest forest...

Understanding how species-specific traits and density-dependent competition modulate the effects of extreme climate events is essential for informing future forest management strategies. We analyzed the radial growth of western larch (Larix occidentalis) and Douglas-fir (Pseudotsuga menziesii var. glauca) trees growing in unmanaged old-growth stands — and western larch grown at two experimentally controlled densities — at four sites across western Montana, USA. Differences in leaf habit (deciduous vs. evergreen) and divergent water use strategies (anisohydric vs. isohydric) of western...

Greece is facing a wildfire crisis that parallels many other countries in fire-prone regions around the globe. Recent wildfire data for Greece point to an alarming trend of increasing fire size and severity catalyzed by climate change, lack of forest and fuel management, urban expansion into wildlands around major population centers, and rural exodus from areas that traditionally supported fire-resilient land uses. Fire management in Greece has long emphasized suppression with relatively little attention to prevention and coordination. In this paper, we identify key factors that are...

The unprecedented 2022 wildfire season in Navarra, northern Spain, marked a turning point in regional wildfire management, when seven simultaneous large fires during a June heatwave burned more than 17,000 ha in just a few days, overwhelming suppression capacity and highlighting the limits of a strategy based primarily on ignition prevention and fire suppression. In this study, we implemented a stochastic wildfire modeling system based on the Minimum Travel Time algorithm, historical ignition patterns, spatial fuel data, and spatiotemporal weather variability to assess community and...

A relatively small number of rapidly spreading wildfire events burn disproportionately large areas. But beyond area burned, do fast fires produce distinct postfire ecological outcomes? Here, we measure daily linear fire growth rates and assess relationships between fire spread, burn severity, and metrics of postfire landscape resilience from 3499 fires occurring between 2012 and 2023 in conifer-dominated forests of Canada and the western US. We find that as linear spread rate increases, so too does fire severity, proportion of area burned at high severity, and distance to surviving live...

Background: Changes in climate and vegetation, in combination with fire exclusion, are altering and homogenizing fire regime attributes compared to historical conditions. Fire regime changes are commonly quantified using departure metrics based on differences in measures of central tendency (i.e., means) between time periods. These metrics can mischaracterize complex changes to fire regime attributes because the distributions underlying these attributes are often not well described by parameters.

Results: We developed a non-parametric index of fire regime departure that quantifies...

Springsnails in the genus Pyrgulopsis in western North America have long been a dilemma for taxonomists. Defining species boundaries has been complicated by the presence of undiscovered or cryptic taxa, range over- or underestimation, species complexes representing an unknown number of species, and named species synonymous with other taxa. To address these issues, we conducted an array of molecular species delimitation analyses using sequences from up to 2 mitochondrial and 2 nuclear genes from over 5000 specimens representing 140 of the 151 currently recognized taxa. These analyses...

Maps of aboveground biomass density (AGBD) estimated from remote sensing data with models trained from inventory data are essential for carbon monitoring. Forest inventory plots in the United States (US) are measured by the forest inventory and analysis (FIA) program of the US Forest Service (USFS). These plots are spatially representative, design unbiased, and provide estimates of AGBD and other forest attributes over large spatial domains, but do not provide spatially continuous or sufficiently precise estimates over small spatial domains (e.g. forest stands). Integration with remote...