Treesearch

Wood Turtle (Glyptemys insculpta) populations are declining in many portions of the species’ native range due to multiple factors that might influence functional connectivity and population genetic structure. We used 13 microsatellite markers to examine patterns of genetic structure in the Wood Turtle across its native range in Eastern and Midwestern North America. For n = 45 collections with 15 or more individuals (total N = 1,258), multiple clustering approaches revealed two major genetic groups corresponding to the midwestern and eastern collections. Interestingly, a sample from lower...

Spanish juniper, Juniperus thurifera L, forests are typically managed as uneven-aged forests in the Iberian range, which requires information about site index (SI) classes and diameter at breast height (dbh) distributions. The objective of this study is to evaluate and compare the performance of remote sensing models using multitemporal airborne laser scanning (ALS) data, Landsat metrics of state and change along with topographic, geographic and climatic predictors for the prediction of SI classes and diameter distributions. The best model for SI classes was a logistic model that showed an...

In 2020, six wildfires burned more than 1 million acres over the Labor Day weekend in Oregon. Jeremy Fried, a research forester with the U.S. Forest Service, Pacific Northwest Research Station, saw an opportunity to study how these wind-driven megafires affected forest structure and carbon storage, and how forest structure before the fires may have influenced fire severity.With research fellows Sebastian Busby and Angela Klock, Fried developed a model that estimated wind speed when wildfire entered forest plots previously inventoried through the national Forest Inventory and Analysis...

Background: The reintroduction of fire, with the goal of reducing fuels and restoring forest resilience, is a critical management practice in dry conifer forests of the western United States. In dry forest landscapes, invasion by non-native annual grasses could complicate restoration goals if fire exacerbates invasion and associated impacts, particularly in areas with low tree cover and in adjacent open areas. Although annual grasses are becoming increasingly pervasive across the West, little is known about how species differ in their response to burning, especially in historically...

Restoration of dry forest landscapes of the Pacific Northwest often involves the removal of some closed-canopy forest that has expanded due to fire exclusion, but this can conflict with species conservation when species require closed-canopy forest as part of their habitat. Fire refugia—areas within fire perimeters that burn less severely or frequently—might provide a solution to this conflict. We used a species-specific approach to understanding fire refugia for northern spotted owls to model the post-fire persistence of nesting and roosting (NR) forest in the frequent fire landscapes of...

As wildfires in the western US grow in both size and intensity, forest policymakers and managers seek effective ways to mitigate and adapt to increasing wildfire risk. In some regions, such as the western Pacific Northwest, where wildfires historically burned infrequently, climate change and housing development appear to be altering wildfire regimes while bringing greater numbers of people living in greater proximity to potentially more fire-prone forests. Developing effective strategies for family forest owners to adapt to the wildfire regimes of the future will depend on designing...

Keystone trophic interactions have disproportionate impacts on the structure and function of ecosystems by regulating the flow of nutrients through food webs. However, human disturbances alter animal habitat use and foraging behavior, with uncertain consequences for trophic interactions and the ecosystem functions they support. We simulated human activities to manipulate a keystone process—animals transporting salmon-derived nutrients from aquatic to terrestrial ecosystems—and documented the effects on animal behaviors and associated ecosystem functions. We used acoustic playbacks to alter...

Background: Wildfire can dramatically influence terrestrial landscapes, but effects on biodiversity can be hidden beneath the water’s surface. Following the 2020 Labor Day wildfires in Oregon’s western Cascade Mountain Range, we sampled 25 Oregon streams and 6 Washington streams representing a gradient of fire severity and pre-fire forest stand age to determine the effects of megafires on watershed biodiversity. In each watershed we used environmental DNA (eDNA) metabarcoding and traditional field surveys (Surber or electrofishing) to assess biodiversity.Results: Our results suggest...

Widespread mortality poses a major conservation challenge for foundation species whitebark pine (Pinus albicaulis Engelm.). We assessed whitebark pine forest structure, composition, and persistence potential in Idaho and Nevada, USA following mountain pine beetle (MPB), wildfire, and no recent disturbance by comparing overstory and regeneration relative abundances, classifying postdisturbance communities, and gauging persistence via residual mature trees and seedlings. Wildfire mortality spanned all species and sizes and exceeded MPB mortality, which was limited to larger pines. Disturbance...

Old growth forests in coastal Alaska and British Columbia represent some of the most expansive temperate rainforests on Earth, supporting high biodiversity, substantial carbon stocks, and the cultural heritage of Indigenous communities. Despite their importance, spatially consistent information on the distribution of old growth and mature forests in this region remains limited. We addressed this gap by integrating data across two national forest inventory programs with remotely sensed predictors. Forest inventory plots were classified by forest type and successional status (old growth,...