Treesearch

Disturbance is an integral component of forest ecosystems. Therefore, contemporary changes to the frequency and severity of disturbances in forests may have lasting ecological consequences. In recent decades, widespread mountain pine beetle (MPB; Dendroctonus ponderosae) outbreaks have contributed more to total tree mortality than other disturbances such as wildfire. Past studies have used a broad range of measurements to evaluate the local effects of beetle outbreaks on birds (e.g., dead trees per acre versus percent mortality) and this has led to some challenges and inconsistencies in...

The vast majority of measurements in the field of plant hydraulics have been on small‐diameter branches from woody species. These measurements have provided considerable insight into plant functioning, but our understanding of plant physiology and ecology would benefit from a broader view, because branch hydraulic properties are influenced by many factors. Here, we discuss the influence that other components of the hydraulic network have on branch vulnerability to embolism propagation. We also modelled the impact of changes in the ratio of root‐to‐leaf areas and soil texture on vulnerabilit...

Plant gas exchange systems are widely used to study leaf physiological processes and properties such as stomatal function and the maximum carboxylation rate of Rubisco. Increasingly, these systems are used to assess how leaf gas exchange varies with temperature in order to better understand how rising temperature will impact plant function. Examples of such studies include variation in optimal temperatures of photosynthesis as a function of species and growth environment, and respiratory acclimation to higher temperatures. Leaf thermoregulation leading to homeothermy has been reported...

In order to increase the pace and scale of managing forests to reduce wildfire risk in the western U.S., federal agencies have adopted policies that promote an all lands management (ALM) approach, which extends management actions across jurisdictional boundaries. To better implement such policies, ALM approaches require new governance systems that overcome barriers found in existing systems, which typically address jurisdictions separately. Polycentric governance systems, characterized by multiple and diverse actors at different scales operating in coordination with one another under an...

Fuel reduction treatments are designed to meet multiple management objectives, resulting in unique vegetation structures that do not conform to standard classifications and vary considerably over space and time. We evaluated how different post-treatment vegetation structures relate to patterns in wildfire severity. To reconstruct both untreated and treated pre-fire forest structure, we used post-fire stand data measured at three different fuel treatment units burned by the 2011 Wallow Fire (Arizona). We describe (1) how forest structure differs among the treatment units, both in the...

Accounting for externalities generated by fire spread is necessary for managing fire risk on landscapes with multiple owners. In this paper, we determine the optimal management of a synthetic landscape parameterized to represent the ecological conditions of Douglas-fir (Pseudotsuga menziesii) plantations in southwest Oregon. The problem is formulated as a dynamic game, where each agent maximizes their own objective without considering the welfare of the other agents. We demonstrate a method for incorporating spatial information and externalities into a dynamic optimization process. A...

Knowledge of the spatiotemporal variability of abundance and vital rates is essential to the conservation of wildlife populations. In Pacific Northwest forests, previous small mammal research has focused on estimating abundance; few studies have focused on vital rates. We used robust design temporal symmetry models and livetrapping data collected 2011–2016 at nine sites to estimate apparent annual survival, population growth rate, andrecruitment of Humboldt’s flying squirrels (Glaucomys oregonensis) and Townsend’s chipmunks (Neotamias townsendii) in a late-successional forest of the...

Background: Tree species in the genus Cedrela P. Browne are threatened by timber overexploitation across theNeotropics. Genetic identification of processed timber can be used to supplement wood anatomy to assist in thetaxonomic and source validation of protected species and populations of Cedrela. However, few genetic resourcesexist that enable both species and source identification of Cedrela timber products. We developed several ‘omicresources including a leaf transcriptome, organelle genome (cpDNA), and diagnostic single nucleotide polymorphisms(SNPs) that may assist the classification...

The 2011–2014 removal of two large dams on the Elwha River, Washington State, the largest dam removal yet completed globally, created extensive cutbank exposures of reservoir sediments, allowing the first characterization of the facies architecture of sediments through direct observation in reservoirs worldwide and providing an unparalleled opportunity to assess the relationship between environmental influences, such as changes in sediment supply, and their expression in the stratigraphic record. Using a combination of facies description from observation of 49 measured sections and >100...

This short commentary piece explores the concept of shared stewardship in the Forest Service as it relates to recreation planning and management. It offers examples of different types of networks of partners.