Treesearch

Fledgling encounter rates at sea were used as measures of annual reproductive performance for Common Murres Uria aalge and Marbled Murrelets Brachyramphus marmoratus over 29 years in two marine biogeographic regions off the coast of Oregon, USA, north and south of Cape Blanco. In both bioregions, the adult murre population was much larger and the encounter rate of murre fledglings was much higher than for murrelets overall, but the apparent decline in productivity during El Niño events and years of poor foraging was significantly greater in murres than in murrelets. We conclude that...

The efficacy of a spray-on combination formula containing the insecticides thiamethoxam and chlorantraniliprole was tested against subterranean termites using a covered ground proximity test. The test consisted of six treatments, five were chemical treatments and one was water control. Southern pine wood samples were treated with varying rates or treatment methods of the aforementioned insecticide combination, chlorantraniliprole alone, borate alone, or no chemical (water) treatment. Treated samples were installed at the Harrison Experimental Forest in Saucier, Mississippi using a modified...

Thermally modified wood (TMW) is a growing trend in North America in areas of low decay and insect pressure. Thermal modification improves dimensional stability, decreases moisture uptake, and results in a darkened color that resembles tropical hardwoods. More testing is needed in severe decay situations and in areas of high termite pressure to fully understand the boundaries of its material performance. Within the AWPA, the P9 subcommittee (non-biocidal wood protectants) has been working to develop test methodologies and appropriate use category designations for TMW materials. The Forest...

Fire-exclusion has acted as a major perturbation on dry conifer forests in the western United States, increasing tree density and, in mixed-conifer forests, the dominance of shade-tolerant species. Restoration efforts aim to reverse these effects by reducing stand density, restoring relative proportions of tree species, and reintroducing recurrent fire, but there are limited long-term data on the effects of repeated burning on tree regeneration. We analyzed two decades of seedling and overstory data from the Teakettle Experimental Forest in the southern Sierra Nevada, California, United...

White-nose syndrome (WNS) has notably affected the abundance of Myotis lucifugus(little brown myotis) in North America. Thus far, substantial mortality has been restricted to the eastern part of the continent where the cause of WNS, the invasive fungus Pseudogymnoascus destructans, has infected bats since 2006. To date, the state of Washington is the only area in the Western US or Canada (the Rocky Mountains and further west in North America) with confirmed cases of WNS in bats, and there the disease has spread more slowly than it did in Eastern North America. Here, we review differences...

A forester set up a large-scale, 1600-m fire-break trial with red alder (Alnus rubraBong.) inter-planted between Douglas-fir (Pseudotsuga menziesiiMirb Franco), after the extensive 1927 Yacolt Burn in the Columbia Gorge. This now 90-year-old trial demonstrates dramatic effects of alder on soils and growth of Douglas-fir; it also provides a timely lesson for foresters deciding what to do after recent similar fires in western Oregon and Washington. We used 2015 airborne lidar to re-examine the trial effects. Douglas-fir trees in stands mixed with alder (Strip) continue to grow taller than...

We present PNW-Cnet v4, a deep neural net with an associated Shiny-based application designed to facilitate efficient data processing to detect terrestrial wildlife species through passive acoustic monitoring. PNW-Cnet v4 is a deep convolutional neural network that detects audio signatures of 37 focal species of birds and mammals that inhabit forests of the Pacific Northwest, USA, along with other commonly occurring forest sounds. The primary objective of developing PNW-Cnet v4 was to support a long-term northern spotted owl (Strix occidentalis caurina) monitoring program. By incorporating...

High-resolution microscopy of deep tissue with large field-of-view (FOV) is critical for elucidating organization of cellular structures in plant biology. Microscopy with an implanted probe offers an effective solution. However, there exists a fundamental trade-off between the FOV and probe diameter arising from aberrations inherent in conventional imaging optics (typically, FOV < 30% of diameter). Here, we demonstrate the use of microfabricated non-imaging probes (optrodes) that when combined with a trained machine-learning algorithm is able to achieve FOV of 1x to 5x the probe diameter....

Past experiences influence choices, and people’s preferences for more similar (habit-forming) or different (variety-seeking) experiences are reflected in these choices. We develop a structural estimation framework to capture whether people are habit forming or variety seeking and apply it to the choice of recreation site. This research contributes to the revealed preference literature by demonstrating how to account for habit or variety-seeking behavior in recreation site choice models in a two-stage framework. Using this framework, we estimate similarity weights that reflect the birders...

Objective The literature on thermal refuges has focused on when fish use what kinds of refuge, but we address how refuge availability and characteristics affect population abundance and persistence under warming. Methods Population benefits of thermal refuges are very difficult to assess empirically, so we used InSTREAM, an individual-based trout population model. InSTREAM represents several ways temperature affects survival and growth, as mediated by behaviors such as deciding when and where to feed. The model’s credibility was established by showing that it closely reproduced 10 observed...