Treesearch

The level of tree mortality and drought observed over the past decade in North America has been described as ‘unparalleled’ in our modern history, in particular in the Sierra Nevada, California. Forest managers could use early warning of where and how much tree mortality to expect in the very near future to plan and prioritize hazard tree removal, pest suppression activities, infer location of funding needs and fuels reduction treatments as well as access for firefighting. To answer these needs, we developed an empirically-based forecast model for expected tree mortality for an upcoming...

Spatial synchrony, defined as correlated temporal fluctuations among populations, is a fundamental feature of population dynamics, but many aspects of synchrony remain poorly understood. Few studies have examined detailed geographical patterns of synchrony; instead most focus on how synchrony declines with increasing linear distance between locations, making the simplifying assumption that distance decay is isotropic. By synthesising and extending prior work, we show how geography of synchrony, a term which we use to refer to detailed spatial variation in patterns of synchrony, can be...

The North American Porcupine (Erethizon dorsatum) is one of the most widely distributed mammals in North America, but recent reports have suggested declines in parts of its range in the West. In California, little is known about the historical or current status of the porcupine, and maps of its distribution conflict considerably. Nevertheless, the species is of interest to natural resource managers. For much of the 1900s, foresters and others primarily treated porcupines as pests because of the undesirable damage they inflict feeding on trees and gnawing on manmade items in search of salt....

Following changes in vegetation structure and pattern, along with a changing climate, large wildfire incidence has increased in forests throughout the western U.S. Given this increase there is great interest in whether fuels treatments and previous wildfire can alter fire severity patterns in large wildfires. We assessed the relative influence of previous fuels treatments (including wildfire), fire weather, vegetation and water balance on fire severity in the Rim Fire of 2013. We did this at three different spatial scales to investigate whether the influences on fire severity changed...

The emerald ash borer (EAB) Agrilus planipennis, first detected in 2002 in the vicinity of Detroit, Michigan, USA, has spread throughout much of eastern and midwestern North America as of 2016, resulting in widespread mortality of ash trees in the genus Fraxinus. We investigated the effects of this newly available, exotic food source on populations of six species of largely resident insectivorous birds, including five species of woodpeckers and whitebreasted nuthatch (Sitta canadensis), using North American Breeding Bird Survey data for breeding season estimates and Audubon Christmas Bird...

Anoplophora glabripennis, the Asian Longhorned Beetle (ALB), is an invasive species of high economic and ecological relevance given the potential it has to cause tree damage, and sometimes mortality, in the United States. Because this pest is introduced by transport in wood-packing products from Asia, ongoing trade activities pose continuous risk of transport and opportunities for introduction. Therefore, a geographic understanding of the spatial distribution of risk factors associated with ALB invasions is needed. Chief among the multiple risk factors are (a) the potential for infestation...

Water quality in the Midwestern United States is threatened as a result of agricultural runoff. Based on self-reported data from a survey of farmers in Indiana, we aim to provide a better understanding of how awareness of water quality problems, farm-as-business attitudes, and stewardship attitudes are related to each other and willingness to improve water quality. More specifically, we propose and test a structural equation model grounded in dual-interests theory to examine if and to what extent the relationships between awareness and farm-as-business attitudes are mediated by stewardship...

We examined streamwater concentration-discharge relationships for eight small, forest watersheds ranging in elevation from 1,485 to 2,465 m in the southern Sierra Nevada. These headwater streams revealed nearly chemostatic behavior by current definitions for K+, Ca2+, Mg2+, Na+, Cl- and SO42- in most cases but not for NH4+. NO3-, or ortho-P. The latter ions were somewhat enriched during high flows. All ions studied showed a dilution process at lower flows (< 50 l sec−1) with the concentration-discharge relationship being more chemostatic at higher flows. While previous studies in the...

What are the market conditions for woodworkers involved in construction-based sectors and what investments are planned to improve capabilities in the current business environment? For a fifth straight year, construction-based mar­kets continued their growth trends in 2016, as U.S. spending on single family housing, multi-family housing, and nonresidential construction all in­creased, with repair and remodeling increasing for a fourth straight year, according to the U.S. Census Bureau. Total value of construction put in place in these sectors was $877 billion in 2016. It's against this...

Straw mulch is commonly used for post-fire erosion control in severely burned areas but this practice can introduce non-native species, even when certified weed-free straw is used. Rice straw has recently been promoted as an alternative to wheat under the hypothesis that non-native species that are able to grow in a rice field are unlikely to establish in dry forested habitats. We investigated this hypothesis in the severely burned areas of the 2013 Rim Fire in the Sierra Nevada that were treated with rice straw post-fire. In 2014, we installed 134 plots in mulched and control areas with...