Firewood Movement Research Articles

Mortality of Bark- and Wood-boring Beetles (Coleoptera: Buprestidae, Cerambycidae, and Curculionidae) in Naturally Infested Heat-treated Ash, Birch, Oak, and Pine Bolts.

Firewood and wood packaging material (WPM) are major pathways for moving bark- and wood-infesting insects (borers). Heat treatment regulations for interstate firewood movement vary among U.S. states: from 56°C for 30 min to 71.1°C for 75 min. Current WPM international standards (ISPM 15) require heating to a minimum of 56°C for 30 min throughout the profile of the wood. Using bolts from infested ash (Fraxinus), birch (Betula), oak (Quercus), and pine (Pinus) trees in Michigan, we assessed borer mortality at core temperatures of 50, 53, 56, and 60°C maintained for 30 min in chambers set to 60, 65, 70, or 75°C. After treatment, bolts were monitored for adult emergence and later dissected to determine borer mortality rates. Mortality was high to complete for all heat treatments and increased with both increasing core and chamber temperatures. For the Agrilus (Buprestidae) species tested, there was complete mortality of Agrilus anxius on birch and Agrilus planipennis on ash when core temperatures of 56°C or higher were targeted regardless of chamber temperature. However, on oak, a few Agrilus bilineatus and Agrilus sulcicollis survived in bolts heated to 56°C in chambers at 60 and 65°C, and some A. sulcicollis survived in chambers set at 70 and 75°C. Similarly, a few pine-infesting borers survived heating to 56°C at all chamber temperatures. However, there was complete mortality in all hosts when bolts were heated to 60°C for 30 min, regardless of chamber temperature. Results are discussed in terms of current treatment regulations for firewood and WPM.

Firewood Transport as a Vector of Forest Pest Dispersal in North America: A Scoping Review.

Native and nonnative insects and diseases can result in detrimental impacts to trees and forests, including the loss of economic resources and ecosystem services. Increases in globalization and changing human behaviors have created new anthropogenic pathways for long distance pest dispersal. In North America, literature suggests that once a forest or tree pest is established, the movement of firewood by the general public for recreational or home heating purposes is one of the primary pathways for its dispersal. Understanding human perceptions and behaviors is essential to inform the most effective strategies for modifying firewood and pest dispersal by humans. This scoping review seeks to assess trends and gaps in the existing literature, as well as patterns in behavior related to forest pest dispersal through firewood movement in North America. We identified 76 documents that addressed this topic to which we applied inclusion and exclusion criteria to select articles for further analysis. Twenty-five articles met the inclusion criteria and were categorized based on five identified themes: 1) insect incidence in firewood, 2) insect dispersal via firewood, 3) recreational firewood movement, 4) firewood treatments, and 5) behavior and rule compliance. The selected articles show trends that suggest that firewood movement presents a risk for forest insect dispersal, but that behavior can be modified, and compliance, monitoring, and treatments should be strengthened. This scoping review found limited research about western United States, Mexico, and Canada, various insect species and other organisms, regulation and management, awareness, and behavioral dimensions of firewood movement.

Reducing Firewood Movement by the Public: Use of Survey Data to Assess and Improve Efficacy of a Regulatory and Educational Program, 2006–2015

This paper describes a program of policy management and research from 2006 through 2015. It focuses on regulator efforts to understand and address challenges presented by dispersal of forest diseases and invasive pests in firewood by the camping public. Five surveys conducted at two-year intervals informed these efforts. The first survey in 2006 benchmarked campers’ awareness of forest threats by invasive species, their evaluations of firewood supplied at and near Wisconsin state parks, and their compliance with firewood movement rules which had been implemented that year. The 2008 survey tested for improvements in awareness and compliance and investigated campers’ motivations. The motivation research showed that calculated, normative, and social motivations are all important to rule compliance in the camping context. Surveys in 2010, 2012, and 2014 confirmed these results and guided education and outreach efforts, adjustments to firewood movement rules for Wisconsin state parks and forests, and improvements to firewood supplies at state campgrounds. The survey sequence as a whole revealed that: (1) compliance improves dramatically in early program years and then levels off, suggesting that it may be unrealistic and cost ineffective to strive for 100% compliance in similar regulatory contexts; (2) persistence in messaging is important in building awareness and motivation; and (3) regulation and persuasion based on motivational principles can extend beyond specific situations where informing and regulating take place, suggesting that public properties can be useful venues for encouraging other types of environmentally responsible behavior.

Coupled Human-Environment Dynamics of Forest Pest Spread and Control in a Multi-Patch, Stochastic Setting.

BackgroundThe transportation of camp firewood infested by non-native forest pests such as Asian long-horned beetle (ALB) and emerald ash borer (EAB) has severe impacts on North American forests. Once invasive forest pests are established, it can be difficult to eradicate them. Hence, preventing the long-distance transport of firewood by individuals is crucial.MethodsHere we develop a stochastic simulation model that captures the interaction between forest pest infestations and human decisions regarding firewood transportation. The population of trees is distributed across 10 patches (parks) comprising a “low volume” partition of 5 patches that experience a low volume of park visitors, and a “high volume” partition of 5 patches experiencing a high visitor volume. The infestation spreads within a patch—and also between patches—according to the probability of between-patch firewood transportation. Individuals decide to transport firewood or buy it locally based on the costs of locally purchased versus transported firewood, social norms, social learning, and level of concern for observed infestations.ResultsWe find that the average time until a patch becomes infested depends nonlinearly on many model parameters. In particular, modest increases in the tree removal rate, modest increases in public concern for infestation, and modest decreases in the cost of locally purchased firewood, relative to baseline (current) values, cause very large increases in the average time until a patch becomes infested due to firewood transport from other patches, thereby better preventing long-distance spread. Patches that experience lower visitor volumes benefit more from firewood movement restrictions than patches that experience higher visitor volumes. Also, cross–patch infestations not only seed new infestations, they can also worsen existing infestations to a surprising extent: long-term infestations are more intense in the high volume patches than the low volume patches, even when infestation is already endemic everywhere.ConclusionsThe success of efforts to prevent long-distance spread of forest pests may depend sensitively on the interaction between outbreak dynamics and human social processes, with similar levels of effort producing very different outcomes depending on where the coupled human and natural system exists in parameter space. Further development of such modeling approaches through better empirical validation should yield more precise recommendations for ways to optimally prevent the long-distance spread of invasive forest pests.

Heat Treatment of Firewood for Emerald Ash Borer (<I>Agrilus planipennis</I> Fairmaire): Case Studies

The movement of firewood within emerald ash borer (Agrilus planipennis Fairmaire) (EAB)-infested states and into adjoining areas has been a contributor to its spread throughout the United States and Canada. In an effort to prevent further human-aided spread of EAB and to facilitate interstate commerce, the USDA Animal and Plant Health Inspection Service and cooperating states in the EAB quarantine have established a heat treatment process to be used as a mitigating treatment to allow movement of firewood from EAB quarantine areas. Firewood producers have since been faced with challenges implementing heat treatment processes and meeting the treatment standard for firewood. In this article, we present four case studies, conducted at firewood heat treatment facilities, with the aim of addressing these challenges. Different heat treating strategies were used in each of these facilities to meet the particular needs of operation. A step-by-step operating procedure was developed for heat treatment operation and temperature monitoring of both kiln and firewood samples during the heating process.

Motivations for rule compliance in support of forest health: Replication and extension

This study replicates and extends research conducted in 2008. Based on a random sample of 800 campers who used Wisconsin state parks and forests in 2010, it confirms that calculated, normative, and social motivations are all important determinants of firewood movement rule compliance, a context where regulatees have primarily sporadic short-term interests, and where costs of compliance and non-compliance are both low. The study uses bi-variate statistical tests and recursive partitioning (standard and conditional permutation random forests) for analysis, and discusses findings from the perspective of a natural resources regulator of activities in multiple domains (e.g., business and recreational uses of forests in both rural and urban settings). It demonstrates how knowledge of motivations for compliance can inform two integrative research and analysis frameworks – motivational postures and social marketing, and discusses how affect and social norms may be utilized to improve regulator effectiveness.

Motivation for compliance with environmental regulations related to forest health

This study extends previous research on motivations for compliance with environmental regulations. It addresses contexts where regulatees have primarily sporadic short term interests, where costs of compliance are modest, and where costs of non-compliance are low. The behavior studied is the movement of firewood for camping, a principal cause for the spread of the emerald ash borer (Agrilus planipennis), one of several invasive species plaguing the eastern United States. Based on a three-wave mail survey that produced 495 usable returns (64% response rate), findings suggest that motivations are influential in these contexts. Calculated motivations exert the greatest influence—especially when related to firewood price and convenience, while normative motivations (civic duty based) exert less influence, as does ability to comply. These findings have important implications, not only for controlling the spread of forest diseases and invasive pests, but also for regulating natural resources in general. They suggest that national, state, and local governments can manage natural resources to encourage user compliance with environmental rules, and develop communication strategies that leverage pro-environment norms.

Forest stand composition and impacts associated with Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae) and Agrilus coxalis Waterhouse in oak woodlands

From 2009–2011, we assessed the impact of the goldspotted oak borer, Agrilus auroguttatus Schaeffer, or its sibling species, Agrilus coxalis Waterhouse, at locations in southern California (denoted infested: ICA and uninfested: UCA), southeastern Arizona (AZ), and southern Mexico (MX). Our surveys examined forest composition of oak woodlands; the degree of injury and proportion of oaks infested with either A. auroguttatus (ICA and AZ) or A. coxalis (MX); and the progression of aerially mapped oak mortality in San Diego Co. (ICA). By most measures of impact that we evaluated, the effect on oaks by the two Agrilus spp. was relatively low in their native regions, but significantly higher by A. auroguttatus at ICA sites. Larger diameter red oak species have been the preferred hosts of A. auroguttatus in AZ and ICA sites, and red oaks greater than approx. 13cm in DBH throughout California are likely at risk of injury from this invasive pest. At sites in AZ there was no evidence of infestation by A. auroguttatus on living or dead white oak species, whereas at ICA sites we recorded a minor amount of infestation by A. auroguttatus on living individuals of a white oak species (Quercus engelmannii Greene), but no mortality. In contrast, a white oak from MX sites (Quercus peduncularis) was more frequently infested by A. coxalis than were indigenous red oaks. Across all ICA sites, A. auroguttatus has infested 61% of the live larger diameter oaks and killed 13% of the oak component of the forest (vs. 4% infested and 2% dead in AZ, respectively). At survey plots near the predicted origin of the outbreak in CA, over 90% of the larger diameter red oaks have been infested. Nearly 90% of the dead oaks surveyed across all ICA sites showed evidence of previous injury symptoms from A. auroguttatus. Aerial oak mortality polygons associated with A. auroguttatus have expanded ∼50km in nine years, but our analysis confirms that the outbreak appears to still be confined to San Diego Co. The distance of oak mortality polygons from the predicted origin of the outbreak explained the most variance in a principal component analysis. The invasive population of A. auroguttatus is a significant conservation and ecological threat to the oak woodlands of California and should be managed accordingly, especially by restricting firewood movement.

What Does “Local” Firewood Buy You? Managing the Risk of Invasive Species Introduction

Firewood can serve as a vector in the transport of non-native species, including wood-boring insects that feed within the wood and thus can be transported accidentally. Governments have enacted limitations on the movement of firewood in an effort to limit the anthropogenic movement of non-native species through, for example, recreational camping. Although the movement of invasive species through firewood is a documented invasion pathway, it is not trivial for governments to determine a "safe" allowable distance for moving firewood. We were motivated by this challenge and developed a theoretical simulation to determine the campgrounds that could be potentially exposed to infested firewood based upon the hypothetical distribution of an invasive species and the allowable distance for moving firewood. We extend this concept to the known distributions of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) and Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) Coleoptera: Cerambycidae). We illustrate, based upon theoretical and empirical observations, that as the distribution of an invasive species increases, more rigid constraints on the movement of firewood would be required relative to those species that are distributed over a smaller scale. Also, on the level of management within a state, smaller states have far less margin for error than larger ones, as even extremely rigid restrictions on the movement of firewood could have little management effect unless the infested area is spatially limited. These results collectively suggest the potential for a dynamic management strategy that adjusts allowable distances for firewood movement based upon the distribution of the non-native species.