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Denys Yemshanov
Natural Resources Canada, Canadian Forest Service, Great Lakes Forestry Centre, 1219 Queen Street East, Sault Ste. Marie, ON P6A 2E5, Canada

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Journal article
Published: 19 June 2021 in Forests
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When adopted, wildlife protection policies in Canadian forests typically cover large areas and affect multiple economic agents working in these landscapes. Such measures are likely to increase the costs of timber for forestry companies operating in the area, which may hinder their acceptance of the policies unless harvesting remains profitable. We propose a bi-level wildlife protection problem that accounts for the profit-maximizing behavior of forestry companies operating in an area subject to protection. We consider the regulator with a wildlife protection mandate and forestry companies licensed to harvest public forest lands. We depict the relationship between the regulator and forestry companies as a leader-follower Stackelberg game. The leader sets the protected area target for each license area and the followers adjust their strategies to maximize payoffs while meeting the protection target set by the leader. The leader’s objective is to maximize the area-wide protection of spatially contiguous habitat while accounting for the followers’ profit-maximizing behavior. We apply the approach to investigate habitat protection policies for woodland caribou in the Churchill range, Ontario, Canada. We compare the game-theoretic solutions with solutions that do not consider the forest companies’ objectives and also with solutions equalizing the revenue losses among the companies.

ACS Style

Denys Yemshanov; Robert Haight; Ning Liu; Robert Rempel; Frank Koch; Art Rodgers. Balancing Large-Scale Wildlife Protection and Forest Management Goals with a Game-Theoretic Approach. Forests 2021, 12, 809 .

AMA Style

Denys Yemshanov, Robert Haight, Ning Liu, Robert Rempel, Frank Koch, Art Rodgers. Balancing Large-Scale Wildlife Protection and Forest Management Goals with a Game-Theoretic Approach. Forests. 2021; 12 (6):809.

Chicago/Turabian Style

Denys Yemshanov; Robert Haight; Ning Liu; Robert Rempel; Frank Koch; Art Rodgers. 2021. "Balancing Large-Scale Wildlife Protection and Forest Management Goals with a Game-Theoretic Approach." Forests 12, no. 6: 809.

Original paper
Published: 04 June 2021 in Optimization Letters
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Protecting wildlife corridors is a common management problem in regions of industrial forestry. In boreal Canada, human disturbances have negatively affected woodland caribou populations (Rangifer tarandus caribou), which prefer to function in large undisturbed areas. We present a linear programming model that allocates a fixed-width corridor between isolated caribou ranges and estimates its impact on harvest activities. Our corridor placement problem minimizes total resistance for caribou passing through the corridor, which is protected by a prohibition on all economic activities. We link this corridor placement problem with a harvest planning problem that maximizes the net revenues from harvest minus the cost of building and maintaining forest access roads. We depict gradual expansion of the forest road network over time as a multi-temporal network flow problem. We applied our approach to explore corridor options for connecting caribou populations in the Lake Superior Coast Range, with the Nipigon and Pagwachuan Ranges in the Kenogami-Pic Forest, in northern Ontario, Canada. Our results revealed two locations where corridor placement is cost-effective. Optimal corridor placement depends on the perception of the severity of the impact of roads on caribou populations and decision-making objectives. When the negative impact of roads is perceived to be high and/or maximizing harvest revenues is important, the optimal corridor location is in the eastern part of the study area. However, it is optimal to place the corridor in the western part of the area when the negative impact of roads is perceived to be small or the shortest corridor is desired.

ACS Style

Denys Yemshanov; Robert G. Haight; Ning Liu; Rob Rempel; Frank H. Koch; Art Rodgers. Exploring the tradeoffs among forest planning, roads and wildlife corridors: a new approach. Optimization Letters 2021, 1 -42.

AMA Style

Denys Yemshanov, Robert G. Haight, Ning Liu, Rob Rempel, Frank H. Koch, Art Rodgers. Exploring the tradeoffs among forest planning, roads and wildlife corridors: a new approach. Optimization Letters. 2021; ():1-42.

Chicago/Turabian Style

Denys Yemshanov; Robert G. Haight; Ning Liu; Rob Rempel; Frank H. Koch; Art Rodgers. 2021. "Exploring the tradeoffs among forest planning, roads and wildlife corridors: a new approach." Optimization Letters , no. : 1-42.

Perspective
Published: 26 November 2020 in Emerging Topics in Life Sciences
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When alien species make incursions into novel environments, early detection through surveillance is critical to minimizing their impacts and preserving the possibility of timely eradication. However, incipient populations can be difficult to detect, and usually, there are limited resources for surveillance or other response activities. Modern optimization techniques enable surveillance planning that accounts for the biology and expected behavior of an invasive species while exploring multiple scenarios to identify the most cost-effective options. Nevertheless, most optimization models omit some real-world limitations faced by practitioners during multi-day surveillance campaigns, such as daily working time constraints, the time and cost to access survey sites and personnel work schedules. Consequently, surveillance managers must rely on their own judgments to handle these logistical details, and default to their experience during implementation. This is sensible, but their decisions may fail to address all relevant factors and may not be cost-effective. A better planning strategy is to determine optimal routing to survey sites while accounting for common daily logistical constraints. Adding site access and other logistical constraints imposes restrictions on the scope and extent of the surveillance effort, yielding costlier but more realistic expectations of the surveillance outcomes than in a theoretical planning case.

ACS Style

Frank H. Koch; Denys Yemshanov; Robert G. Haight; Chris J.K. MacQuarrie; Ning Liu; Robert Venette; Krista Ryall. Optimal invasive species surveillance in the real world: practical advances from research. Emerging Topics in Life Sciences 2020, 4, 513 -520.

AMA Style

Frank H. Koch, Denys Yemshanov, Robert G. Haight, Chris J.K. MacQuarrie, Ning Liu, Robert Venette, Krista Ryall. Optimal invasive species surveillance in the real world: practical advances from research. Emerging Topics in Life Sciences. 2020; 4 (5):513-520.

Chicago/Turabian Style

Frank H. Koch; Denys Yemshanov; Robert G. Haight; Chris J.K. MacQuarrie; Ning Liu; Robert Venette; Krista Ryall. 2020. "Optimal invasive species surveillance in the real world: practical advances from research." Emerging Topics in Life Sciences 4, no. 5: 513-520.

Research article
Published: 18 November 2020 in Ecological Solutions and Evidence
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Multi‐day survey campaigns are critical for timely detection of biological invasions. We propose a new modelling approach that helps allocate survey inspections in a multi‐day campaign aimed at detecting the presence of an invasive organism. We adopt a team orienteering problem to plan daily inspections and use an acceptance sampling approach to find an optimal surveillance strategy for emerald ash borer in Winnipeg, Manitoba, Canada. The manager's problem is to select daily routes and determine the optimal number of host trees to inspect with a particular inspection method in each survey location, subject to upper bounds on the survey budget, daily inspection time, and total survey time span. We compare optimal survey strategies computed with two different management objectives. The first problem minimizes the expected number of survey sites (or area) with undetected infestations. The second problem minimizes slippage – the expected number of undetected infested trees in sites that were not surveyed or where the surveys did not find infestation. We also explore the impact of uncertainty about site infestation rates and detection probabilities on the surveillance strategy. Accounting for uncertainty helps address temporal and spatial variation in infestation rates and yields a more robust surveillance strategy. The approach is generalizable and can support delimiting survey programs for biological invasions at various spatial scales.

ACS Style

Denys Yemshanov; Robert G. Haight; Chris J. K. MacQuarrie; Frank H. Koch; Ning Liu; Robert Venette; Krista Ryall. Optimal planning of multi‐day invasive species surveillance campaigns. Ecological Solutions and Evidence 2020, 1, 1 .

AMA Style

Denys Yemshanov, Robert G. Haight, Chris J. K. MacQuarrie, Frank H. Koch, Ning Liu, Robert Venette, Krista Ryall. Optimal planning of multi‐day invasive species surveillance campaigns. Ecological Solutions and Evidence. 2020; 1 (2):1.

Chicago/Turabian Style

Denys Yemshanov; Robert G. Haight; Chris J. K. MacQuarrie; Frank H. Koch; Ning Liu; Robert Venette; Krista Ryall. 2020. "Optimal planning of multi‐day invasive species surveillance campaigns." Ecological Solutions and Evidence 1, no. 2: 1.

Research article
Published: 21 September 2020 in Natural Resource Modeling
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Industrial forestry in boreal regions increases fragmentation and may decrease the viability of some wildlife populations, particularly the woodland caribou, Rangifer tarandus caribou. Caribou protection often calls for changes in forestry practices, which may increase the cost and reduce the available timber supply. We present a linear programming model that assesses the trade‐off between habitat protection and harvesting objectives by combining harvest scheduling and optimal habitat connectivity problems. We formulate the habitat connectivity model as a network flow problem that maximizes the amount of habitat connected over a desired time span in a forested landscape, while the forestry objective maximizes net undiscounted revenues from timber harvest subject to even harvest flow and environmental sustainability constraints. We applied the approach to explore the trade‐off between caribou habitat protection and harvesting goals in the Armstrong‐Whitesand Forest, Ontario, Canada, a boreal forest area with prime caribou habitat. Our model also incorporates Dynamic Caribou Harvesting Scheduling (DCHS), a harvest policy currently in a place in Ontario that aims to balance the forest management and caribou protection goals in northern boreal regions. In our study area, the implementation of DCHS appears to have relatively minor impact on timber supply cost. By comparison, maximizing the protection of caribou habitat would lead to a noticeable increase of the mill gate timber cost by $3.3 m−3 on average, while enabling habitat protection in an additional 5.0%–9.5% of the range area. Our model is generalizable and can be adapted for assessing habitat recovery and harvest goals in other regions. Recommendations for Resource Managers: Incorporating the concept of long‐term habitat connectivity into forest planning can help reduce the negative impacts of harvest activities on caribou populations. Prioritizing habitat connectivity leads to a small increase in the overall harvest area because harvest has to be allocated to less productive and more geographically isolated sites to protect prime wildlife habitat containing old conifer stands. Maximizing the habitat protection would lead to a noticeable increase of the timber supply cost (by $3.3 m−3 on average), while enabling moderate increase of the protected habitat area (i.e., an additional 5.0%–9.5% of the range area). Implementation of Dynamic Caribou Harvest Schedules, which is the current harvesting policy in Ontario's boreal forests when caribou populations are present, causes only a minor increase of the timber supply cost in our study area.

ACS Style

Denys Yemshanov; Robert G. Haight; Rob Rempel; Ning Liu; Frank H. Koch. Protecting wildlife habitat in managed forest landscapes—How can network connectivity models help? Natural Resource Modeling 2020, 34, 1 .

AMA Style

Denys Yemshanov, Robert G. Haight, Rob Rempel, Ning Liu, Frank H. Koch. Protecting wildlife habitat in managed forest landscapes—How can network connectivity models help? Natural Resource Modeling. 2020; 34 (1):1.

Chicago/Turabian Style

Denys Yemshanov; Robert G. Haight; Rob Rempel; Ning Liu; Frank H. Koch. 2020. "Protecting wildlife habitat in managed forest landscapes—How can network connectivity models help?" Natural Resource Modeling 34, no. 1: 1.

Research article
Published: 21 May 2020 in Natural Resource Modeling
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ACS Style

Sabah Bushaj; I. Esra Büyüktahtakın; Denys Yemshanov; Robert G. Haight. Optimizing surveillance and management of emerald ash borer in urban environments. Natural Resource Modeling 2020, 34, 1 .

AMA Style

Sabah Bushaj, I. Esra Büyüktahtakın, Denys Yemshanov, Robert G. Haight. Optimizing surveillance and management of emerald ash borer in urban environments. Natural Resource Modeling. 2020; 34 (1):1.

Chicago/Turabian Style

Sabah Bushaj; I. Esra Büyüktahtakın; Denys Yemshanov; Robert G. Haight. 2020. "Optimizing surveillance and management of emerald ash borer in urban environments." Natural Resource Modeling 34, no. 1: 1.

Research article
Published: 23 August 2019 in PLoS ONE
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Detections of invasive species outbreaks are often followed by the removal of susceptible host organisms in order to slow the spread of the invading pest population. We propose the acceptance sampling approach for detection and optional removal of susceptible host trees to manage an outbreak of the emerald ash borer (EAB), a highly destructive forest pest, in Winnipeg, Canada. We compare the strategy with two common delimiting survey techniques that do not consider follow-up management actions such as host removal. Our results show that the management objective influences the survey strategy. The survey-only strategies maximized the capacity to detect new infestations and prioritized sites with high likelihood of being invaded. Comparatively, the surveys with subsequent host removal actions allocated most of the budget to sites where complete host removal would minimize the pest's ability to spread to uninvaded locations. Uncertainty about the pest's spread causes the host removal measures to cover a larger area in a uniform spatial pattern and extend to farther distances from already infested sites. If a decision maker is ambiguity-averse and strives to avoid the worst-case damages from the invasion, the optimal strategy is to survey more sites with high host densities and remove trees from sites at farther distances, where EAB arrivals may be uncertain, but could cause significant damage if not detected quickly. Accounting for the uncertainty about spread helps develop a more robust pest management strategy. The approach is generalizable and can support management programs for new pest incursions.

ACS Style

Denys Yemshanov; Robert G. Haight; Cuicui Chen; Ning Liu; Christian J. K. MacQuarrie; Frank H. Koch; Robert Venette; Krista Ryall. Managing biological invasions in urban environments with the acceptance sampling approach. PLoS ONE 2019, 14, e0220687 .

AMA Style

Denys Yemshanov, Robert G. Haight, Cuicui Chen, Ning Liu, Christian J. K. MacQuarrie, Frank H. Koch, Robert Venette, Krista Ryall. Managing biological invasions in urban environments with the acceptance sampling approach. PLoS ONE. 2019; 14 (8):e0220687.

Chicago/Turabian Style

Denys Yemshanov; Robert G. Haight; Cuicui Chen; Ning Liu; Christian J. K. MacQuarrie; Frank H. Koch; Robert Venette; Krista Ryall. 2019. "Managing biological invasions in urban environments with the acceptance sampling approach." PLoS ONE 14, no. 8: e0220687.

Journal article
Published: 03 May 2019 in Ecological Economics
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Surveillance programs to detect alien invasive pests seek to find them as soon as possible, but also to minimize the cost of damage from invasion. To examine the trade-offs between these objectives, we developed an economic model that allocates survey sites to minimize either the expected mitigation costs or the expected time until first detection of an invasive alien pest subject to a budget constraint on surveillance costs. We also examined strategies preferred by ambiguity-averse decision makers that minimize the expected and worst-case outcomes of each performance measure. We applied the model to the problem of detecting Asian longhorned beetle (Anoplophora glabripennis) in the Greater Toronto Area, Canada, one of the most harmful invasive alien insects in North America. When minimizing expected mitigation costs or expected time to detection, the trade-off between these survey objectives was small. Strategies that minimize the worst-case mitigation costs differed sharply and surveyed sites with high host densities using high sampling intensities whereas strategies that minimize the worst detection times surveyed sites across the entire area using low sampling intensities. Our results suggest that preferences for minimizing mitigation costs or time to detection are more consequential for ambiguity-averse managers than they are for risk-neutral decision-makers.

ACS Style

Denys Yemshanov; Robert G. Haight; Frank H. Koch; Robert C. Venette; Tom Swystun; Ronald Fournier; Mireille Marcotte; Yongguang Chen; Jean Turgeon. Optimizing surveillance strategies for early detection of invasive alien species. Ecological Economics 2019, 162, 87 -99.

AMA Style

Denys Yemshanov, Robert G. Haight, Frank H. Koch, Robert C. Venette, Tom Swystun, Ronald Fournier, Mireille Marcotte, Yongguang Chen, Jean Turgeon. Optimizing surveillance strategies for early detection of invasive alien species. Ecological Economics. 2019; 162 ():87-99.

Chicago/Turabian Style

Denys Yemshanov; Robert G. Haight; Frank H. Koch; Robert C. Venette; Tom Swystun; Ronald Fournier; Mireille Marcotte; Yongguang Chen; Jean Turgeon. 2019. "Optimizing surveillance strategies for early detection of invasive alien species." Ecological Economics 162, no. : 87-99.

Journal article
Published: 15 February 2019 in Biological Conservation
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Anthropogenic disturbances fragmenting wildlife habitat greatly contribute to extinction risk for many species. In western Canada, four decades of oil and gas exploration have created a network of seismic lines, which are linear disturbances where seismic equipment operates. Seismic lines cause habitat fragmentation and increase predator access to intact forest, leading to declines of some wildlife populations, particularly the threatened woodland caribou, Rangifer tarandus caribou. Restoration of forests within seismic lines is an important activity to reduce habitat fragmentation and recovery caribou. We present an optimization model with the objective of guiding landscape restoration strategies that maximize the area of connected habitat for a caribou population in a fragmented landscape. We use our model to find optimal strategies for seismic line restoration in the Cold Lake Area of Alberta, Canada, a 6726-km2 expanse of boreal forest that represents prime caribou habitat. We formulate mixed integer programming models that depict the landscape as a network of interconnected habitat patches. We develop and compare formulations that emphasize the population's local or long-distance access to habitat. Optimal restoration involves a mix of two strategies: the first establishes short-distance connections between forest patches with large areas of intact habitat and the second establishes corridors between areas with known species locations and large amounts of suitable habitat. Our approach reveals the trade-offs between these strategies and finds the optimal restoration solutions under a limited budget. The approach is generalizable and applicable to other regions and species sensitive to changes in landscape-level habitat connectivity.

ACS Style

Denys Yemshanov; Robert G. Haight; Frank H. Koch; Marc-André Parisien; Tom Swystun; Quinn Barber; A. Cole Burton; Salimur Choudhury; Ning Liu. Prioritizing restoration of fragmented landscapes for wildlife conservation: A graph-theoretic approach. Biological Conservation 2019, 232, 173 -186.

AMA Style

Denys Yemshanov, Robert G. Haight, Frank H. Koch, Marc-André Parisien, Tom Swystun, Quinn Barber, A. Cole Burton, Salimur Choudhury, Ning Liu. Prioritizing restoration of fragmented landscapes for wildlife conservation: A graph-theoretic approach. Biological Conservation. 2019; 232 ():173-186.

Chicago/Turabian Style

Denys Yemshanov; Robert G. Haight; Frank H. Koch; Marc-André Parisien; Tom Swystun; Quinn Barber; A. Cole Burton; Salimur Choudhury; Ning Liu. 2019. "Prioritizing restoration of fragmented landscapes for wildlife conservation: A graph-theoretic approach." Biological Conservation 232, no. : 173-186.

Journal article
Published: 17 March 2018 in Forest Ecology and Management
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Despite serving as invasion gateways for non-native forest pests, urban forests are less well understood than natural forests. For example, only a fraction of communities in the USA and Canada have completed urban forest inventories, and most have been limited to street trees; sample-based inventories that provide valid community-wide estimates of urban forest composition are much rarer. As a proof of concept, we devised a three-step approach to model urban tree distributions regionally using available street tree and whole-community inventory data. We illustrate the approach for three tree genera – ash (Fraxinus spp.), maple (Acer spp.), and oak (Quercus spp.) – that are hosts for high-profile insect pests. The objective of the first step was to estimate, for communities with only street tree inventories, the proportion of the community’s total basal area (BA) in each host genus. Utilizing data from communities with paired street tree and whole-community inventories, we applied polynomial regression to estimate whole-community BA proportion per genus as a function of a community’s street tree BA proportion and its geographic location. The objective of the second step was to estimate per-genus BA proportions for communities in our prediction region (eastern and central USA) with no urban forest inventory. We used stochastic gradient boosting to predict these proportions as a function of environmental and other variables. In the third step, we developed a generalized additive model for estimating the total BA of a community as a function of its canopy cover, geographic location, and area. We then combined the outputs from the second and third steps to estimate ash, maple, and oak BA for the nearly 24,000 communities in our prediction region. By merging these estimates with similar information on natural forests, we can provide more complete representations of host distributions for pest risk modeling, spread modeling, and other applications.

ACS Style

Frank H. Koch; Mark J. Ambrose; Denys Yemshanov; P. Eric Wiseman; F.D. Cowett. Modeling urban distributions of host trees for invasive forest insects in the eastern and central USA: A three-step approach using field inventory data. Forest Ecology and Management 2018, 417, 222 -236.

AMA Style

Frank H. Koch, Mark J. Ambrose, Denys Yemshanov, P. Eric Wiseman, F.D. Cowett. Modeling urban distributions of host trees for invasive forest insects in the eastern and central USA: A three-step approach using field inventory data. Forest Ecology and Management. 2018; 417 ():222-236.

Chicago/Turabian Style

Frank H. Koch; Mark J. Ambrose; Denys Yemshanov; P. Eric Wiseman; F.D. Cowett. 2018. "Modeling urban distributions of host trees for invasive forest insects in the eastern and central USA: A three-step approach using field inventory data." Forest Ecology and Management 417, no. : 222-236.

Journal article
Published: 08 February 2018 in Forests
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Burning forest biomass from renewable sources has been suggested as a viable strategy to help offset greenhouse gas (GHG) emissions in the energy generation sector. Energy facilities can, in principle, be retrofitted to produce a portion of their energy from biomass. However, supply uncertainties affect costs, and are an important impediment to widespread and sustained adoption of this strategy. In this paper, we describe a general approach to assess the cost of offsetting GHG emissions at co-generation facilities by replacing two common fossil fuels, coal and natural gas, with forest harvest residue biomass for heat and electricity production. We apply the approach to a Canadian case study that identifies the price of GHG offsets that could make the use of forest residue biomass feedstock attractive. Biomass supply costs were based on a geographical assessment of industrial harvest operations in Canadian forests, biomass extraction and transportation costs, and included representation of basic ecological sustainability and technical accessibility constraints. Sensitivity analyses suggest that biomass extraction costs have the largest impact on the costs of GHG emission offsets, followed by fossil fuel prices. In the context of other evaluations of mitigation strategies in the energy generation sector, such as afforestation or industrial carbon capture, this analysis suggests that the substitution of fossil fuels by forest residue biomass could be a viable and reasonably substantive short-term alternative under appropriate GHG emission pricing schemes.

ACS Style

Denys Yemshanov; Daniel W. McKenney; Emily Hope; Tony Lempriere. Renewable Energy from Forest Residues—How Greenhouse Gas Emission Offsets Can Make Fossil Fuel Substitution More Attractive. Forests 2018, 9, 79 .

AMA Style

Denys Yemshanov, Daniel W. McKenney, Emily Hope, Tony Lempriere. Renewable Energy from Forest Residues—How Greenhouse Gas Emission Offsets Can Make Fossil Fuel Substitution More Attractive. Forests. 2018; 9 (2):79.

Chicago/Turabian Style

Denys Yemshanov; Daniel W. McKenney; Emily Hope; Tony Lempriere. 2018. "Renewable Energy from Forest Residues—How Greenhouse Gas Emission Offsets Can Make Fossil Fuel Substitution More Attractive." Forests 9, no. 2: 79.

Research article
Published: 31 July 2017 in PLOS ONE
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Uncertainty about future spread of invasive organisms hinders planning of effective response measures. We present a two-stage scenario optimization model that accounts for uncertainty about the spread of an invader, and determines survey and eradication strategies that minimize the expected program cost subject to a safety rule for eradication success. The safety rule includes a risk standard for the desired probability of eradication in each invasion scenario. Because the risk standard may not be attainable in every scenario, the safety rule defines a minimum proportion of scenarios with successful eradication. We apply the model to the problem of allocating resources to survey and eradicate the Asian longhorned beetle (ALB, Anoplophora glabripennis) after its discovery in the Greater Toronto Area, Ontario, Canada. We use historical data on ALB spread to generate a set of plausible invasion scenarios that characterizes the uncertainty of the beetle’s extent. We use these scenarios in the model to find survey and tree removal strategies that minimize the expected program cost while satisfying the safety rule. We also identify strategies that reduce the risk of very high program costs. Our results reveal two alternative strategies: (i) delimiting surveys and subsequent tree removal based on the surveys' outcomes, or (ii) preventive host tree removal without referring to delimiting surveys. The second strategy is more likely to meet the stated objectives when the capacity to detect an invader is low or the aspirations to eradicate it are high. Our results provide practical guidelines to identify the best management strategy given aspirational targets for eradication and spending.

ACS Style

Denys Yemshanov; Robert G. Haight; Frank H. Koch; Robert Venette; Kala Studens; Ronald E. Fournier; Tom Swystun; Jean J. Turgeon. A safety rule approach to surveillance and eradication of biological invasions. PLOS ONE 2017, 12, e0181482 .

AMA Style

Denys Yemshanov, Robert G. Haight, Frank H. Koch, Robert Venette, Kala Studens, Ronald E. Fournier, Tom Swystun, Jean J. Turgeon. A safety rule approach to surveillance and eradication of biological invasions. PLOS ONE. 2017; 12 (7):e0181482.

Chicago/Turabian Style

Denys Yemshanov; Robert G. Haight; Frank H. Koch; Robert Venette; Kala Studens; Ronald E. Fournier; Tom Swystun; Jean J. Turgeon. 2017. "A safety rule approach to surveillance and eradication of biological invasions." PLOS ONE 12, no. 7: e0181482.

Journal article
Published: 01 May 2017 in Journal of Environmental Management
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Assessing risks of uncertain but potentially damaging events, such as environmental disturbances, disease outbreaks and pest invasions, is a key analytical step that informs subsequent decisions about how to respond to these events. We present a continuous risk measure that can be used to assess and prioritize environmental risks from uncertain data in a geographical domain. The metric is influenced by both the expected magnitude of risk and its uncertainty. We demonstrate the approach by assessing risks of human-mediated spread of Asian longhorned beetle (ALB, Anoplophora glabripennis) in Greater Toronto (Ontario, Canada). Information about the human-mediated spread of ALB through this urban environment to individual geographical locations is uncertain, so each location was characterized by a set of probabilistic rates of spread, derived in this case using a network model. We represented the sets of spread rates for the locations by their cumulative distribution functions (CDFs) and then, using the first-order stochastic dominance rule, found ordered non-dominant subsets of these CDFs, which we then used to define different classes of risk across the geographical domain, from high to low. Because each non-dominant subset was estimated with respect to all elements of the distribution, the uncertainty in the underlying data was factored into the delineation of the risk classes; essentially, fewer non-dominant subsets can be defined in portions of the full set where information is sparse. We then depicted each non-dominant subset as a point cloud, where points represented the CDF values of each subset element at specific sampling intervals. For each subset, we then defined a hypervolume bounded by the outermost convex frontier of that point cloud. This resulted in a collection of hypervolumes for every non-dominant subset that together serve as a continuous measure of risk, which may be more practically useful than averaging metrics or ordinal rank measures. Overall, the approach offers a rigorous depiction of risk in a geographical domain when the underlying estimates of risk for individual locations are represented by sets or distributions of uncertain estimates. Our hypervolume-based approach can be used to compare assessments made with different datasets and assumptions.

ACS Style

Denys Yemshanov; Frank H. Koch; Bo Lu; Ronald Fournier; Gericke Cook; Jean J. Turgeon. A new hypervolume approach for assessing environmental risks. Journal of Environmental Management 2017, 193, 188 -200.

AMA Style

Denys Yemshanov, Frank H. Koch, Bo Lu, Ronald Fournier, Gericke Cook, Jean J. Turgeon. A new hypervolume approach for assessing environmental risks. Journal of Environmental Management. 2017; 193 ():188-200.

Chicago/Turabian Style

Denys Yemshanov; Frank H. Koch; Bo Lu; Ronald Fournier; Gericke Cook; Jean J. Turgeon. 2017. "A new hypervolume approach for assessing environmental risks." Journal of Environmental Management 193, no. : 188-200.

Book chapter
Published: 01 January 2017 in Invasive Species
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ACS Style

Denys Yemshanov; Frank H. Koch; John W. Coulston; William D. Smith; Andrew P. Robinson; Terry Walshe; Mark A. Burgman; Mike Nunn. Mapping Risks and Impacts of Invasive Alien Species with Dynamic Simulation Models. Invasive Species 2017, 130 -151.

AMA Style

Denys Yemshanov, Frank H. Koch, John W. Coulston, William D. Smith, Andrew P. Robinson, Terry Walshe, Mark A. Burgman, Mike Nunn. Mapping Risks and Impacts of Invasive Alien Species with Dynamic Simulation Models. Invasive Species. 2017; ():130-151.

Chicago/Turabian Style

Denys Yemshanov; Frank H. Koch; John W. Coulston; William D. Smith; Andrew P. Robinson; Terry Walshe; Mark A. Burgman; Mike Nunn. 2017. "Mapping Risks and Impacts of Invasive Alien Species with Dynamic Simulation Models." Invasive Species , no. : 130-151.

Journal article
Published: 22 December 2016 in Ecological Economics
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Uncertainty about future outcomes of invasions is a major hurdle in the planning of invasive species management programs. We present a scenario optimization model that incorporates uncertainty about the spread of an invasive species and allocates survey and eradication measures to minimize the number of infested or potentially infested host plants on the landscape. We demonstrate the approach by allocating surveys outside the quarantine area established following the discovery of the Asian longhorned beetle (ALB) in the Greater Toronto Area (GTA), Ontario, Canada. We use historical data on ALB spread to generate a set of invasion scenarios that characterizes the uncertainty of the pest's extent in the GTA. We then use these scenarios to find allocations of surveys and tree removals aimed at managing the spread of the pest in the GTA. It is optimal to spend approximately one-fifth of the budget on surveys and the rest on tree removal. Optimal solutions do not always select sites with the greatest propagule pressure, but in some cases focus on sites with moderate likelihoods of ALB arrival and low host densities. Our approach is generalizable and helps support decisions regarding control of invasive species when knowledge about a species' spread is uncertain.

ACS Style

Denys Yemshanov; Robert G. Haight; Frank H. Koch; Bo Lu; Robert Venette; Ronald Fournier; Jean Turgeon. Robust Surveillance and Control of Invasive Species Using a Scenario Optimization Approach. Ecological Economics 2016, 133, 86 -98.

AMA Style

Denys Yemshanov, Robert G. Haight, Frank H. Koch, Bo Lu, Robert Venette, Ronald Fournier, Jean Turgeon. Robust Surveillance and Control of Invasive Species Using a Scenario Optimization Approach. Ecological Economics. 2016; 133 ():86-98.

Chicago/Turabian Style

Denys Yemshanov; Robert G. Haight; Frank H. Koch; Bo Lu; Robert Venette; Ronald Fournier; Jean Turgeon. 2016. "Robust Surveillance and Control of Invasive Species Using a Scenario Optimization Approach." Ecological Economics 133, no. : 86-98.

Biodiversity research
Published: 21 August 2015 in Diversity and Distributions
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Aim We address the problem of geographically allocating scarce survey resources to detect pests in their pathways of introduction given information about their likelihood of movement between origins and destinations. We introduce a model for selecting destination sites for survey that departs from the aim of reducing propagule pressure (PP) in pest destinations and instead aims to increase monitoring of pest origins. The model is a maximum expected coverage problem (MECP), which maximizes the expected number of origins that are covered by the survey system, where an origin is covered if at least one of its transmission pathways connects to a surveyed destination. For comparison, we present two models that aim to reduce PP in destination sites. One model maximizes the expected number of transmission pathways that are covered by survey locations and the other maximizes the expected number of survey locations that have one or more pest introductions. Location United States, Canada. Methods We demonstrate the models by analysing the human‐mediated spread of the emerald ash borer (Agrilus planipennis Fairmaire), a major pest of ash trees in North America, by visitors to campgrounds in central Canada and the US Midwest. The models incorporate estimates of spread rates from a network of campers travelling from approximately 6500 invaded domains to 266 uninvaded campgrounds in three Canadian provinces (Ontario, Quebec and Manitoba) and three US states (Michigan, Minnesota and Wisconsin). Results The MECP and PP‐based model solutions agreed for large surveillance budgets but exhibited differences when the budgets were small. These results stem from differences between the coverage‐based objective in MECP and the PP‐based metrics in the PP models. Main conclusions Our comparison of MECP and PP‐based models reveals the trade‐offs between objectives. Overall, the MECP is generic and can be adapted to survey species that are spread via other human‐mediated vectors.

ACS Style

Denys Yemshanov; Robert G. Haight; Frank Koch; Bo Lu; Robert Venette; D. Barry Lyons; Taylor Scarr; Krista Ryall. Optimal allocation of invasive species surveillance with the maximum expected coverage concept. Diversity and Distributions 2015, 21, 1349 -1359.

AMA Style

Denys Yemshanov, Robert G. Haight, Frank Koch, Bo Lu, Robert Venette, D. Barry Lyons, Taylor Scarr, Krista Ryall. Optimal allocation of invasive species surveillance with the maximum expected coverage concept. Diversity and Distributions. 2015; 21 (11):1349-1359.

Chicago/Turabian Style

Denys Yemshanov; Robert G. Haight; Frank Koch; Bo Lu; Robert Venette; D. Barry Lyons; Taylor Scarr; Krista Ryall. 2015. "Optimal allocation of invasive species surveillance with the maximum expected coverage concept." Diversity and Distributions 21, no. 11: 1349-1359.

Journal article
Published: 01 July 2015 in Ecological Indicators
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Denys Yemshanov; Frank H. Koch; Kurt H. Riitters; Brian McConkey; Ted Huffman; Stephen Smith. Assessing land clearing potential in the Canadian agriculture–forestry interface with a multi-attribute frontier approach. Ecological Indicators 2015, 54, 71 -81.

AMA Style

Denys Yemshanov, Frank H. Koch, Kurt H. Riitters, Brian McConkey, Ted Huffman, Stephen Smith. Assessing land clearing potential in the Canadian agriculture–forestry interface with a multi-attribute frontier approach. Ecological Indicators. 2015; 54 ():71-81.

Chicago/Turabian Style

Denys Yemshanov; Frank H. Koch; Kurt H. Riitters; Brian McConkey; Ted Huffman; Stephen Smith. 2015. "Assessing land clearing potential in the Canadian agriculture–forestry interface with a multi-attribute frontier approach." Ecological Indicators 54, no. : 71-81.

Journal article
Published: 01 October 2014 in Biomass and Bioenergy
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Denys Yemshanov; Daniel W. McKenney; Saul Fraleigh; Brian McConkey; Ted Huffman; Stephen Smith. Cost estimates of post harvest forest biomass supply for Canada. Biomass and Bioenergy 2014, 69, 80 -94.

AMA Style

Denys Yemshanov, Daniel W. McKenney, Saul Fraleigh, Brian McConkey, Ted Huffman, Stephen Smith. Cost estimates of post harvest forest biomass supply for Canada. Biomass and Bioenergy. 2014; 69 ():80-94.

Chicago/Turabian Style

Denys Yemshanov; Daniel W. McKenney; Saul Fraleigh; Brian McConkey; Ted Huffman; Stephen Smith. 2014. "Cost estimates of post harvest forest biomass supply for Canada." Biomass and Bioenergy 69, no. : 80-94.

Journal article
Published: 20 May 2014 in Ecological Economics
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In this study we demonstrate how the notion of diversification can be used in broad-scale resource allocation for surveillance of invasive species. We consider the problem of short-term surveillance for an invasive species in a geographical environment. We find the optimal allocation of surveillance resources among multiple geographical subdivisions via application of a classical portfolio framework, which allocates investments among multiple financial asset types with uncertain returns in a portfolio that maximizes the performance and, by meeting the desired diversification targets, protects against errors in estimating the portfolio's performance. We illustrate the approach with a case study that applies a spatial transmission model to assess the risk of spread of the emerald ash borer (EAB), a significant pest in North America, with infested firewood that may be carried by visitors to campground facilities in central Canada. Adding the diversification objective yields an expected survey performance that is comparable with undiversified optimal allocation, but more importantly, makes the geographical distribution of survey priorities less subject to possible errors in the spread rate estimates. Overall, diversification of pest surveillance can be viewed as a viable short-term strategy for hedging against uncertainty in expert- and model-based assessments of pest invasion risk.

ACS Style

Denys Yemshanov; Frank H. Koch; Bo Lu; D. Barry Lyons; Jeffrey P. Prestemon; Taylor Scarr; Klaus Koehler. There is no silver bullet: The value of diversification in planning invasive species surveillance. Ecological Economics 2014, 104, 61 -72.

AMA Style

Denys Yemshanov, Frank H. Koch, Bo Lu, D. Barry Lyons, Jeffrey P. Prestemon, Taylor Scarr, Klaus Koehler. There is no silver bullet: The value of diversification in planning invasive species surveillance. Ecological Economics. 2014; 104 ():61-72.

Chicago/Turabian Style

Denys Yemshanov; Frank H. Koch; Bo Lu; D. Barry Lyons; Jeffrey P. Prestemon; Taylor Scarr; Klaus Koehler. 2014. "There is no silver bullet: The value of diversification in planning invasive species surveillance." Ecological Economics 104, no. : 61-72.

Evaluation study
Published: 01 November 2013 in Journal of Environmental Management
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Long-distance introductions of alien species are often driven by socioeconomic factors, such that conventional "biological" invasion models may not be capable of estimating spread fully and reliably. In this study, we demonstrate a new technique for assessing and reconstructing human-mediated pathways of alien forest species entries to major settlements in Canada via commercial road transportation and domestic trade. We undertook our analysis in three steps. First, we used existing data on movement of commodities associated with bark- and wood-boring forest pests to build a probabilistic model of how the organisms may be moved from one location to another through a transportation network. We then used this model to generate multiple sets of predictions of species arrival rates at every location in the transportation network, and to identify the locations with the highest likelihood of new incursions. Finally, we evaluated the sensitivity of the species arrival rates to uncertainty in key model assumptions by testing the impact of additive and multiplicative errors (by respectively adding a uniform random variate or symmetric variation bounds to the arrival rate values) on the probabilities of pest transmission from one location to another, as well as the impact of the removal of one or more nodes and all connecting links to other nodes from the underlying transportation network. Overall, the identification of potential pest arrival hotspots is moderately robust to uncertainties in key modeling assumptions. Large urban areas and major border crossings that have the highest predicted species arrival rates have the lowest sensitivities to uncertainty in the pest transmission potential and to random changes in the structure of the transportation network. The roadside survey data appears to be sufficient to delineate major hubs and hotspots where pests are likely to arrive from other locations in the network via commercial truck transport. However, "pass-through" locations with few incoming and outgoing routes can be identified with lower precision. The arrival rates of alien forest pests appear to be highly sensitive to additive errors. Surprisingly, the impact of random changes in the structure of the transportation network was relatively low.

ACS Style

Denys Yemshanov; Frank H. Koch; Mark J. Ducey; Marty Siltanen; Kirsty Wilson; Klaus Koehler. Exploring critical uncertainties in pathway assessments of human-assisted introductions of alien forest species in Canada. Journal of Environmental Management 2013, 129, 173 -182.

AMA Style

Denys Yemshanov, Frank H. Koch, Mark J. Ducey, Marty Siltanen, Kirsty Wilson, Klaus Koehler. Exploring critical uncertainties in pathway assessments of human-assisted introductions of alien forest species in Canada. Journal of Environmental Management. 2013; 129 ():173-182.

Chicago/Turabian Style

Denys Yemshanov; Frank H. Koch; Mark J. Ducey; Marty Siltanen; Kirsty Wilson; Klaus Koehler. 2013. "Exploring critical uncertainties in pathway assessments of human-assisted introductions of alien forest species in Canada." Journal of Environmental Management 129, no. : 173-182.