Landowner Functional Types to Characterize Response to Forest Insects

Abstract

Forest insects and pathogens (FIPs) play an important role in the complex interactions between woodland owners and the ecosystems they manage. Understanding the specifics of woodland owner decision-making with regard to trees impacted by FIPs can facilitate projections of future forest conditions and insect spread. Our first objective is to: (i) characterize agent functional types (AFTs) of New England family forest owners (FFOs) using a set of contingent behavior questions contained in a mail survey of FFOs concerning response to FIPs. We establish AFTs as a form of dimension reduction, effectively assigning individual FFOs to particular decision-making classes, each with distinct probabilities of behavior with respect to the harvest of impacted trees. Our second objective is to: (ii) model AFT membership to predict the distribution of AFTs across the landscape. Predictors are chosen from a set of survey, geographic, and demographic features. Accomplishing (i) establishes three functional classes of landowners: ‘cutters’ (46% of respondents; highly likely to cut timber impacted by FIPs), ‘responsive’ cutters (42% of respondents; sensitive to pest severity), and ‘non-cutters’ (12% of respondents; highly unlikely to cut). Fulfilling (ii) provides a high-resolution probability surface of AFTs across the landscape, delivering key input for simulation models of forest and land cover change in New England. Predictors in our best model of AFT membership include parcel size (hectares of forest), region, and town-level forested fraction.

Potential Impacts of Insect-Induced Harvests in the Mixed Forests of New England

“…We also assumed that EAB was present in populations throughout the study area at high enough densities to initiate management responses throughout the watershed (at its current rate of spread, this assumption will likely be met within one decade) [26]. We used the models presented in Holt et al [17] and Appendix B to assign agent functional types to all FFO parcels greater than 4 ha in size in the Connecticut River Watershed (Figure 2a). As described in Holt et al [17], larger parcels (>20 ha) or any parcels in NH (as identified using a classification and regression tree method with states as a possible predictor variable) were more likely to end up in a Forests 2020, 11, 498 6 of 18 "cutter" type class (i.e., Cutter or Responsive Cutter types) with larger amounts of forested land on their parcel.…”

“…Respondents were given four scenarios of a forest insect arrival and tree mortality and responded whether they would harvest in each scenario and provided a measure of certainty in their answer (Appendix A). The respondents of the survey were classified into three categories: (1) Cutters (46% of respondents)-those that responded they would harvest for all four insect scenarios; (2) Responsive Cutters (42%)-those that responded they would harvest in some of the scenarios presented; and (3) Non-cutters (12%)-those that would not harvest in any of the scenarios presented [7,17]. These categories of respondents served as the basis for three agent functional types (Cutters, Responsive Cutters, and Non-cutters) that we characterized using the different landowner responses to the presence of a generic forest insect [17] (Appendix B).…”

“…The respondents of the survey were classified into three categories: (1) Cutters (46% of respondents)-those that responded they would harvest for all four insect scenarios; (2) Responsive Cutters (42%)-those that responded they would harvest in some of the scenarios presented; and (3) Non-cutters (12%)-those that would not harvest in any of the scenarios presented [7,17]. These categories of respondents served as the basis for three agent functional types (Cutters, Responsive Cutters, and Non-cutters) that we characterized using the different landowner responses to the presence of a generic forest insect [17] (Appendix B). We then used geographic land cover and demographic data at the parcel and town level to create a predictive model for these agent functional types [17] (Appendix B).…”

“…These categories of respondents served as the basis for three agent functional types (Cutters, Responsive Cutters, and Non-cutters) that we characterized using the different landowner responses to the presence of a generic forest insect [17] (Appendix B). We then used geographic land cover and demographic data at the parcel and town level to create a predictive model for these agent functional types [17] (Appendix B). Predicting agent functional types for FFO parcels in the Connecticut River Watershed did not require knowing specific forest insect invasion characteristics; however, we found that the likelihood of harvesting in response to a forest insect for each parcel in an agent functional type relied on specific insect characteristics [17] (Appendix B).…”

“…We then used geographic land cover and demographic data at the parcel and town level to create a predictive model for these agent functional types [17] (Appendix B). Predicting agent functional types for FFO parcels in the Connecticut River Watershed did not require knowing specific forest insect invasion characteristics; however, we found that the likelihood of harvesting in response to a forest insect for each parcel in an agent functional type relied on specific insect characteristics [17] (Appendix B). Here, we apply our knowledge of FFO response to forest insects and the developed agent functional types to the specific case of emerald ash borer (EAB) to determine the potential direct and indirect impacts on the mixed forests of the Connecticut River Watershed.…”