Valuation of socioeconomic and environmental outcomes of forest residue management : a stated preference approach in Tasmania, Australia

<p dir="ltr">The overconsumption of fossil fuels and consequent climate change concerns have significantly highlighted global attention towards renewable energy sources. Forest residues, the byproducts of forest management and timber harvesting, have emerged as a potential renewable energy source, and their harvest may both reduce the need to burn residues and reduce the risk of wildfires with consequent reductions in woodsmoke and improvements in human health. Nevertheless, while harvesting forest residues for energy production has social and economic benefits, harvesting may interfere with some important forest ecosystem services, having a detrimental impact on soil nutrient levels and biodiversity. Consequently, policies need to be developed to balance potential conflicts and maximise the (net) benefits of woody biomass mobilisation for energy production and smoke reduction. This requires information about potential trade-offs between the outcomes associated with managing forest residues for energy production compared to the conventional management option where forest residues are either left or burnt on-site. <br>Forest residues can be managed to mitigate wildfires and to optimise the utilisation of biomass for energy production, yet forest residues are an understudied aspect of forest management practices. Despite a growing body of research that addresses biophysical aspects of forest residue harvesting, a notable gap exists in research that explicitly values socioeconomic and environmental outcomes of forest residue management. To address this gap, we undertake research in Tasmania, Australia, where there is a growing concern about the potential environmental and economic impacts of unmanaged forest residues: critically, in this state, the biomass from wood processing residues (primarily sawdust and off-cuts from sawmills), harvesting residues, and low-quality timber is estimated at 3.3 million tonnes per year, with the potential to produce up to 30% of Tasmanian's total energy supply. This makes the region an ideal place to improve our understanding of some of the socioeconomic and environmental implications of forest residue management, generating insights that could have broader relevance elsewhere in the world. <br>The overall objective of this research is to value some of the socioeconomic and environmental outcomes of forest residue management in Tasmania, Australia, and work is undertaken through four interconnected papers. The first paper focuses on understanding public preferences and Willingness to Pay (WTP) for forest residue management outcomes using a Discrete Choice Experiment (DCE). The choices that are presented to respondents are associated with a hypothetical policy that describes changes in forest residue management practices impacting invertebrate species, smoke emissions, regional employment opportunities and price/policy costs (i.e., council rates or housing rents). The estimated Error-Component Mixed Logit (EC-MXL) shows that, on average, respondents were willing to pay AUD 34, AUD 29, and AUD 14 per year, respectively, for residue management practices that reduce smoke emissions, increase the abundance and diversity of invertebrate species, and create employment. The empirical evidence highlights a marked public inclination to support sustainable forest residue management practices compared to current residue management, where residues are either left or burnt on-site.<br>The second paper advances the analysis by examining the intricate relationship between environmental value orientations and WTP for forest residue management outcomes using a Hybrid Choice Model (HCM). Results show that respondents with biocentric leaning have significantly higher WTP for forest residue management outcomes compared to those with anthropocentric orientations. This suggests that moral and ethical considerations play a crucial role in shaping individual choices in support of environmental policies. In addition, our findings indicate that older persons, female respondents, individuals with a university degree and above, individuals in the high-income group, those who are members of environmental organisations, and those living in semi-urban and major urban areas were more likely than others to have relatively biocentric leaning. By extension, thus, they are more likely to support forest residue management practices that generate social and environmental outcomes (specifically those relating to biodiversity and smoke reduction) than practices that focus predominantly on economic outcomes (e.g., employment). <br>The third paper used data collected from the contingent valuation survey to estimate the Value of a Statistical Life (VSL) from biomass smoke emission reduction using parametric and non-parametric models. The associated non-parametric (lower bound) estimate of the VSL for death risk reduction from smoke emission was AUD 928,000. The parametric estimation derived from a Seemingly Unrelated Bivariate Probit (SUBP) model was AUD 1.1 million. The empirical findings could inform a cost-benefit analysis of environmental policies that aim to reduce the smoke-induced health impacts of wood heaters, planned burning, and/or wildfire. Our estimates could also be used to inform policy or management in other regions grappling with landscape fires and/or wood smoke problems after making contextual adjustments for influencing factors.<br>The fourth paper advances the VSL analysis further by exploring the way in which the health risk attitudes of respondent’s effect on WTP to reduce the mortality risk due to biomass smoke emission. The impact of environmental hazards like biomass smoke disproportionately affects individuals’ health, which raises a question of health inequity in evaluating policy interventions. Hence, policy analysis needs to consider individual heterogeneity, since differences in individual health risk attitudes may lead to differences in health investments. We measured health risk attitudes using a seven-point Likert scale consisting of 13 items, which predicts an individual’s propensity to engage in hazardous health-related choices pertaining to illness prevention, treatment, and overall health behaviour. Both latent class analysis and cluster analysis were used to characterise respondents according to their health risk attitude. Based on the latent class analysis, risk averse individuals are those with a higher education, higher income, being male and or older will increase the probability of being risk-seeking. Our findings indicate that individuals who exhibit risk aversion towards their health tend to possess a lower VSL than those who exhibit risk-seeking behaviours. This could be because risk-averse individuals invest sufficient resources to reduce health risks. <br>Methodologically, the thesis demonstrates the efficacy of combining a DCE and CVM for a more nuanced values for environmental goods and services. Firstly, it shows that the combination of DCE and CVM provides a comprehensive and more nuanced analysis of environmental goods and services. It introduces the use of context-based scales to elicit environmental value orientations and health risk attitudes. These are tailored to the specific environmental and health contexts under the study, thus ensuring that the assessment of public attitudes is more accurate and relevant compared to the traditional generic scales. Furthermore, the study explores the theoretical relationship between health risk attitude and VSL and empirically tests this relationship, adding new insights to the literature. <br>Collectively, this thesis offers a holistic view of forest residue management, encompassing environmental, economic and health dimensions. This comprehensive analysis is vital for formulating strategies to manage forest residues that are not only environmentally sustainable but also socially and demographically aligned. For example, the fact that respondents place a balanced value on invertebrate species and smoke emission reduction suggests valuing both the conservation of natural habits and the reduction of air pollution. This indicates that Tasmania could benefit from adopting forest residue management policies like those in European countries such as Finland and Sweden, where there is a balanced focus on both preserving biodiversity and improving air quality. The finding highlights the importance of considering individual heterogeneity and context-specific factors when addressing environmental issues and uniquely blends insights from multiple disciplines to develop analytical methods to do so. Empirical results highlight that the management of forest residues to control smoke emissions is particularly crucial for elderly individuals and areas prone to wildfires, such as the southeastern and northeastern regions of Tasmania. The thesis emphasises the importance of considering individual value orientations and health risk attitudes in for the formulation of effective forest residue management policies. The results are essential not only for Tasmania but also for other regions with similar environmental challenges, providing a framework for policy formulation that includes diverse public preferences and moral, ethical and health considerations of the public.</p>