Progress 01/01/24 to 12/31/24
Outputs
Target Audience:The target audience for this project includes diverse stakeholders throughout the northeast region who are interested in the syrup industry, including syrup producers, woodland owners, and farmers, as well as consumers and the general public. Given the important cultural, ecological, economic, and historical importance of the syrup industry in New England, this project has the potential to attract broad interest in the region.The target audience for this project includes diverse stakeholders throughout the northeast region who are interested in the syrup industry, including syrup producers, woodland owners, and farmers, as well as consumers and the general public. Given the important cultural, ecological, economic, and historical importance of the syrup industry in New England, this project has the potential to attract broad interest in the region. Changes/Problems:The amount of time required to fell and transport the study trees, process them into cross-sectional stem cookies, and prepare them for analysis was substantially greater than we had originally anticipated. Because some of the study sites were located at remote sites and on difficult terrain, transporting the felled trees was especially challenging. Fortunately, by the end of this reporting period, all wood cookies had been transported to campus, and are currently being planed, sanded, photographed, and analyzed to determine the area and volume of nonconductive wood columns for each sample tree. Several changes were made to the survey implementation strategy in response to unanticipated challenges. First, after launching the online survey, a bot attack occurred when the public survey link was shared in a state-level Facebook group, leading to a high volume of invalid responses. To address this, we discontinued the use of social media and other public channels for distribution. Instead, we implemented a more secure protocol by generating individualized survey links and requiring respondents to enter a unique access code to ensure authenticity. Second, the initial sample obtained from a data company and through state extension personnel was smaller than expected and yielded a low response rate. To expand the sample size, we collected additional producer addresses from maple syrup association websites and shifted toward mail-based distribution. Third, to improve the response rate, we removed the email sign-up step from the survey and relied on access codes for entry. Importantly, we shifted from an online survey to a paper mail survey. These adjustments collectively enhanced the reliability of the data and ensured that responses were collected from verified producers within the target population. What opportunities for training and professional development has the project provided? A one-week intensive training course in CRBasic programming language for use with Campbell CR1000 dataloggers (Campbell Scientific, Inc., Logan, UT) was held by PhD student David Moore. This knowledge was gained as part of the AFRI project and was critical for obtaining and processing the sap-flow data (https://github.com/davidblakneymoore/Sap-Flow-Stuff). Seven other UNH graduate students participated in the course. Topics ranged from electrical engineering to datalogger form and function to programming. Three vastly different types of sensors (thermocouples, pressure sensors, and moisture content sensors), all of which were used in this project, were used as examples during the course. Five technicians and graduate students gained skills in basic chainsaw use, safety and maintenance, and in operating a chainsaw winch as part of harvesting logs for the study. One graduate student (David Moore) learned how to operate a differential scanning calorimeter. One technician and a graduate student were trained in tree climbing using the single-rope technique. David Moore conducted informal training with approximately 25 syrup producers and potential syrup producers on best management practices for harvesting sap and producing syrup from the 7 study species. One lead graduate student (Yizun Yan) received hands-on training in survey design and data collection. This included developing a discrete choice experiment with hypotheses based on a dynamic optimization model of optimal forest diversification, applying Bayesian efficient design to construct choice sets, and conducting in-person pilot testing with producers at the 2023 International Maple Syrup Conference. Additional training involved building a national database of maple syrup producers using association directories and SIC codes, which supported a mixed-mode survey approach through mail and email outreach. Training in data analysis focused on discrete choice modeling, including conditional logit, mixed logit, and latent class models. The student learned to test theory-driven hypotheses and analyze preference heterogeneity based on income reliance, risk attitudes, and time preferences. These experiences strengthened skills in empirical modeling, field survey implementation, and applied environmental and resource economics. One graduate student and an undergraduate research assistant collaborated to build a database of maple syrup business addresses. This involved collecting and cleaning producer contact information from the maple syrup association website among different states. The process provided practical training in data collection and management and offered both researchers valuable experience in preparing a contact database for survey implementation. How have the results been disseminated to communities of interest?Syrup producers and syrup researchers were reached through informal conversations with PhD student David Moore at the 2024 North American Maple Syrup Conference in Portland, ME, from October 21st to 24th. Syrup producers were also reached through Moore's oral presentation on winter sap flow dynamics at the annual meeting of the Maple Syrup Producers Association of Connecticut on November 9th, 2024, in Hebron, CT, which reached nearly 100 syrup producers from across the state of Connecticut. Syrup consumers were reached via a Boston Globe article ('Move over maple? With climate change, new interest in tapping other trees for syrup') from March 19th, 2024. This article, which was based on an interview with PhD Moore, allowed the topics explored in this project to reach a very broad audience of consumers, which is a crucial step in building markets for other types of syrups. Syrup consumers were also reached via a taste test hosted by the University of New Hampshire's College of Life Sciences and Agriculture on October 18th, 2024, during which Moore shared syrup samples produced from non-maple tree species that were the focus of this project. Other researchers in the fields of plant biology and agriculture also participated in this event. Maple syrup producers were reached through in-person interactions during the 2023 International Maple Syrup Conference, held in Sturbridge, Massachusetts, from October 25-28. This national event brought together hundreds of producers from the U.S. and Canada. As part of the conference, the research team conducted pilot testing of the survey instrument and held informal conversations with producers to introduce the forest diversification project. These conversations provided valuable feedback on producer concerns, motivations, and barriers related to diversification. Additional outreach was conducted by contacting extension personnel across multiple U.S. states, who assisted with the distribution of the survey through email lists and newsletters. These collaborations broadened the geographic reach of the project and supported data collection efforts. Importantly, this approach allows the research team to generate summary statistics and comparative insights by state, providing more targeted information for regional policy and outreach. Preliminary findings were presented at the 2024 W5133 Workshop on Economic Valuation and Management of Natural Resources on Public and Private Lands. This workshop provided an opportunity to share early results on maple syrup producers' preferences for diversification and to receive feedback on the choice experiment design and modeling framework from researchers focused on landowner behavior and conservation incentives. Results were also shared at the 2024 Agricultural and Applied Economics Association (AAEA) Annual Meeting. The presentation focused on the tradeoffs producers face between short-term yield loss and long-term climate resilience, and facilitated valuable discussion with researchers working on environmental policy, ecosystem services, and discrete choice modeling. What do you plan to do during the next reporting period to accomplish the goals?During 2025, we will process all of the wood cookies by planing, sanding, and photographing them. Each cookie will then be analyzed using ImageJ software to quantify the cross-sectional area of compartmentalized tissue for each slice and estimate the total volume and height of the nonconductive wood columns around tap holes. Furthermore, we will estimate growth rates using tree rings, and these growth rates will be compared with nonconductive wood column sizes to assess the long-term sustainability of tapping for the 7 study species. For example, if the basal area increment exceeds the maximum cross-sectional area of the nonconductive wood column, this would suggest that tapping is sustainable for a particular species. Follow-up studies should quantify growth rates of these study species for both tapped and untapped scenarios (and for a wide variety of tap hole sizes), to further refine these assessments of tapping sustainability. Also, during 2025, we will perform chemical analyses on all our sap and syrup samples from all study species from both 2022 and 2023. These analyses will include differential scanning calorimetry to identify the freezing points of the sap samples and both ultra-high-performance high resolution liquid chromatography-tandem mass spectrophotometry and nuclear magnetic resonance spectroscopy to identify molecules found in sap and syrup samples. We have sap and syrup samples from all 7 study species and for black walnut (with the exception of syrup for speckled alder). We will perform an analysis to understand the potential tradeoffs between carbon stocks, sawtimber, and syrup production, leveraging the publicly available Forest Inventory and Analysis data set. We will compare the potential for sawtimber production, carbon assimilation, and syrup production for stands of different forest compositions (for all different types of stands that include a reasonable proportion of our study species). These tradeoffs will take into account economic data collected during this project from the consumer preference analysis that was completed in 2024. Results will be used to develop guidelines to landowners, land managers, syrup producers, and policymakers about how to optimally use forested lands for diverse benefits, including syrup production from diverse tree species. Finally, during 2025, we will analyze and synthesize all the data and share it broadly through scientific publications, cooperative extension websites and outreach activities, professional presentations, webinars, and other media sources. During 2025, we will complete the full-scale data collection, with survey responses expected by April. Upon finalizing the dataset, we will estimate mixed logit and WTA-space models to quantify producers' willingness to accept payments under different program designs and to examine preference heterogeneity across producer characteristics. A central objective of the upcoming analysis is to evaluate the impact of the climate information treatment embedded in the choice experiment. Specifically, we will assess whether providing region-specific projections of future syrup production under the RCP 8.5 climate scenario influences producers' willingness to adopt forest diversification. The experimental design enables both between-subject comparisons (treatment vs. control) and within-subject comparisons (pre- vs. post-treatment), allowing us to isolate the effect of climate information on stated preferences. We hypothesize that the information treatment will influence producers' willingness to diversify differently across regions based on their climatic projections and the economic importance of their forests, but that the economic importance will matter more than the magnitude of climatic impact. While the Midwest is projected to face more severe impacts, the Northeast currently accounts for a larger share of total production. We will empirically test this hypothesis by estimating the causal effect of region-specific climate impact information on willingness to invest in climate resilience through diversification. In addition, we will simulate alternative policy scenarios to evaluate how varying payment levels and program attributes influence adoption rates. Collectively, these efforts will provide policy-relevant insights for designing targeted and effective incentive programs to support maple forest diversification as a climate adaptation strategy.
Impacts
What was accomplished under these goals?
Objective #1. Patterns and drivers of dormant season sap flow. To determine the patterns and drivers of winter-dormant-season sap flow in each potential syrup-producing species, in 2024 we continued data collection using sap-flow, wood-temperature, stem-pressure, and wood-moisture-content sensors in the same positions (just above the root flare at ground level, at breast height, and in the upper canopy) on the same study trees (3 trees of each of the 7 species). Sap flow and wood moisture content were measured only at breast height, but stem pressure and wood temperature were measured at all three heights. These measurements were taken throughout winter dormancy at 15-min intervals. To determine other physiological factors relevant to sap collection, we collected xylem sap osmolality measurements at regular intervals (at least monthly) from all study trees and stem positions. These osmolality measurements will be used to determine the presence of axial osmotic gradients during winter dormancy and their potential role in driving sap flow or sap pressurization and under what environmental conditions. We also measured xylem sap supercooling in situ using wood temperature sensors at high-resolution, 1-second intervals. Supercooling exotherms (i.e., when temperatures drop below the freezing point but then increase slightly around (or just below) 0 ? C (Fig. 1)) indicate the temperatures at which sap freezes and thaws for each study species. These data will be compared to differential scanning calorimetry measurements to derive the averages, variances, and ranges of the freezing points. During 2024, we also received training on how to use the differential scanning calorimeter, which we will use in 2025 to measure the freezing points of all sap samples, further advancing knowledge about the drivers of sap flow and pressurization during winter dormancy. To assess patterns of nonconductive wood formation in response to tapping, between September and December of 2024, we felled trees that had been tapped in 2022 and 2023, including: 4 American beeches (Fagus grandifolia), 5 sugar maples (Acer saccharum), 6 paper birches (Betula papyrifera), 14 speckled alders (Alnus incana), 7 American hophornbeams (Ostrya virginiana), 7 American sycamores (Platanus occidentalis), and 5 American basswoods (Tilia americana). Cross-sectional stem "cookies" were then generated every 2 inches above and below tap holes until the columns of nonconductive wood associated with these tap holes disappeared. Since trees were tapped twice (in 2022 and 2023), each tree will provide information about two nonconductive wood columns. These cookies are in the process of being planed and sanded. Objective #2. Nutritional qualities and chemical properties. To evaluate the nutritional quality and chemical properties of novel tree saps and syrups, we tapped one additional species, black walnut (Juglans nigra), in 2024, to complement previous sap collection efforts on the original 7 study species, using the same sap harvesting and syrup production techniques. Black walnut was added due to its economic importance and potentially valuable syrup. These samples are in the process of being analyzed for phytochemical properties. Objective #3. Consumer preferences and willingness to pay; willingness of syrup producers to adopt To assess syrup producers' willingness to adopt forest diversification under a payment for ecosystem services (PES) program, we developed and implemented a discrete choice experiment (CE) that captures the key trade-offs influencing adoption decisions.The CE was built around seven key attributes, including diversification intensity, syrup yield reduction, resilience benefits, peer adoption rate, equipment costs, contract length, and annual payments. These attributes capture the economic and ecological trade-offs producers face when considering diversification. In 2024, we successfully completed pilot data collection and conducted preliminary analysis using conditional and mixed logit models. Findings from the pilot phase of our survey show that a decline in maple yield as a result of diversification significantly decreases their likelihood of diversification adoption. We find that preferences for diversification intensity and contract length are nonlinear, with producers favoring moderate levels of diversification. Producers show a preference for either short-term contracts (5 years), which provide flexibility by allowing frequent adjustments to management strategies without the constraints of long-term commitments, or much longer contracts (15 years), which is more consistent with the timeframe needed to realize the slow-maturing environmental benefits of increased resilience. We also find that higher rates of diversification adoption by peers reduce the likelihood of own diversification efforts, possibly indicating free riding on the diversification ecological benefits by others. We also examined heterogeneity in preferences based on producer characteristics. Producers reliant on syrup income, those with lower discount rates (greater patience and long-term orientation), and risk-tolerant individuals are more likely to adopt diversification. In contrast, those managing larger sugarbushes are less inclined to pursue diversification. These insights provide evidence to inform the design of effective incentive structures and contract terms that can support broader adoption of forest diversification practices. Final data collection, including responses to an information treatment embedded in the CE, will be completed by April 2025 to validate and expand on these findings. Objective #4. Benefits and trade-offs of key ecosystem services. To quantify the benefits and tradeoffs of key ecosystem services generated from forests comprised of diverse sap-producing tree species at the landscape level, we have queried the publicly available Forest Inventory and Analysis data to obtain county-level data for each of the 7 study species including numbers of trees, basal areas, sawtimber volumes, aboveground carbon estimates, aboveground biomass estimates, diversity indices, numbers of seedlings, forested acreages, and basal area percentages for each study species. These data will be used to estimate tradeoffs between carbon stocks, sawtimber volumes, and syrup production across the region (for all areas where our study species - both syrup-producing and potential syrup-producing species - are found). This work will continue into 2025, in collaboration with Chris Woodall and Katie Renwick from the United States Forest Service A central tradeoff identified in this study is between short-term yield losses and long-term ecological resilience benefits. While diversification can enhance forest resilience to climate extremes and provide long-term stability, producers expressed aversions to immediate reductions in maple syrup yield. This suggests that private incentives are misaligned with the temporal distribution of diversification benefits, which tend to materialize gradually and with uncertainty. The intertemporal nature of this tradeoff is particularly salient in perennial systems, where sunk costs and delayed payoffs are prominent. As such, the results emphasize the importance of incorporating dynamic payment structures within PES program design to mitigate the initial economic disincentives and support broader adoption of resilience-enhancing practices.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
Yan, Y., Atallah, S. S., M. J. Khan, and D. Moore (2024). Maple Syrup Producers' Willingness to Diversify Maple Forests for Increased Resilience. Presented at the Agricultural and Applied Economics Association (AAEA) 2024 Annual Meeting, July 28-30, New Orleans, LA. DOI: 10.22004/ag.econ.343860. https://ageconsearch.umn.edu/record/343860
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
Moore, D.B., H. M. Vadeboncoeur, H. Asbjornsen. 2024. Tap Design. Maple Syrup Producers Association of Connecticut. November 9, 2024.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
Yan, Y., Atallah, S. S., M. J. Khan, and D. Moore (2024). Maple Syrup Producers' Willingness to Diversify Maple Forests for Increased Resilience. Economic Valuation and Management of Natural Resources on Public and Private Lands Conference, Fort Collins, CO, February 28 - March 1, 2024.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
Yan, Y., Atallah, S. S., M. J. Khan, and D. Moore (2024). Maple Syrup Producers' Willingness to Diversify Maple Forests for Increased Resilience. Agricultural and Applied Economics Association, New Orleans, LA, July 2024.
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Progress 01/01/23 to 12/31/23
Outputs
Target Audience:We targeted syrup producers, scientists (including other tree physiologists and syrup researchers), natural resource managers, interested landowners, and the general public (especially syrup consumers) with our research and outreach activities, as described in detail below. Changes/Problems: During this past reporting cycle, we experienced four problems that required minor changes to our planned activities. The pressure sensors (Omega Engineering, Norwalk, CT) that were used to monitor vacuum levels were recommended to us by other well-established syrup researchers. However, our experience with these sensors has been mixed, possibly due to these sensors not being specifically calibrated for negative (below-atmospheric) pressures. This is important, because a large percentage of the pressures in deciduous, woody angiosperms during winter dormancy are below atmospheric pressure. Thus, further lab validation is needed to determine how accurate they are at measuring low pressures so we can be confident in the claims we will make about how tap barrel lengths affect vacuum levels. To address this issue, we plan to conduct a rigorous lab validation and calibration of these pressure sensors once the 2024 field season ends using known vacuum levels. Second, our axial (vertical) measurement positions for the wood temperature and stem pressure sensors were located at ground level, at breast height, and in the canopy. For some species of trees, the distance between the breast height measurements and the canopy measurements was about 1 m, but for others, this distance was as large as 20 m. Thus, there is quite a bit of uncertainty in our calculated values of wood temperature and stem pressure axial gradients when these distances were large due to these gaps in the measurements. Future studies should include more regular axial measurement intervals with more numerous sensors located across shorter distances. Third, we were not able to obtain any xylem sap osmolality measurements in 2023. The 'jet-discharge' method of extracting xylem sap from wood cores using a pressure bomb, described in several peer-reviewed journal articles, did not work on our wood cores, and attempts to communicate with the authors of these journal articles were not successful. Twig samples also did not yield as much sap as we had expected. To address this issue, we have developed and tested a more effective approach for extracting xylem sap that we are using during the 2024 field season.This approach involves drilling small holes at the ground, breast-height, and canopy positions along the tree stem and using a syringe to extract sap from each hole. Putty is used to seal where the syringe needle enters the hole, and a manual pneumatic vacuum pump (used in the automotive industry for bleeding brake lines) is connected to the syringe and used to generate enough negative pressure for sap to be extracted under most conditions. This technique is currently being used during the 2024 field season with a high degree of sucess. Fourth, in assessing maple syrup producers' willingness to adopt the production of novel tree syrup, we face the usual problem of low response rates by producers. Currently, we are contracting with a survey firm to supply us with the mailing address of maple syrup producers. However, the sample size is too small. To address this, we plan to augment our sampling approach by incorporating email addresses of maple syrup producers. This expansion will help increase the sample size at the risk of increasing selection bias. What opportunities for training and professional development has the project provided?Ph.D. candidate David Moore enhanced his professional development by participating in an international maple syrup producer conference an academic conference (a sap flow workshop). At the maple syrup producer conference, interacted with several preeminent maple syrup researchers (e.g., Adam Wild, Cornell University; Matthew Watson, University of Canterbury, NZ), building his professional network, sharing ideas and learning from others, and exploring opportunities for future collaboration. This past year, Moore also improved his R coding skills, his CRBasic coding skills, his ability to craft an effective public oral presentation, and his understanding of canopy access techniques. Furthermore, while working on a manuscript for publication, David learned about freezing-point-depression measurement techniques and will apply these techniques to his sap samples this year to understand more completely how freeze-thaw dynamics affect sap flow, stem pressure, and wood water content, thereby strengthening the interpretation of his results for future publication. Additionally, four undergraduate students and one high-school volunteer learned how to assemble sap flow and stem pressure sensors for field monitoring of sap flow dynamics, including soldering techniques and basic electrical engineering principles. One graduate student and a high-school volunteer got experience and instruction on safe chainsaw operation. Graduate student Tanner Frost gained valuable experience climbing trees to help with the installation and removal of canopy wood temperature and stem pressure sensors. Ph.D. student Yizun Yan enhanced her skills in choice experiment design, econometric estimation, software proficiency, and survey framing throughout the project. Yizun crafted the choice experiment survey utilizing a D-optimal design approach and conducted a pretest of this survey at the 2023 North American Maple Conference. Using pretest data, she skillfully applied conditional logit model and mixed logit model to obtain initial estimates, which were then used as Bayesian priors to generate the final choice design. From this process, she learned how to use and to cross-validate among different software tools, including R, Stata, JMP and Ngene in discrete choice model and data analysis. Furthermore, Yizun learned how to frame survey questions in a way that elicits meaningful insights from producers' perceptions and preferences in decision-making. How have the results been disseminated to communities of interest?The primary target audience for the agroforestry-related research is landowners, farmers, producers, and other stakeholders interested in implementing diverse agroforestry systems on their lands, as well as natural resource managers and policy makers who need science-based information on which to base their decisions, and consumers who are interested in learning more about different agroforestry products and where they can be obtained. We disseminated results to scientists at the 12th International Workshop on Sap Flow, to syrup producers at a professional conference (the 2023 International Maple Syrup Conference), five media appearances, five taste-testing events, and informally, through interactions with our team's extensive network syrup producers in the region. The taste tests and the media appearances were especially important, as many consumers had never realized that syrup production from trees other than maples was possible. When taste test participants were asked about their syrup preferences, approximately 50% stated a non-maple syrup as their favorite, with beech, sycamore, and birch syrups being the three top choices after maple. Increasing consumer awareness of and preferences for alternative syrups is an important first step towards creating new markets for diverse tree syrup products. Finally, as part of an international exchange visit whereby UNH hosted a group of forestry researchers and professionals from Bangladesh, PhD student Moore gave a presentation and facilitated discussion about his syrup diversification research. In Bangladesh, date palm syrup is an important product, and the similarities between maple syrup production and date palm syrup production may open opportunities for future collaboration. Both syrup producers and consumers have benefited directly from PhD student Moore's research on diversification of the syrup industry--producers have obtained information regarding techniques for producing syrup from sap extracted from trees other than maples, while consumers have had opportunities to taste diverse syrups and received information on where they can purchase these syrups throughout the region. The interest among these stakeholders in this research is reflected by them actively reaching out to PhD student Moore for information, with the result that Moore communicated with approximately 25 maple syrup producers and interested landowners on how to produce syrup from different types of trees, and about 40 interested consumers on where to obtain syrups from different tree species. As both producers and consumers become more knowledgeable about the potential for diverse tree species to produce interesting and flavorful syrups and to contribute to forest conservation and climate resilience, this should lead to growing market opportunities for producers to diversify their income base, as well as an increase in incentives for landowners and other forest managers to conserve and sustainably manage different types of forests and for consumers to directly support local industries and climate adaptation. What do you plan to do during the next reporting period to accomplish the goals?Goal #1. During 2024, we plant to collect data on xylem sap osmolality, while continuing to collect measurements of bark respiration, sap flow, wood temperature, stem pressure, and wood water content measurements. Combined, these data will allow for a more complete analysis of the drivers of sap flow dynamics across our study species. We will also perform chemical analyses, including both gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS), on all the sap and syrup samples collected during the first two years of the project. These analyses will allow us to identify the different compounds and their amounts present in all our sap and syrup samples. During the coming field season, we will fell 35 of the study trees that were tapped in 2022 and 2023 and cut cross-sections ('cookies') that include the area of each stem affected by tapping. Each cookie will be planed, sanded, photographed, and analyzed with image-analyzing software to estimate the size of the nonconductive wood columns above and below old tap holes. Additionally, the cookies will be used to quantify annual radial growth rates to determine whether radial growth rates are compensating for the loss of hydraulically conductive wood each year due to tap hole wounds. Combined, these results will be used to generate tapping guidelines for these novel species. Goal #2: We will implement our final Bayesian choice design with a representative sample of maple syrup producers. We are now contracting a survey firm to supply us with the mailing addresses of maple syrup producers. In the final survey, we include two information treatments where we randomly provide respondents information about projected declines in syrup yields across most of the U.S. range under future climate scenarios and about the premium consumers are willing to pay for syrup produced from diversified forests. The survey includes perception questions that will help us better understand producer preferences and the extent to which they are driven by the market or by environmental considerations. Analysis of these incentives and barriers to adoption is needed to predict where and how many producers might adopt production of novel tree syrup, providing vital insights for the industry and policymakers interested in increased diversification for the purpose of increased resilience in agriculture and forestry. Willingness-to-adopt estimates are useful to policymakers and stakeholders to develop targeted interventions and support mechanisms, promoting sustainable practices and enhancing the industry's resilience against environmental challenges.
Impacts
What was accomplished under these goals?
This project addresses the need to understand the potential for diversifying the maple syrup industry to include other non-maple tree species as a strategy for adapting to future climate change by increasing the biodiversity of sugarbushes while also developing new opportunities for market expansion and income diversification for producers and landowners. Diversification of the maple syrup industry also has the potential to enhance climate mitigation by promoting conservation of forest ecosystems and increases in total carbon sequestration and storage. In the absence of diversification, the long-terms sustainability of the maple syrup industry, which comprises and important cultural, economic, and ecological land use practice in New England, is threatened by climate change-induced rising temperatures and increasing drought frequency, given the high sensitivity of sugar maple to environmental change. Goal #1: Patterns and drivers of dormant season sap flow. To determine the drivers of winter-dormant-season sap flow, and sap pressurization, we collected continuous (15-min) data during the winter and spring of 2023 when study species were dormant. In three trees of each of the study species (i.e., sugar maple, paper birch, American beech, American sycamore, hophornbeam, basswoods, speckled alder), we monitored wood water content, sap flow, and wood temperature and stem pressure at ground level, breast height, and in the canopy. We calculated axial (vertical) and radial gradients of wood temperature and axial gradients of stem pressure, and analyzed the degree of correlation between these variables. Sap was harvested from these species to produce syrup used in taste-testing events to understand consumer preferences. Sap and syrup samples will be analyzed for chemical composition. This past year, we also focused our efforts on analyzing and interpreting data collected over the past 5 years and developing and writing manuscripts. Preliminary results thus far suggest that, contrary to our hypothesis, freeze-thaw events appear to drive sap flow events during winter dormancy in nearly all study species, despite differences in the timing of their maximum sap yield. This suggests that stem pressure may be a stronger driver of sap yield than sap flow--a hypothesis that will be tested this coming year. Goal #3. Assess consumer preferences and willingness to pay. To assess maple syrup producers' willingness to adopt production of novel tree syrups, we designed a choice experiment (CE) that elicits maple syrup producers' preferences and their willingness to adopt maple forest diversification. Our CE asked maple syrup producers to make choices over different diversification programs, characterized by seven attributes (e.g., diversification intensity, annual syrup yield reduction from competition, increased resilience, neighbor's adoption rates, equipment needs, contract length, and payment). Our preliminary findings from the pilot study indicate that diversity intensity, yield reduction, and contract length significantly influence producers' preferences. We identify a nonlinear preference for diversification intensity, with a favored range of 25% to 50% non-maple species. This aligns with ecological studies indicating a non-linear link between biodiversity and ecosystem functionality, due to diminishing marginal benefits of diversity in ecological systems shaped by complex interspecies interactions. Our findings on contract length diverge from the existing literature on annual systems, as we found that producers prefer a 15-year contract but are less likely to enroll in a 10-year contract, suggesting that for perennial systems, forest diversification is characterized by longer-term planning and slower maturation of environmental benefits. To assess maple syrup producers' willingness to adopt production of novel tree syrups, we designed a choice experiment for maple syrup producers that elicits maple syrup producers' preferences and their willingness to adopt maple forest diversification. We conducted a pretest with 144 participants at the 2023 North American Maple Conference: Quality from Tree to Table. Our preliminary findings from the pilot study indicate that diversity intensity, yield reduction, and contract length significantly influence producers' preferences. Combined, these accomplishments during the 2023 reporting cycling have advanced our understanding of the drivers of sap flow and the potential for syrup production from seven non-maple tree species, as well as the potential for developing economically viable markets for diverse tree syrups based on consumer preferences and willingness to pay. This information will help inform decision making and management approaches by producers interested in expanding their syrup production systems to enhance their future sustainability, climate resilience, and profitability.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Moore, D.B., M.A. Vadeboncoeur, J. Gutierrez Lopez, T. Frost, and H. Asbjornsen. 2023. Modeling Winter-Dormant-Season Sap Flow in Deciduous, Woody Angiosperms in New England. 12th International Workshop on Sap Flow. Nov. 3, 2023. Rotorua, New Zealand.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Moore, D.B., M.A. Vadeboncoeur, J. Gutierrez Lopez, T. Frost, J. Ehmett, and H. Asbjornsen. 2023. Sap Flow, Stem Pressure, and Sap Yield: Using Tree Physiology Data to Draw Conclusions About Syrup Production. 2023 International Maple Syrup Conference. Oct. 27, 2023. Sturbridge, MA.
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Progress 01/01/22 to 12/31/22
Outputs
Target Audience:The target audience for this project includes diverse stakeholdersthroughout the northeast region who are interested in the syrup industry, including syrup producers, woodland owners, and farmers, as well as consumers and the general public. Given the important cultural, ecological, economic, and historical importance of thesyrup industry in New England, this project has the potential to attract braod interest in the region. Changes/Problems:The biggest challenge faced with Goal #2 in 2022 was that the datalogger script not working properly - we were not able to collect and data on sap flow, wood temperature, wood water content, or stem pressure. This problem was fixed and data is currently being collected (we had a second field season as part of the project), so we will ultimately end up with plenty of data to analyze. These data are being collected to determine what drives sap flow and sap pressurization (and thus sap yield) during winter dormancy. For Goal #3, due to Covid-19, the study was modify to a lab-based experiment. It was very challenging to meet the Covid-19 guidelines, requiring volunteers to help with the process. To make sure we were controlling for Covid-19 related taste impairments,we also included a separate question in our survey regarding the taste buds. Giventhese challenges, we are currently considering the possibility of conducting a follow up field-based consumer survey during the third project year that would include more diverse consumers and tree syrups, as well as new information about the health and ecosystem service benefits of diversified sugarbushes, which we anticipate becoming available after the upcoming second project year. What opportunities for training and professional development has the project provided?This project partially supported Mr. Muhammad Jawad Khan to complete his PhD dissertation at UNH focused on understanding consumer willingness to pay for diversified tree syrups.The research results were shared among the public through, seminars, and conference publications. This project is currently providing partial support for Mr. David Moore to conduct his PhD dissertation research on the plant biological, physiological, and phytochemical aspects of syrup production from diverse tree species. Three undergraduate research assistantslearned how to construct sap-flow sensors and the theory behind how sap-flow sensors work. Graduate student Tanner Frost received training in tree climbing, which allowed him to provide invaluable assistance with intalling the sap flow sensors in the tree canopies forthisproject. Mr. Frost has also providing training to two other graduate students in our lab in tree climbing techniques and safety measures. Graduate studentDavid Moore learned how to operate the two NMR spectrometers owned by the University of New Hampshire's Instrumentation Center, and he also audited a spectroscopy course (CHEM 808 - Spectroscopic Investigations of Organic Molecules) at UNH during the fall 2022 semester as well. This skills enabled him to conduct the phytochemical analysis of his tree syrups. How have the results been disseminated to communities of interest?Four of the syrups produced as part of this project (maple, birch, beech, and sycamore) were featured in the University of New Hampshire's 'Taste of COLSA' event on Oct. 7th, 2022, which served as an outreach opportunity to teach students, faculty, and the public about the potential for producing syrup from non-maple tree species. Graduate student David Moore gave a tour of an AFRI study site to a high-school FFA group (led by their teacher, Audra Leach) from Housatonic Valley Regional High School on Mar. 27th, 2022. Graduate student David Moorespoke with about half a dozen syrup producers informally about producing syrup from different tree species other than sugar maple. Graduate student Moore presented his research resultson how to harvest sap and produce syrup from trees other than maples at the New England Society of American Foresters annual meeting in Portland, ME on Mar. 24th, 2022. He also gave a presentation onhis sap-flow modeling techniques at a departmental seminar on Apr. 26th, 2022. The results from our study on consumer willingness to pay for tree syrupsderived from diversified forests were presented atthree different conferences (see details above). These conferences included people from academia, industry, students, and other researchers. What do you plan to do during the next reporting period to accomplish the goals?Goal #1: We are currently collecting (and will later analyze) sap flow, stem pressure, wood temperature, and wood water content data (as well as environmental data) to determine the factors that drivesap flow and sap pressurization during winter dormancy. Wood temperature and stem pressure are being monitored at three heights in each study tree (in the root flare, at breast height, and in the canopy), and sap flow and wood water content are being monitored at breast height only. Goal #2: We plan to analyze all of the sap and syrup samples produced from this study thus far using both gas chromatography and liquid chromatography for their phytochemical properties. We will corroborate these data with the data we have already produced from NMR spectroscopy during the first project year. Goal #3: We will draft a choice experiment (CE) survey to be deployed with syrup producers. We will conduct two focus groups of syrup producers, one in New Hampshire and one in Illinois, to identify the major determinants of producer's potential decision to adopt novel syrups. We will use a shortlist of these adoption determinants to define the attributes and the attribute levels to be used in a survey-based choice experiment (CE). In addition to identifying the attributes, we will ask the focus group participants to help review a draft survey questionnaire aimed at understanding producers' preferences regarding syrup diversification. The survey will elicit information in four areas: (1)forestcharacteristics, (2) choice experiment, (3) attitudes, beliefs, and cultural values, and (4) individual socio-economic information. The CE will consist of asking respondents to choose among hypothetical choice options described in terms of their attributes and a given cost of adoption. The attributes, to be confirmed in the focus groups, are likely to include the specific technology adoption method (e.g., species, syrup yield, syrup extraction technology; Obj. #1), changes in ecosystem service outcomes as a result of adoption (e.g., increases in biodiversity, carbon storage, sawtimber; Obj. #4), whether neighbors are adopters, and a given adoption cost or subsidy (Obj. #1).
Impacts
What was accomplished under these goals?
Objective #1: Due to technical problems, work related to this Objective was deferred to the second project year (see details provided below). Objective #2: We performed nuclear magnetic resonance (NMR) spectroscopy on sap and syrup samples from sugar maple (Acer saccharum), paper birch (Betula papyrifera), American beech (Fagus grandifolia), American sycamore (Platanus occidentalis), alder (Alnus spp.), American basswood (Tilia americana), and American hophornbeam (Ostrya virginiana). Although the sugar in sap and syrup from sugar maple is primarily sucrose, the sugar in all the other 6 species is primarily fructose and glucose. Refractive index and pH data were measured for all sap and syrup samples as well. Preliminary results are currently being analyzed and compiled into a manuscript and outreach materials. Objective #3: We completed initial data collection and analysis of consumer willingness to pay for different tree syrups relative to syrups produced from sugar maple. This analysis included an assessment of information on the benefits of diversified forests affects willingness to pay. The results indicate that consumer preferences might support the future diversification of maple forests, especially if labeling can successfully deliver the information on the ecological benefits of forest diversification. Objective #4: Work on this project component has not been started yet, as we first need the results from Objectives #1-3.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Moore, D., T. Frost, M. Vadeboncoeur, and H. Asbjornsen. 2022. Harvesting Sap and Producing Syrup From Trees Other Than Maples. New England Society of American Foresters annual meeting. Portland, ME.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Moore, D., and J. Gutierrez Lopez. 2022. Using an n = 1 Hermite Function to Model the Relationship Between Sugar Maple Winter-Dormant-Season Sap Flow and Wood Temperature. University of New Hampshire Department of Natural Resources and the Environment Seminar Series. Durham, NH.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Khan, M.J., S. Atallah, M.H. Kalaitzandonakes, B. Ellison. 2022. Consumer willingness to pay for tree syrups derived from diversified forests. Agricultural & Applied Economic Association (AAEA) Annual Meeting, Anaheim, CA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Khan, M.J., S. Atallah, M.H. Kalaitzandonakes, B. Ellison. 2022. Consumer willingness to pay for products derived from diversified forests: the case of tree syrups. Northeast Agricultural and Resource Economics Association (NAREA), Mystic, CT.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Khan, M.J., S. Atallah, M.H. Kalaitzandonakes, B. Ellison. 2022. Consumer willingness to pay for products derived from diversified forests: the case of tree syrups. Heartland Workshop, Urbana IL.
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