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Article

Sugar Maple and Red Maple Face-Off: Which Produces More and Sweeter Sap?

by
Aya Garfa
,
Roberto Silvestro
,
Sara Yumi Sassamoto Kurokawa
,
Sergio Rossi
,
Annie Deslauriers
and
Serge Lavoie
*
Département des Sciences Fondamentales, Université du Québec à Chicoutimi, 555 Boulevard de L’Université, Chicoutimi, QC G7H 2B1, Canada
*
Author to whom correspondence should be addressed.
Appl. Sci. 2025, 15(3), 1091; https://doi.org/10.3390/app15031091
Submission received: 27 November 2024 / Revised: 17 January 2025 / Accepted: 21 January 2025 / Published: 22 January 2025
(This article belongs to the Section Ecology Science and Engineering)
Browse Figures
Versions Notes

Abstract

:
Among the species used for syrup production, sugar maple (Acer saccharum Marsh.) is preferred by producers, while red maple (Acer rubrum L.) is considered less productive in terms of sap yield and sugar content. This study aims to measure the volume and physicochemical characteristics of the sap produced from two red maples and two sugar maples during the 2023 sugar season in a commercial sugarbush in Laterrière (QC, Canada). Sap exudation was measured continuously with the gravity method using automatic rain gauges. Sap production was discontinuous and heterogeneous, reaching 2.6 L during the most productive day. No significant difference was found in the daily production between species, but we observed a difference in the cumulative sap production (7 L in red maple vs. 13.5 L in sugar maple) due to a longer period of sap exudation in the latter. Despite daily variations in pH, Brix values, sucrose concentration, osmolality, and conductivity, no differences in physicochemical characteristics were detected between species.

1. Introduction

In Canada, and particularly in Quebec, maple hold an emblematic place and play a major economic and cultural role. The country has built a special industry around this species, namely, the production of maple syrup and its derived products, supporting local economies through job creation and sustainable agricultural practices, fostering economic stability and growth in maple-producing regions [1,2]. Quebec is the world’s largest maple producer, accounting for 89.9% of the syrup production in Canada [3]. Maple syrup is an international industry, with production and consumption extending far beyond its North American origin [4]. Nowadays, maple syrup is consumed in more than 50 countries worldwide [5]. Over time, the maple industry in North America has shown robust growth, with >60 M trees tapped in 2022 [6]. This expansion is driven by the rising market, but is challenged by the uncertainties of a changing climate. Fluctuating weather patterns and altered seasons impact sap flow and production schedules, necessitating adaptive strategies to sustain yields and quality to face environmental changes.
There are about 150 species of maples on Earth, but only a dozen are native to North America [7]. Among these, the most commonly tapped species for syrup production are sugar maple (Acer saccharum Marsh.), its close genetic relative black maple (Acer nigrum F. Michx.), red maple (Acer rubrum L.), and, to a lesser extent, silver maple (Acer saccharinum L.) [6,8]. The primary factor driving the wide use of these species in the maple industry is the high sugar content of their sap, which is an essential trait for a sustainable production of high-quality syrup [9,10,11]. Among species, the sugar maple is favored by producers as an iconic species for the industry [12,13,14]. This preference is mainly due to some expected differences in sap yield and sugar content between species, particularly between sugar maple and red maple [6]. However, these differences between species could be due to the effects of microsite conditions and still remain to be quantified and confirmed experimentally. Yet, a deeper understanding of these differences is essential for providing clear guidance to producers on managing their sugarbushes effectively, as well as for developing strategies to adapt the industry to the future climate scenarios.
The distinctions between sugar maple and red maple extend beyond sap yield and chemical composition. These differences also include significant ecological variations that are crucial for their current and future roles in the maple syrup industry. Both species are primarily found in the northeastern United States and southeastern Canada, the core of maple syrup production. Particularly at higher latitudes, these species frequently coexist within the same stands. However, their pronounced ecological differences have important implications for their management. Sugar maple can form stands pure or mixed with other hardwoods and conifers [15]. This species grows in rich and fertile soils and is affected by adverse conditions such as pollution and soil compaction [16,17]. Red maple is widespread throughout the deciduous forests of eastern North America, extending into the boreal forest borders [18,19]. Unlike sugar maple, red maple rarely forms pure stands, and adapts to a wide range of environmental conditions. Indeed, red maple is commonly considered more versatile than sugar maple, as it can thrive on a broader spectrum of soil types, textures, moisture, and pH [17,20,21]. While optimal growth conditions occur in moist, fertile, loamy soils, it also manages well in dry, rocky, upland sites [20,21]. This high versatility of red maple could potentially enhance its competitive success compared to sugar maple and contribute to its expansion in response to climate change.
Sugar maple is the most abundant species of the maple syrup industry, but other maple species, notably red maple, represent potential alternative syrup sources. A recent study compared these two species regarding sap yield, sugar content, and physicochemical properties [6]. According to this study, sugar maples generally yield more and sweeter sap than red maples, with a mean difference of 0.51 ± 0.58° Brix in sugar [6]. This difference highlights the potential advantages of sugar maple for syrup production but still suggests that red maple could contribute to the maple industry expansion, particularly in regions where sugar maple is less adapted [22]. A better understanding of the difference between the saps produced by sugar maple and red maple would allow the maple syrup industry to develop new strategies to address the challenges posed by climate change, including harvest optimization, maintaining production profitability, and preserving a high quality of maple syrup.
Three characteristics are typically assumed to give sugar maple an advantage over red maple in syrup production: (i) sugar maple exhibits a longer sap production season, primarily due to a later cessation of sap exudation compared to red maple; (ii) this extended season should result in a higher sap yield; and (iii) sugar maple should have a higher sugar content compared to red maple [10]. This study aims to test the abovementioned differences between the two species using high-resolution temporal measurements of sap production collected on sugar maple and red maple growing under the same environmental conditions. We challenge the hypotheses that there are significant differences in sap season, sap yield, and sugar content between the two species.

2. Materials and Methods

2.1. Study Site and Tree Selection

The study site is located within a commercial sugarbush in Laterrière (48°28′ N, 71°14′ W, 230 m a.s.l.), QC, Canada (Figure S1) [23]. The stand is characterized by a mixed forest belonging to the balsam fir (Abies balsamea (L.) Mill.) yellow birch (Betula alleghaniensis Britton.) domain. The climate of the area is typically boreal with cold and long winters and warm but short summers. The average annual temperature is 3.5 °C, with extreme temperatures reaching −42 °C in January and 36.3 °C in June. The annual precipitation is 1160 mm. Temperatures lower than 0 °C are observed for 137 days, spanning from October to May. The soil consists of podzol, with a MOR-type humus and an organic horizon of 10–20 cm in depth.
A group of four trees including two red maples (Acer rubrum L.) and two sugar maples (Acer saccharum Marsh.) were tapped during the period from March to April 2023. The trees, exhibiting a similar diameter at breast height of approximately 20 cm, well represented the maples of the sugarbush. All selected trees were mature, healthy, untapped, and dominant.

2.2. Monitoring Sap Season and Production

For sap collection, we followed the standard tapping protocol used by maple syrup producers. Before the onset of the sugar season, a notch was drilled into the stems with a diameter of 8 mm and a depth of 5 cm at a height of approximately 2 m and an angle of about 10° downward to ensure the sap flows into the collector. The drill bit was previously disinfected with a 70% isopropanol solution to minimize bacterial proliferation. A plastic spout was inserted into the notches, connecting to the tipping bucket rain gauges (HOBO Data Logging Rain Gauge RG3-M, Bourne, MA, USA) with a plastic tube. The rain gauges, as automated sap collectors, were installed on the study trees and operated continuously, recording sap volume at hourly intervals for the entire sap season. The upper openings of the rain gauges were securely sealed to prevent rain, snow, and debris from the canopy from falling into the system and affecting the measurements. A volume of 3.73 mL of water is recorded each time the tip fills, and the switch is subsequently activated, allowing a precise and automatic assessment of sap flow rates, timing, and duration. The volumes recorded were corrected using a conversion rate of 1.32 g/mL to consider the higher density of the sap compared to water [24]. The daily sap volume was calculated as the sum of the hourly yield. All equipment was calibrated and disinfected before the sugar season to maintain measurement accuracy.

2.3. Physicochemical Analysis of Sap

Eight milliliters of sap were collected from each tree at a daily resolution, excluding the days with absent sap exudation. The sap was collected between 1 pm and 3 pm from the tubes connected to the spouts. Part of the sample was analyzed directly in the field, and the remaining part was preserved in vials at −80 °C for laboratory analyses. Before each measurement, the sap was homogenized using manual agitation for a few seconds to ensure a uniform distribution of its components. In the field, we conducted physicochemical measurements to characterize maple sap based on pH, conductivity, and soluble solid organic matter concentration.
The pH was measured using a SevenGo Duo Pro pH meter (Mettler Toledo SG78, Greifensee, Switzerland) with temperature compensation, equipped with an InLab® Expert Go-ISM electrode (Mettler Toledo No. 51344102, Greifensee, Switzerland), suitable for pH measurements ranging from 0 to 14. Conductivity was expressed in microsiemens per centimeter (µS/cm) and obtained using an InLab® 738-ISM electrode (Mettler Toledo No. 51344110, Greifensee, Switzerland), with a conductivity range of 0.01 to 1000 mS/cm. Before measurements, the pH meter was calibrated using buffer solutions for pH values of 2, 4, 7, 9, and 10 and conductivity standards of 84 µS/cm, 1413 µS/cm, and 12.88 mS/cm. Soluble solid concentration (°Brix) was assessed using a PAL-Maple digital hand refractometer (Atago Co., Ltd. AT3849-000, Tokyo, Japan) equipped with a temperature compensation system. Before each measurement, the refractometer was calibrated with distilled water The Brix was measured using 0.3 mL of sap. The conductivity measurements were performed in triplicate for each sample. For pH and soluble solid concentration, measurements were performed only once, but the repeatability of the instruments was evaluated by measuring the same sample 10 times. In both case, the variance was less than 0.1%.

2.4. Osmolality of Sap

The osmolality was measured from freezing point depression determination using an OsmoTECH PRO Multi-Sample Micro-Osmometer (Advanced Instruments, Norwood, MA, USA). Before each measurement, the instrument was calibrated with a two-point calibration method, using pure water and a KCl solution at 0.1 M (mol/L). Results were obtained from three samples of each solution, with each sample measured in triplicate for accuracy. A 5 µL volume was used for the osmolality analysis. The concentration values of osmolality are expressed in mOsm/kg H2O.

2.5. Sugar Profile of Sap

The sugars were quantified using a Gallery™ Plus Discrete Analyzer (Thermo Fisher Scientific™, Oy Rastasties 2, Fi-01620, Vantaa, Finland), a photometric analyzer. For this purpose, an initial assay kit for raffinose, sucrose, and glucose (Megazyme, K-Rafgl, Bray, Ireland) was used to determine total sugars. Depending on the enzymes used during the analysis, this kit allows the quantification of trisaccharides separately from disaccharides. Several attempts conducted using the complete enzyme set from the kit demonstrated that raffinose, stachyose, and verbascose were absent from the sap.
A second assay kit for glucose and fructose (Megazyme, K-Sufrg, Bray, Ireland) was employed to measure their individual concentrations. A volume of 12.5 µL of sap was injected into the analyzer to obtain the concentration of each sugar. All results were expressed in g/L. The detection limit was 0.2 g/L for total sugars (mostly sucrose) and 0.1 g/L for glucose and fructose. In order to ensure the reliability of the results, we first assessed the instrument’s repeatability by performing 10 measurements on the same sample. Given a relative standard deviation of less than 0.1%, the other sample was measured only once.

2.6. Statistical Analysis

Statistical analysis was performed with mixed-effects models using JMP PRO 17 software (SAS Institute Inc., Cary, NC, USA). We compared all measured variables between the two maple species after checking the assumptions of homogeneity of variances using the O’Brien test and normality using Shapiro–Wilk tests. Models were applied on log-transformed data when the assumption of normality was not reached. The model included the species as a fixed effect and the individual tree as a random effect.

3. Results

3.1. Sap Season and Yield

Red maples and sugar maples showed different duration of the sap season, with red maple completing sap exudation 7 days earlier than sugar maple (Figure 1). The sap season began on DOY 86 and 88 in red maple and sugar maple, respectively. Sap production continued until DOY 112 in red maple and DOY 119 in sugar maple.
Daily sap production represents the average volume produced per tree. Both species exhibited similar yields and fluctuations in sap volume during the sap season (p > 0.05; Figure 1). The daily production in sugar maple ranged from 0 to 2.6 L, while in red maple, production varied from 0 to 2.1 L. Sap flow reached a maximum in both species between DOY 100 and 112, the middle of the sap season. In both species, this peak in yield was followed by a gradual decrease toward the ending of the sap season (Figure 1).
We analyzed the cumulative sap production over the sap season. At the beginning, sap volume was low in both species (Figure 2). Red maple started with 0.6 L on DOY 86, while sugar maple produced 0.2 L on DOY 88. From DOY 86 to 102, red maple was more productive than sugar maple. As the season progressed, both species increased sap yield, presenting the highest cumulative sap on DOY 112 and 117 in red maple and sugar maple, respectively. Sap volume in red maple achieved 7 L at the end of the season, while sugar maple produced 13.5 L (Figure 2).

3.2. Brix Measurements

The concentration of dissolved organic solids, expressed in degrees Brix (°Brix), showed similar temporal variations throughout the sap season between the two species (Figure 1). Daily assessments confirmed the absence of significant differences between red maple and sugar maple, with p > 0.05. The concentration of dissolved organic solids during the sap season varied between 2.4 and 3.9 °Brix and between 2.6 and 4.0 °Brix in red maple and sugar maple, respectively. At the beginning of the sap season, sugar maples exhibited an average degree Brix of 4.0 on DOY 88, gradually declining to 2.8 on DOY 119. Red maples started with an average degree Brix level of 3.0 on DOY 86, diminishing slightly to 2.6 on DOY 112. Peaks in Brix concentration were mainly observed at the beginning and in the middle of the sap season, with sugar maple and red maple reaching 4.0 and 3.9 °Brix on DOY 88, respectively.

3.3. Sugar Content

Sucrose was the main soluble sugar in the sap of both species during the entire sugar season, ranging from 20.2 to 41.7 g/L in red maple and from 21.5 to 45.2 g/L in sugar maple (Figure 1). Overall, the sucrose concentration showed no significant difference between species (p > 0.05). The sucrose concentration was high at the beginning of the sap season and decreased toward the end of the season. The concentration of sucrose in red maple was 35.2 g/L on DOY 86, reaching 20.2 g/L at the ending of the season on DOY 112. Sugar maple exhibited an initial sucrose concentration of 45.2 g/L on DOY 88, reaching 32.1 g/L on DOY 119.
During the entire sap season, the concentrations of glucose and fructose remained below the detection limit in both species. Increases in glucose and fructose concentrations were detected just in red maple when we tried to extract the sap at the end of the season using a syringe, an artificial suction method to force sap collection. The sap extracted with the syringe was not accounted for in our analyses.

3.4. Osmolality

Osmolality revealed similar temporal patterns in the two species (Figure 3). Osmolality ranged from 71 to 130 mOsm/kg H2O in red maple and from 72 to 133 mOsm/kg H2O in sugar maple. Red maple started the season on DOY 86 with an osmolality of 96.6 mOsm/kg H2O and ended the season on DOY 112 with an osmolality of 82.9 mOsm/kg H2O. Sugar maple started the season with an osmolality of 133.3 mOsm/kg H2O on DOY 88 and ended the season with 87.3 mOsm/kg H2O on DOY 119 (Figure 3). Overall, no significant difference in osmolality was found between red maple and sugar maple (p > 0.05).

3.5. pH and Conductivity

The measured pH was not different between species (p > 0.05; Figure 3), ranging around neutral values. Overall, pH ranged from 6.5 to 7.6 in red maple. In sugar maple, pH varied between 6.2 and 7.8. The pH of red maple at the beginning of the season was 7.3, reaching 6.6 at the end the season on DOY 112. Sugar maple started the sap season with a pH of 7.6, reaching a pH of 6.8 at the end of the season (Figure 3).
The measurements of conductivity showed no significant difference between sugar maple and red maple (p > 0.05; Figure 3). Conductivity in red maple and sugar maple varied between 420.51 and 804.83 µS/cm and between 294.16 and 592.74 µS/cm, respectively. Red maple exhibited a conductivity of 527.49 µS/cm on DOY 86, reaching 521.49 µS/cm on DOY 112. Sugar maple showed a conductivity of 570 µS/cm on DOY 88, reaching 499 µS/cm on DOY 119. A high measurement of conductivity of 804.83 µS/cm was observed in one red maple tree on DOY 88, which corresponded to the beginning of the sap season. Sugar maples exhibited a more constant conductivity, particularly during the middle and ending of the sap season, from DOY 102 to 119.

4. Discussion

This study compared sugar maple and red maple, the two main species tapped for maple syrup production. Specifically, we assessed the timing of the sugar season, daily and seasonal yield, and physicochemical characteristics of the sap. According to our hypothesis, the results indicated a difference in the duration of the sugar season, leading to different seasonal sap yields. Contrary to our expectations, the two species showed similar concentrations in sugars and physicochemical characteristics of the sap.

4.1. Sugar Season and Sap Yield

Sugar maple and red maple showed a similar onset of the sap season, but our red maple ended sap exudation approximately 7 days earlier than sugar maple. Our results are in agreement with the literature, suggesting that red maple ends the sap season earlier than sugar maple [11]. Both species showed a seasonal trend in daily sap production, with an increase in the middle of the season, followed by a decrease toward the end of the season. These variations could be influenced by several seasonal factors, such as the pattern in temperature [25], day length [26], and snow melt [27,28,29], which drive the reactivation of tree growth in spring.
The difference in the duration of the sugar season contributed to the difference in sap yield between sugar maple and red maple. While the daily productions are not different, sugar maple has more productive days at the end of the sap season, resulting in greater overall seasonal production. Also, Rademacher suggested a higher sap yield in sugar maple compared to red maple [6]. However, an explanation for the difference in duration of the sugar season is still lacking, as, to our knowledge, no study has compared the phenology of these two species in detail. By studying bud break in forest and clearcuts, McGee showed that red maple reactivated 7 days earlier than sugar maple [30]. This observation was supported by observations in the field made by the producers, which supported the evidence that the timings of budbreak affect the duration of the sugar season. The bud break would explain the difference in the duration of the sugar season observed between the two species in our study. Our findings highlight the need for more detailed investigations on the spring phenology of these species. Comparative analyses should focus on the eco-physiological drivers behind the differences in budbreak timing and sap flow duration.

4.2. Sugar Content and Physicochemical Characteristics of Sap

Sugar maple and red maple showed a similar temporal pattern in soluble sugar content during the sap season. Our analyses indicated that the degree Brix varied similarly between the two species, closely mirroring the sucrose concentration. These results confirmed previous studies showing that sucrose represents 96 to 99% of the solid fraction of sugars in the sap of maple [14,31]. Another study showed that the sugar content (i.e., the degree Brix) of sap in sugar maple ranged between 2 and 2.5 [11]. Our results ranged between 2.6 and 4.0 °Brix. This difference may be attributed to the site, which is located at the northern limit of maple distribution, and characterized by colder temperature and more acid soils [32,33]. The Brix for sugar maple and red maple followed a similar pattern throughout the sugar season, indicating a similar sucrose concentration in the two species.
Both species demonstrated a relatively stable sucrose concentration, with a slight decrease toward the end of the sap season, which may be due to an increased bacterial activity associated with the rising temperatures in spring [28,31,34,35]. The trend in sugars is linked to the metabolism of the trees during growth reactivation [36]. A decrease in the sucrose concentration at the end of the season could be associated with microbiological activity within the sap throughout the growing season [37,38].
In our case, the concentrations of glucose and fructose were always below the detection limit, except for one sample of sugar maple obtained on the last day of harvesting, where the amount of glucose and fructose slightly exceeded the detection limit. Previous studies reported a higher sugar content in sugar maple compared to red maple [11,39]. However, we were unable to detect differences in sugar concentrations between the two species, which may be explained by site characteristics and the methods of data collection. Previous studies collected the sap using micropipette aspiration for two days in early April or from the pipe system [39]. Our method involved daily sap sampling throughout the whole season, providing a more comprehensive and quasi-continuous description of sap characteristics over the whole sugar season.
Our analyses revealed similar fluctuations in osmolality between the two species, which could be explained by the common physiological processes involved in sap exudation. This measurement indicates the concentration of dissolved compounds in the sap, such as sugar content (mainly sucrose), organic acids, and mineral ions. To our knowledge, this is the first time that osmolality has been described for maple. When comparing the osmolarity to the total concentration of dissolved solids, as determined using refractometry, or to the sucrose concentration determined using the enzymatic method, a very high correlation is observed. This is clearly explained by the dominance of sucrose in the sample, which accounts for between 96% and 99% of the dry matter in the sap [14]. The integration of osmolality in sap monitoring could lead to a better understanding of how maple trees manage their water balance and adapt to fluctuating environmental conditions [40,41].
Also, pH had similar seasonal pattern between the two species, characterized by neutral values at the beginning of the season, slightly decreasing to 6 toward the end of sap production. The pH available in the literature (ranging from 3.9 to 7.9) concerned sap from stands including both sugar maple and red maple [14,31], while specific information on the pH of maple species is lacking. By integrating the pH, we can obtain new information on the microbiological activity within sap throughout the season. Specifically, by monitoring the evolution of sap pH, we can track the microbial evolution of the sap, which will ultimately impact the maple syrup quality [34]. The slight decrease of the pH aligns with the increased concentration of organic acids, such as malic and succinic acid, as observed in other studies [31,42].
Potassium, sodium, calcium, and magnesium are the most abundant minerals present in maple sap [31]. Conductivity, the ability of a solution to conduct an electrical current, is associated with the presence of these mineral ions [14,31,42]. In our study, conductivity values remained almost constant throughout the season, with only a few points showing peaks at the beginning of the season. These could be related to a higher concentration of dissolved minerals in the sap. No significant difference in conductivity was observed between the two species, likely due to the fact that the trees are located on the same site and share similar climatic and environmental conditions. According to Lagacé [31], concentrations of cations (Ca, Na, Mg, and K) increase toward the end of the season. The difference with our study is that they worked with mixed sap, while our results are based on measurements from individual saps, which could explain the divergence observed in the trends.
Our results have significant implications in forest management, the maple syrup industry, and climate change adaptation strategies. Introducing red maple into sugarbushes could promote increased ecological diversity and enhance forest resilience to natural disturbances, particularly extreme climate events. For the maple syrup industry, red maple represents a strategic alternative in regions where sugar maple is less adapted or in which climate alterations could drive maladaptation. Due to its high adaptability to a wide range of environmental conditions, red maple could contribute to a more stable sap production.

5. Conclusions

Our study analyzed and compared the amount and quality of sap production between red maples and sugar maples growing in a sugar farm located at the northern border of maple distribution in Quebec, Canada. We were unable to detect differences in the physicochemical characteristics of sap between the two species. We estimated a longer sap period and a higher volume of sap produced by sugar maple during the sugar season. However, such differences need to be confirmed on a larger sample due to the huge variability observed between trees within the same species. Our results did not support the hypothesis of the greater performance of sugar maple in sap production compared to red maple. Investigating other metabolites, such as organic acids, phenolic compounds, and amino acids, could provide valuable insights to deepen the knowledge on the two species. Indeed, these molecules are known to interact during the thermal concentration process required for maple syrup production, leading to the formation of Maillard reaction products, which are responsible for the distinctive flavor of maple-derived products [10]. Our study provided valuable initial insight into sap production. Based on the actual knowledge and the results of this study, forest management in maple stands should primarily be guided by criteria related to the ecology of the species and their ability to adapt to the local conditions rather than on the potential performances in sap production. The presence of sugar maple and red maple within the same sugarbush could maintain diversity and ensure a higher resistance of the stand to natural disturbances.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/app15031091/s1, Figure S1: Map of stand location and species ranges.

Author Contributions

S.R. and S.L. conceived the ideas and designed the study; A.G. and S.Y.S.K. collected data; A.G. analyzed the data; A.G. and R.S. led the writing of the manuscript; S.Y.S.K., S.R., A.D. and S.L. contributed critically to the drafts. All authors have read and agreed to the published version of the manuscript.

Funding

This work was funded by the Natural Sciences and Engineering Research Council of Canada (research programs Alliance and Discovery grants ALLRP 555568—20 and ALLRP 597879—24), the Observatoire régional de recherche en forêt boréale, the Créneau d’excellence acéricole, Club acéricole du Sud du Québec, the Syndicat des producteurs des bois du Saguenay-Lac-Saint-Jean, the Producteurs et productrices acéricoles du Québec, and the Centre ACER.

Data Availability Statement

Data associated with this study are available on Borealis, the Canadian Dataverse at https://doi.org/10.5683/SP3/UE1SX9.

Acknowledgments

The authors thank S. Néron and A. Roussel, owners of the Érablière au Sucre d’Or, for permitting the study on their property; M. Ahmad Mslati for technical support; H. Dorion for map preparation; and A. Garside for the English correction of the manuscript.

Conflicts of Interest

The authors declare no conflicts of interest.

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Figure 1. Sap production in red maple and sugar maple during the 2023 sap season in Laterrière, QC, Canada.
Figure 1. Sap production in red maple and sugar maple during the 2023 sap season in Laterrière, QC, Canada.
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Figure 2. Cumulated sap production in red maple and sugar maple during the 2023 sap season in Laterrière, QC, Canada.
Figure 2. Cumulated sap production in red maple and sugar maple during the 2023 sap season in Laterrière, QC, Canada.
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Figure 3. Physicochemical characteristics of the sap harvested in red maple and sugar maple during the 2023 sap season in Laterrière, QC, Canada.
Figure 3. Physicochemical characteristics of the sap harvested in red maple and sugar maple during the 2023 sap season in Laterrière, QC, Canada.
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MDPI and ACS Style

Garfa, A.; Silvestro, R.; Sassamoto Kurokawa, S.Y.; Rossi, S.; Deslauriers, A.; Lavoie, S. Sugar Maple and Red Maple Face-Off: Which Produces More and Sweeter Sap? Appl. Sci. 2025, 15, 1091. https://doi.org/10.3390/app15031091

AMA Style

Garfa A, Silvestro R, Sassamoto Kurokawa SY, Rossi S, Deslauriers A, Lavoie S. Sugar Maple and Red Maple Face-Off: Which Produces More and Sweeter Sap? Applied Sciences. 2025; 15(3):1091. https://doi.org/10.3390/app15031091

Chicago/Turabian Style

Garfa, Aya, Roberto Silvestro, Sara Yumi Sassamoto Kurokawa, Sergio Rossi, Annie Deslauriers, and Serge Lavoie. 2025. "Sugar Maple and Red Maple Face-Off: Which Produces More and Sweeter Sap?" Applied Sciences 15, no. 3: 1091. https://doi.org/10.3390/app15031091

APA Style

Garfa, A., Silvestro, R., Sassamoto Kurokawa, S. Y., Rossi, S., Deslauriers, A., & Lavoie, S. (2025). Sugar Maple and Red Maple Face-Off: Which Produces More and Sweeter Sap? Applied Sciences, 15(3), 1091. https://doi.org/10.3390/app15031091

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