Comparison of Heat Transfer and Soil Impacts of Air Curtain Burner Burning and Slash Pile Burning
Abstract
:1. Introduction
- The ACB will produce a greater heat pulse and subsequently higher soil temperature profile within the mineral soil profile than SPB.
- A greater heat pulse associated with ACB will cause larger changes in soil chemical properties as compared to SPB.
- If the heat pulse between ACB and SPB is significant, then properties of wood ash generated by ACB would differ from those of SPB.
2. Methods
2.1. Study Sites and Burning Description
2.2. Soil and Ash Sampling
2.3. Soil Heat Transfer Measurement
2.4. Lab and Data Analyses
3. Results
3.1. Soil Heat Transfer
3.2. Change in Soil Properties
4. Discussion
5. Conclusions and Management Implications
- Since both ACB and SPB produce high burn temperatures close to the maximum for wood combustion, it is important to shorten the burn duration to prevent potential adverse ecological consequences associated with excessive heat. In terms of burning duration for a given amount of fuel, ACB is preferred to SPB because ACB has higher productivity than SPB.
- Wet and/or high OM content soils can provide some ameliorative qualities for reducing negative impacts of heat as compared to dry or low OM content soils. Thus, burning after rain over the ground with duff layer is recommended.
- If we extend our results to other sites, cold or arid regions may need to do post-burning amendments to provide for immediate vegetation recovery.
- Using wood ash as a fertilizer can ameliorate some potential negative impacts of burning on the mineral soil.
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Groveland Site | Volcano Site | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Small 1/Fresh | Mixed 2/Fresh | Mixed/Cured | Small/Fresh | Mixed/Fresh | ||||||
ACB | SPB | ACB | SPB | ACB | SPB | ACB | SPB | ACB | SPB | |
Air temperature (°C) | 23.8 | 20.1 | 30.2 | 24.4 | 19.4 | |||||
Relative Humidity (%) | 38.1 | 59.2 | 35.8 | 28.7 | 37.8 | |||||
Wind speed (km/h) | 1.8 | 1.5 | 0.3 | 0.8 | 0.5 | |||||
Soil moisture (%) | 13.7 | 18.1 | 17.0 | 16.2 | 9.6 | 8.7 | 6.7 | 7.4 | 9.2 | 9.5 |
Avg. Fuel size (diameter; cm) | 5.1 | 4.9 | 18.9 | 17.2 | 15.7 | 14.2 | 6.0 | 6.1 | 15.8 | 17.0 |
Fuel moisture contents (%) | 26.0 | 32.8 | 27.4 | 28.5 | 17.0 | 19.0 | 36.0 | |||
Fuel consumption 3 (ton) | 2.43 | 1.42 | 1.36 | 1.00 | 0.66 | 0.46 | 0.84 | 0.37 | 0.92 | 0.51 |
Max. temperature 4 (°C) | 1005 | 897 | 984 | 953 | 1026 | 1081 | 1080 | 1010 | 1055 | 1010 |
Total burning time (h) | 5.55 | 5.14 | 4.26 | 3.57 | 2.97 | 2.97 | 1.98 | 2.15 | 2.91 | 3.80 |
Model/Source | d.f. | MS | F-Statistic | p-Value |
---|---|---|---|---|
Peak temperature 1,2 | ||||
Burn method | 1 | 0.0765 | 0.585 | 0.446 |
Depth | 1 | 5.0555 | 38.647 | <0.001 |
Soil moisture | 1 | 4.1666 | 31.851 | <0.001 |
Lethal temperature duration 2 | ||||
Burn method | 1 | 7178 | 1.819 | 0.180 |
Depth | 1 | 183,170 | 46.407 | <0.001 |
Soil moisture | 1 | 85,878 | 21.758 | <0.001 |
Properties | Depth (cm) | Groveland | Volcano | ||||||
---|---|---|---|---|---|---|---|---|---|
Air Curtain Burner | Slash Pile Burning | Air Curtain Burning | Slash Pile Burning | ||||||
Pre-Burn | Post-Burn | Pre-Burn | Post-Burn | Pre-Burn | Post-Burn | Pre-Burn | Post-Burn | ||
OM contents (Mg ha−1) | 0–10 10–20 | 94.9 (4.2) 83.5 (5.1) | 102.8 (5.2) 87.0 (5.3) | 125.7 (4.4) 109.9 (4.6) | 114.3 (2.9) 125.3 (5.0) | 94.9 (11.2) 57.7 (4.8) | 56.1 (5.5) 75.6 (6.5) | 50.4 (4.5) 57.7 (4.5) | 58.7 (5.0) 63.5 (4.5) |
C contents (Mg ha−1) | 0–10 10–20 | 76.5 (3.8) 76.0 (4.4) | 88.2 (4.5) 78.2 (3.5) | 97.6 (3.9) 96.7 (3.3) | 99.1 (3.2) 112.3 (4.6) | 70.1 (6.5) 61.0 (4.3) | 63.5 (4.8) 85.0 (6.4) | 49.4 (3.0) 58.5 (3.8) | 56.7 (3.9) 63.1 (3.2) |
N contents (kg ha−1) | 0–10 10–20 | 690 (697) 564 (669) | 923 (845) 572 (726) | 1568 (618) 1027 (809) | 1374 (599) 1518 (652) | 41 (290) 0 (n.a.) | 133 (551) 43 (360) | 57 (403) 0 (n.a.) | 0 (n.a.) 0 (n.a.) |
Ca concentration (mg/kg) | 0–10 10–20 | 2524 (31) 2321 (35) | 2599 (35) 2021 (32) | 5373 (36) 3987 (48) | 5567 (37) 4614 (35) | 4770 (54) 3231 (41) | 4539 (53) 3884 (56) | 2738 (33) 1753 (26) | 2618 (39) 1797 (28) |
Mg concentration (mg/kg) | 0–10 10–20 | 251 (11) 197 (10) | 215 (9) 180 (9) | 398 (7) 337 (11) | 417 (8) 374 (7) | 99 (6) 83 (8) | 126 (8) 113 (9) | 67 (6) 47 (5) | 68 (6) 49 (5) |
K concentration (mg/kg) | 0–10 10–20 | 376 (16) 375 (16) | 429 (16) 378 (16) | 931 (16) 950 (24) | 867 (12) 721 (12) | 112 (8) 115 (6) | 152 (9) 145 (10) | 145 (9) 118 (7) | 135 (9) 108 (8) |
C concentration in ash (%) | - | - | 30.3 (4.6) | - | 35.3 (3.4) | - | 51.6 (4.6) | - | 65.6 (3.8) |
N concentration in ash (%) | - | - | 0.29 (0.30) | - | 0.29 (0.32) | - | 0.40 (0.37) | - | 0.47 (0.26) |
Ca concentration in ash (mg/kg) | - | - | 9333 (31) | - | 12187 (31) | - | 13221 (60) | - | 9566 (51) |
Mg concentration in ash (mg/kg) | - | - | 3471 (44) | - | 5364 (40) | - | 8080 (68) | - | 3356 (47) |
K concentration in ash (mg/kg) | - | - | 4376 (14) | - | 16125 (71) | - | 27338 (113) | - | 8594 (83) |
Property change (Δ) | Burn Method | Depth | Soil Moisture | Fuel Moisture | Fuel Type | Burn Time |
---|---|---|---|---|---|---|
OM contents (Mg ha−1) | 0.485 | 0.112 | 0.708 | 0.817 | 0.837 | 0.275 |
C contents (Mg ha−1) | 0.862 | 0.127 | 0.862 | 0.995 | 0.353 | 0.784 |
N contents (kg ha−1) | 0.599 | 0.289 | 0.469 | 0.937 | 0.175 | 0.482 |
Ca concentration (mg/kg) | 0.706 | 0.328 | 0.246 | 0.326 | 0.077 | 0.957 |
Mg concentration (mg/kg) | 0.678 | 0.436 | 0.013 | 0.564 | 0.921 | 0.198 |
K concentration (mg/kg) | 0.009 | 0.214 | 0.001 | 0.619 | 0.186 | 0.776 |
Property | Burn Method | Fuel Moisture | Fuel Type | Burn Time |
---|---|---|---|---|
C concentration (%) | 0.119 | 0.188 | 0.122 | 0.002 |
N concentration (%) | 0.289 | 0.126 | 0.257 | 0.009 |
Ca concentration (mg/kg) | 0.292 | 0.191 | 0.112 | 0.074 |
Mg concentration (mg/kg) | 0.116 | 0.553 | 0.103 | 0.221 |
K concentration (mg/kg) | 0.020 | 0.726 | 0.054 | 0.162 |
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Jang, W.; Page-Dumroese, D.S.; Han, H.-S. Comparison of Heat Transfer and Soil Impacts of Air Curtain Burner Burning and Slash Pile Burning. Forests 2017, 8, 297. https://doi.org/10.3390/f8080297
Jang W, Page-Dumroese DS, Han H-S. Comparison of Heat Transfer and Soil Impacts of Air Curtain Burner Burning and Slash Pile Burning. Forests. 2017; 8(8):297. https://doi.org/10.3390/f8080297
Chicago/Turabian StyleJang, Woongsoon, Deborah S. Page-Dumroese, and Han-Sup Han. 2017. "Comparison of Heat Transfer and Soil Impacts of Air Curtain Burner Burning and Slash Pile Burning" Forests 8, no. 8: 297. https://doi.org/10.3390/f8080297