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Table 4 Average soil temperatures, heat dosage, and severity for prescribed burns conducted in South Puget Sound, Washington, USA, prairies. All codes for the site listings are detailed in Table 1.

From: Prescribed Fire in Grassland Butterfly Habitat: Targeting Weather and Fuel Conditions to Reduce Soil Temperatures and Burn Severity

2014 burn date Site Time of ignition (hours) Burn length (min) Peak soil temp. (°C) Lethal heat dose a (°C * log[min]) Quadrats with lethal heat dose (n) Unburned or scorched area cover (%)
22 Jul LW 0942 33 22.7 0.00 0 25.5
22 Jul LW 1341 11 27.4 0.00 0 5.1
5 Aug TA6 0908 35 28.3 0.17 1 18.4
5 Aug TA6 1430 9 54.8 9.42 14 0.0
7 Aug JP 0804 27 25.1 0.00 0 4.1
7 Aug JP 0920 20 29.3 0.20 1 0.0
7 Aug JP 1400 20 47.3 6.96 11 0.0
7 Aug JP 1501 9 41.2 1.59 8 0.0
15 Aug UW 1238 28 27.6 0.00 0 25.5
18 Aug TA15 0858 32 22.1 0.00 0 94.9
18 Aug TA15 1002 20 26.9 0.00 0 43.9
18 Aug TA15 1534 37 47.2 10.45 11 16.3
18 Aug TA15 1716 20     5.1
19 Aug UW 1632 15 40.4 1.74 8 13.3
25 Aug SW 0900 28 24.4 0.00 0 18.4
25 Aug SW 1505 13 41.9 2.73 9 15.3
15 Sep GH 1014 20 34.5 1.24 2 42.9
15 Sep GH 1230 12 45.2 3.09 6 6.1
18 Sep TQ 1331 53 23.4 0.00 0 92.9
22 Sep TQ 1600 17     17.4
   Minimum 9 22.1 0.00 0 0.0
   Mean 23 33.9 2.09 4 22.3
   Maximum 37 54.8 10.45 14 94.9
  1. a Lethal heat dosage calculated as the area under the temperature-time curve but above the TDT curve