Table 2 Descriptive statistics of central Pennsylvania (PA) based on (a) ≈1000 equally-spaced points within a rectangle around fire-scar record (FSR) locations and (b) conditions at FSR sites (n = 21)
Predictor or condition | Mean | Median | Minimum | Maximum | 25th percentile | 75th percentile | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ALL | ETF | NF | ALL | ETF | NF | ALL | ETF | NF | ALL | ETF | NF | ALL | ETF | NF | ALL | ETF | NF | |
(a) Based on ≈1000 equally-spaced points | ||||||||||||||||||
Distance to nearest town, 18th century (km) | 22.5 | 20.6 | 27.3 | 21.3 | 19.7 | 27.6 | 0.7 | 0.7 | 1.3 | 54.0 | 54.0 | 50.7 | 13.3 | 11.6 | 18.7 | 30.9 | 27.9 | 36.3 |
Mean distance to nearest town, 1701–1750 (km) | 63.6 | 59.7 | 73.0 | 66.3 | 60.9 | 72.0 | 16.5 | 16.5 | 42.4 | 102.1 | 102.1 | 101.2 | 52.3 | 46.4 | 67.0 | 76.0 | 74.2 | 79.3 |
Distance to nearest trail, 18th century (km) | 4.2 | 3.5 | 6.0 | 3.1 | 2.4 | 5.1 | 0.0 | 0.0 | 0.0 | 20.2 | 16.6 | 20.2 | 1.3 | 1.1 | 2.6 | 6.0 | 5.0 | 8.7 |
Distance to nearest fifth-order stream (km) | 5.7 | 5.8 | 5.4 | 4.7 | 4.7 | 4.7 | 0.0 | 0.0 | 0.0 | 24.0 | 24.0 | 17.6 | 2.1 | 1.9 | 2.4 | 8.3 | 8.7 | 7.9 |
Distance to nearest sixth-order stream (km) | 14.0 | 13.4 | 15.4 | 11.6 | 11.0 | 13.4 | 0.0 | 0.0 | 0.0 | 46.0 | 46.0 | 45.5 | 4.9 | 4.5 | 5.8 | 21.5 | 21.1 | 23.8 |
Mean annual temperature, 1895–1924 (°C) | 8.5 | 9.1 | 7.0 | 8.5 | 9.5 | 6.9 | 5.5 | 5.5 | 5.7 | 10.9 | 10.9 | 8.7 | 7.1 | 8.4 | 6.5 | 9.7 | 10.0 | 7.5 |
Mean annual precipitation, 1895–1924 (mm) | 970 | 959 | 997 | 965 | 946 | 1003 | 823 | 825 | 823 | 1217 | 1217 | 1140 | 924 | 916 | 972 | 1008 | 989 | 1030 |
TRI (m) | 11 | 9 | 15 | 8 | 7 | 14 | 0 | 0 | 2 | 56 | 35 | 56 | 4 | 4 | 7 | 15 | 12 | 22 |
VRM | 0.003 | 0.002 | 0.006 | 0.001 | 0.001 | 0.003 | 0.000 | 0.000 | 0.000 | 0.039 | 0.022 | 0.039 | 0.000 | 0.000 | 0.001 | 0.004 | 0.002 | 0.008 |
Mean TRI (m) | 11 | 9 | 15 | 10 | 9 | 15 | 1 | 1 | 5 | 27 | 23 | 27 | 8 | 7 | 12 | 14 | 12 | 18 |
Mean VRM | 0.003 | 0.002 | 0.005 | 0.002 | 0.002 | 0.005 | 0.000 | 0.000 | 0.001 | 0.013 | 0.008 | 0.013 | 0.001 | 0.001 | 0.004 | 0.004 | 0.003 | 0.007 |
Elevation (m) | 379 | 317 | 530 | 365 | 281 | 545 | 91 | 91 | 178 | 775 | 775 | 769 | 223 | 202 | 458 | 522 | 425 | 613 |
Mean wind speed (m s-1) | 3.1 | 3.1 | 3.2 | 3.0 | 3.0 | 3.1 | 0.8 | 1.3 | 0.8 | 7.6 | 7.6 | 6.3 | 2.4 | 2.4 | 2.3 | 3.6 | 3.5 | 3.8 |
Pyrophilic trees, circa 18th century (% of total) | 68% | 81% | 36% | 85% | 88% | 24% | 2% | 3% | 2% | 97% | 97% | 90% | 56% | 82% | 6% | 90% | 91% | 66% |
(b) Based on FSR site locations | ||||||||||||||||||
Distance to nearest town, 18th century (km) | 24.7 | 22.7 | 25.8 | 25.3 | 22.5 | 26.3 | 7.6 | 7.6 | 17.5 | 42.4 | 42.4 | 32.7 | 22.5 | 19.0 | 25.0 | 27.4 | 24.7 | 27.4 |
Mean distance to nearest town, 1701–1750 (km) | 61.3 | 59.3 | 62.6 | 60.1 | 54.9 | 60.2 | 32.0 | 32.0 | 56.2 | 95.7 | 95.7 | 75.3 | 56.2 | 48.5 | 57.7 | 71.3 | 73.1 | 62.2 |
Distance to nearest trail, 18th century (km) | 3.5 | 4.1 | 3.0 | 3.1 | 2.5 | 3.2 | 0.5 | 0.9 | 0.5 | 10.3 | 10.3 | 5.7 | 1.4 | 1.0 | 2.1 | 4.2 | 6.9 | 3.9 |
Distance to nearest fifth-order stream (km) | 3.6 | 4.6 | 3.0 | 2.6 | 2.9 | 2.6 | 0.6 | 1.2 | 0.6 | 11.3 | 11.3 | 5.8 | 1.7 | 1.8 | 1.7 | 3.7 | 5.6 | 3.7 |
Distance to nearest sixth-order stream (km) | 11.4 | 10.2 | 12.1 | 12.8 | 10.3 | 13.9 | 1.9 | 1.9 | 3.6 | 27.0 | 27.0 | 16.4 | 5.5 | 4.1 | 11.9 | 14.9 | 12.1 | 15.2 |
Mean annual temperature, 1895–1924 (°C) | 7.9 | 9.2 | 7.1 | 7.3 | 9.6 | 7.1 | 6.6 | 7.5 | 6.6 | 10.2 | 10.2 | 7.3 | 7.1 | 9.0 | 6.8 | 9.3 | 9.8 | 7.2 |
Mean annual precipitation, 1895–1924 (mm) | 940 | 996 | 905 | 913 | 978 | 886 | 827 | 913 | 827 | 1135 | 1135 | 1068 | 862 | 936 | 862 | 1023 | 1037 | 890 |
TRI (m) | 19 | 15 | 22 | 19 | 14 | 23 | 4 | 4 | 6 | 34 | 28 | 34 | 12 | 9 | 15 | 25 | 19 | 32 |
VRM | 0.008 | 0.007 | 0.009 | 0.007 | 0.005 | 0.008 | 0.001 | 0.001 | 0.002 | 0.023 | 0.019 | 0.023 | 0.005 | 0.003 | 0.006 | 0.009 | 0.009 | 0.009 |
Mean TRI (m) | 15 | 12 | 16 | 15 | 12 | 16 | 10 | 11 | 10 | 20 | 14 | 20 | 13 | 11 | 15 | 16 | 13 | 16 |
Mean VRM | 0.004 | 0.003 | 0.005 | 0.004 | 0.003 | 0.004 | 0.002 | 0.002 | 0.004 | 0.009 | 0.005 | 0.009 | 0.004 | 0.002 | 0.004 | 0.005 | 0.004 | 0.005 |
Elevation (m) | 554 | 510 | 581 | 555 | 480 | 585 | 402 | 402 | 521 | 649 | 649 | 637 | 521 | 439 | 536 | 625 | 578 | 625 |
Mean wind speed (m s-1) | 3.8 | 4.1 | 3.6 | 3.7 | 4.6 | 3.3 | 1.2 | 1.2 | 1.2 | 6.8 | 6.8 | 6.7 | 2.5 | 2.5 | 2.5 | 5.4 | 5.5 | 4.2 |
Pyrophilic trees, circa 18th century (% of total) | 51% | 88% | 29% | 35% | 91% | 19% | 8% | 73% | 8% | 96% | 96% | 80% | 19% | 87% | 19% | 90% | 92% | 35% |
Number of fires, 1701–1750 | 4.0 | 6.6 | 2.4 | 3.0 | 6.0 | 2.0 | 0.0 | 1.0 | 0.0 | 14.0 | 14.0 | 5.0 | 2.0 | 3.5 | 1.0 | 5.0 | 9.0 | 4.0 |
