Melissa Thomas-Van Gundy USDA Forest Service Northern Research Station Greg Nowacki USDA Forest Service Eastern Region WITNESS TREES AS PYRO-INDICATORS History of settlement and land clearing Old growth patches remaining may not be representative Patchy paleo record (pollen, charcoal, cave sediments) Do have witness trees FIRE HISTORIES FOR EASTERN FORESTS Metes and bounds 13 original colonies Irregular boundaries Towns and lots Public land surveys Rectangular (Township and Range) Land Ordinance of 1784 Northwest Ordinance of 1787 Witness trees as sample LAND SURVEY METHODS Monongahela National Forest (MNF) CREATING THE DATABASE 15,591 corners/22,107 trees MNF DATA About 30% date to 1850s MNF DATA 1850s 1870s trunk lines of B&O and C&O railroads complete 1880s WV&P line reaches Pickens 1884 WV Central & Pittsburgh line reaches Davis 1889 WVC&P line reaches Elkins 1899 WV&P line reaches terminus at Richwood 49 species total Relative frequency by subsection of top 7 graphed here MNF DATA DISTURBANCE REGIMES Pyrophilic Traits: Thick bark, sprouters, xerophytic, fire-encouraging leaves, early seral CaryaHickory CastaneaChestnut CornusDogwood JuniperusRed cedar, cedar NyssaBlackgum, gum PinusPine PopulusAspen, cottonwood QuercusOak RobiniaLocustSassafras AbiesBalsam fir, fir, balsam AcerMaple BetulaBirch Carpinus/OstryaHornbeam, ironwood FagusAmerican beech FraxinusAsh JuglansButternut, walnut LiriodendronYellow-poplar, tulip tree MagnoliaMagnolia, cucumber PiceaRed spruce, spruce, yew pine PlantanusSycamore Prunus Black or wild cherry SalixWillow TaxusYew TiliaBasswood, white lynn, lin TsugaHemlock, hemlock-spruce UlmusElm Pyrophobic Traits: Thin bark, shallow roots, mesophytic, fire-discouraging leaves, late seral Witness-tree categorization PERCENT PYROPHILIC WITNESS TREE SPECIES Category of witness tree point No. in study area No. of 1-tree points7,710 No. of 2-tree points5,451 No. of 3-tree points1,016 No. of 4-tree points131 No. of 5-tree points24 No. of 6-tree points4 Total no. of points14,336 No. of exclusively pyrophilic points 6,329 No. of mixed points2,109 No. of exclusively pyrophobic points 5,898 Total no. of points14,336 Witness-tree data ( surveys) Pyrophilic percentage = # of pyrophilic trees total # of trees * 100 Pyrophobic ptsPyrophilic pts Phobic over philic ptsPhilic over phobic pts Pyrophilic % corresponded to a climo- elevational gradient. Pyrophilic% with: elevation precipitation frost days temperature growing days EXPANDING TO OTHER AREAS ALLEGHENY NF FINGER LAKES NF GREEN MOUNTAIN NF WHITE MOUNTAIN NF Influence of Native Americans National ForestMean pyrophilic percentage Within 5 km of Native American sites Beyond 5 km of Native American sites P-value Allegheny < Finger Lakes < Green Mtn00NA White Mtn