Big Hole - USBGH001
Additional Site Information

Emily K. Heyerdahl, Richard F. Miller


Dating Method: Crossdated

Sample Storage Location: USDA Forest Service, Rocky Mountain Research Station, 
Fire Sciences Laboratory, 5775 US W Highway 10, Missoula, MT  59808

Reference: Heyerdahl, E.K., R.F. Miller, and R.A Parsons.  2006.  History of 
fire and Douglas-fir establishment in a savanna and sagebrush-grassland mosaic,
southwestern Montana, USA.  Forest Ecology and Management.  230: 107-118.

Abstract: Over the past century, trees have encroached into grass- and 
shrublands across western North America.  These include Douglas-fir trees 
(Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco) encroaching 
into mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana (Rydb.) 
Beetle) from stable islands of savanna in southwestern Montana.  Our objectives 
were to quantify the relative area occupied by mountain big sagebrush and 
grasslands versus Douglas-fir savanna in the Fleecer Mountains of southwestern 
Montana today and in the past, and to identify the historical role of fire and 
other factors in maintaining this distribution.  To do this, we reconstructed 
a multicentury history of tree establishment and surface fires from 1120 trees 
sampled on a grid of 50 plots over 1030 ha covering a modern mosaic of 
sagebrush-grasslands and Douglas-fir trees.  We compared these histories to 
time series of climate and land use, and to spatial variation in topography 
and soil moisture availability.  Beginning in the mid-1800s, Douglas-fir trees 
established in areas in which trees did not persist historically.  In 1855, 
less than half the plots (42%) had trees whereas today, most plots do (94%).  
This encroachment was synchronous with the cessation of frequent surface fires, 
likely caused by the advent of domestic livestock grazing, and perhaps by the 
start of several decades of relatively dry summers.  Douglas-fir savannas 
historically occurred on fire-safe sites more often than did sagebrush-grass.  
Our inference that frequent fire excluded Douglas-fir in the past was supported 
by the results of a simulation model of fire and associated vegetation 
dynamics.  In the continued absence of fire, mountain big sagebrush and 
grasslands in southwestern Montana are likely to become more homogeneous as 
Douglas-fir trees continue to encroach.

Individual Tree Information (plot ID, tree number, number of samples, number of samples dated, species, condition, UTM-E(NAD27, zone 12), UTM-N(NAD27, zone 12):
4C,40,1,1,Pseudotsuga menzeisii,live ,347758,5078067
4C,41,1,0,Pseudotsuga menzeisii,live,347767,5078075
4C,42,1,1,Pseudotsuga menzeisii,log,347739,5078052
4D,21,1,1,Pseudotsuga menzeisii,snag,348209,5078105
4D,40,1,1,Pseudotsuga menzeisii,live,348145,5078126
4D,41,1,1,Pseudotsuga menzeisii,live,348231,5078158
4D,42,1,0,Pseudotsuga menzeisii,live,348171,5078127
4I,40,1,1,Pseudotsuga menzeisii,live,350893,5077596
4K,1,1,1,Pseudotsuga menzeisii,stump,351673,5078068
4K,20,1,1,Pseudotsuga menzeisii,stump,351673,5078068
4K,22,1,1,Pseudotsuga menzeisii,stump,351673,5078068
5E,40,1,1,Pinus contorta,live,348783,5077675
5E,41,1,1,Pinus contorta,live,348749,5077688
5E,42,1,1,Pseudotsuga menzeisii,live,348755,5077579
5E,43,1,1,Pseudotsuga menzeisii,live,348837,5077556
5F,40,1,1,Pinus contorta,log,349222,5077649
5G,40,1,1,Pseudotsuga menzeisii,live,349715,5077514
5G,41,1,1,Pseudotsuga menzeisii,live,349697,5077954
5I,40,1,1,Pseudotsuga menzeisii,live,350510,5077321
5I,41,1,1,Pseudotsuga menzeisii,live,350519,5077382
5I,42,1,1,Pseudotsuga menzeisii,live,350521,5077378
5J,40,1,1,Pseudotsuga menzeisii,stump,351362,5077558
6B,40,1,1,Pseudotsuga menzeisii,stump,347176,5077095
6B,41,1,1,Pseudotsuga menzeisii,stump,347172,5077093
6B,42,1,1,Pseudotsuga menzeisii,stump,347243,5077103
6C,40,1,1,Pseudotsuga menzeisii,live,347644,5077017
6C,41,1,1,Pseudotsuga menzeisii,live,347631,5077032
6C,42,1,1,Pseudotsuga menzeisii,live,347701,5077033
6D,40,1,1,Pseudotsuga menzeisii,live,348166,5077019
6D,41,1,1,Pseudotsuga menzeisii,live,348144,5077089
6D,42,1,1,Pseudotsuga menzeisii,log,348175,5077097
6E,40,1,1,Pinus contorta,snag,348671,5077370
6F,40,1,1,Pseudotsuga menzeisii,snag,349415,5077077
6F,41,1,1,Pseudotsuga menzeisii,live,349403,5077089
6H,40,1,1,Pseudotsuga menzeisii,live,350224,5077042
6I,40,1,1,Pseudotsuga menzeisii,snag,350760,5077128
6I,41,1,1,Pseudotsuga menzeisii,snag,350751,5077176
6I,42,1,1,Pseudotsuga menzeisii,live,350732,5077007
6K,40,1,1,Pseudotsuga menzeisii,live,351703,5077093
6K,41,1,1,Pseudotsuga menzeisii,live,351715,5077114
6K,42,1,1,Pseudotsuga menzeisii,stump,351720,5077130
6K,43,1,1,Pseudotsuga menzeisii,stump,351738,5077038
7B,40,2,2,Pseudotsuga menzeisii,live,347157,5076535
7B,41,1,1,Pseudotsuga menzeisii,live,347182,5076535
7B,42,1,1,Pseudotsuga menzeisii,snag,347291,5076639
7C,42,1,1,Pseudotsuga menzeisii,live,347479,5076582
7C,43,1,1,Pseudotsuga menzeisii,log,347476,5076579
7C,44,1,1,Pseudotsuga menzeisii,snag,347520,5076595
7C,45,1,0,Pseudotsuga menzeisii,log,347651,5076584
7C,46,1,0,Pseudotsuga menzeisii,live,347643,5076596
7C,47,1,0,Pseudotsuga menzeisii,log,347849,5076345
7D,44,1,1,Pseudotsuga menzeisii,stump,348027,5076387
7D,45,1,1,Pseudotsuga menzeisii,stump,348079,5076467
7D,46,1,1,Pseudotsuga menzeisii,log,348132,5076456
7D,47,1,0,Pseudotsuga menzeisii,log,348204,5076623
7D,48,1,1,Pseudotsuga menzeisii,stump,348258,5076676
7D,49,1,1,Pseudotsuga menzeisii,stump,348247,5076700
7D,50,1,1,Pseudotsuga menzeisii,stump,348247,5076700
7E,40,2,0,Pseudotsuga menzeisii,log,348575,5076858
7E,41,1,1,Pseudotsuga menzeisii,live,348541,5076834
7E,42,1,1,Pseudotsuga menzeisii,log,348507,5076842
7F,40,1,0,Pseudotsuga menzeisii,snag,349169,5076741
7F,41,1,1,Pseudotsuga menzeisii,live,349175,5076584
7F,42,1,1,Pseudotsuga menzeisii,live,348875,5076919
7H,40,1,1,Pseudotsuga menzeisii,snag,350105,5076583
8C,40,1,1,Pseudotsuga menzeisii,log,347816,5075977
8C,41,2,2,Pseudotsuga menzeisii,log,347697,5076212
8C,42,1,1,Pseudotsuga menzeisii,log,347710,5076262
8C,43,1,1,Pseudotsuga menzeisii,log,347710,5076261
8D,40,2,2,Pseudotsuga menzeisii,log,348196,5076085
8D,41,1,1,Pseudotsuga menzeisii,log,348196,5076085
8D,42,1,1,Pseudotsuga menzeisii,live,348066,5075983
8D,43,1,1,Pseudotsuga menzeisii,live,348067,5075983
8F,40,1,1,Pseudotsuga menzeisii,stump,349259,5076322
8F,41,1,1,Pseudotsuga menzeisii,live,349252,5076320
8F,42,1,1,Pseudotsuga menzeisii,live,349256,5076264
8G,40,1,1,Pseudotsuga menzeisii,live,349580,5076348
8G,41,1,1,Pseudotsuga menzeisii,live,349569,5076305
8G,42,1,1,Pseudotsuga menzeisii,live,349563,5076303
8H,40,2,2,Pseudotsuga menzeisii,stump,350263,5076120
8H,41,1,1,Pseudotsuga menzeisii,live,350261,5076116
8H,42,1,1,Pseudotsuga menzeisii,live,350263,5076145
8H,43,1,1,Pinus contorta,snag,350264,5076220
8I,40,1,1,Pseudotsuga menzeisii,live,350641,5076148
8I,41,1,0,Pseudotsuga menzeisii,live,350657,5076182

Fire History Graphs: Fire History Graphs illustrate specific years when 
fires occurred and how many trees were scarred. They are available in both 
PDF and PNG formats. The graphs consist of 2 parts, both of which show the 
X axis (time line) at the bottom with the earliest year of information on 
the left and the latest on the right.
The Fire Index Plot is the topmost plot, and shows two variables: sample 
depth (the number of recording trees in each year) as a blue line along 
the left Y axis, compared with the percent trees scarred shown as gray bars 
along the right Y axis.
Below, the Fire Chronology Plot consists of horizontal lines representing
injuries by year on individual sampled trees. Symbols are overlain that 
denote the years containing the dendrochronologically-dated fire scars or
injuries. The sample ID of each tree is displayed to the right of each
line. The Composite Axis below represents the composite information from
all individual series. The symbols used to represent the fire scars or
injuries, and the filters used to determine the composite information,
are shown in the legend.
These graphs were created using the Fire History Analysis and Exploration
System (FHAES). See http://frames.nbii.gov/fhaes/ for more information.