This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain. POSTFIRE VEGETATIVE RESPONSE IN A WHITEBARK PINE COMMUNITY, BOB MARSHALL WILDERNESS, MONTANA Maria Ash and Richard J. Lasko On June 28, 1985, lightning ignited three small fires resprouted from surviving roots (table 1). Six percent on the ridge just west of Charlotte Peak in the Bob were onsite (residual) colonizers, plants which germinated Marshall Wilderness, MT. These three fires were man­ from seeds that were in existence either in the ground or aged collectively as the Charlotte Peak Prescribed Fire in tree crowns before the fire. Thirty-five percent were and were part of a program to restore fire to the Bob offsite colonizers, species which germinated from seeds Marshall Ecosystem. The Charlotte Peak fire burned that were brought to the plot by either animals or wind. nearly 5,400 acres before it was extinguished by heavy Six percent were of unknown origin. rains in late July and early August. One of the more notable offsite colonizers was Pinus A field study was initiated in the summer of 1986 for albicoulis. Since Pinus albicaulis has an indehiscent the purpose of measuring vegetative response to fire in cone, it is probable that seedlings were established from several different community types. A plot in a whitebark Clark's nutcracker seed caching. This most likely oc­ pine (Pinus albicaulis) community type was located near curred in 1987, since it was not until the third year (1988) the point of ignition, just below the main ridgeline west of that any conifer seedlings were noted (densities in 1986, Charlotte. Peak (Plot 114). 1987, and 1988 were 0, 0, and 264 seedlings per acre, The criteria for placing this plot were that the preburn respectively). It appears that cone crop production was community was a mature stand dominated by Pinus albi­ poor in 1985 and 1986 but good enough in 1987 to provide caulis and was completely consumed by fire. The plot was enough seeds to explain the 1988 surge in Pinus albicau­ permanently marked and has been remeasured annually lis seedlings. This was also true for Abies lasiocarpa, but since the fire (1986-1988). The study site is located at an since its seed dispersal mechanism is by wind from elevation of 7,320 fl; with an easterly aspect on a 40 per­ the nearest unburned area it appeared in much lower cent slope. The Montana Forest Habitat Type most densities. closely resembles Abies lasiocarpa I Luzula hitchcockii I Two other species of particular significance are Vaccinium scoparium, though postfire determination is Epilobium angustifolium and Carex rossii. Epilobium difficult. The preburn stand was approximately 195 years angustifolium's seeds are windblown onto the site after old with a mixed Pinus albicaulis and Abies lasiocarpa the fire, subsequently providing vegetative and litter overstory. cover. Carex rossii usually does not occur in the prefire stand vegetatively, but does in the form of a residual seed METHODS in the ground awaiting fire to create the proper germina­ tion conditions. Plot 114 was sampled using Ecodata Classification Canopy cover and vegetative production showed sig­ Sampling Methods. Species' frequencies and canopy cov­ nificant increases each year (figs. 1 and 2, respectively); erages were measured within 25 microplots on a lOth-acre however, nested rooted frequency (fig. 3) did not change macroplot. Ground cover and production by life form was significantly. This is primarily due to the fact that the also measured. Tree and shrub densities were measured plants with the highest coverages and densities were by age class. Other data were also taken for each species, resprouts, therefore not increasing in numbers of plants, including canopy coverage by age/size class, distribution, only in size in later years. Most of the plants present in phenology, height, and hedging class. postbum years 1 through 3 became established in year 1 with very little colonization occurring in subsequent RESULTS years. Only four new species with very little cover were It was observed that, even though a stand-replacing recorded after year 1: Tragopogon dubius, Epilobium fire occurred, fire severity was low due to (1) low mineral watsonii, Abies lasiocarpa, and Pinus albicaulis. Three soil (1 to 5 percent) and high litter and duff (85 to 95 per­ species displayed a sporadic occurrence pattern, occurring cent) ground coverages, and (2) the high number of spe­ in one year and not the next. This is probably due to the cies that resprouted, including XerophyUum tenax, which inability to locate every single plant on the lOth-acre plot has a rhizome highly susceptible to severe fires. This low each year. These species were Senecio triangularis, fire severity influenced the types of species that returned. Pyrola secunda, and Viola orbiculata. In plot 114, 53 percent of the species found after the fire Maria Ash is Biological Technician and Richard J. Lasko is Resoun:e Assistant, Spotted Bear Ranger District, Flathead National Forest, Forest Service, U.S. Department of Agriculture, Hungry Horse, MT 59919. 360 Table 1-Survival strategies for plant species occurring on plot 11 4 Onslte colonizer Offslte colonizer Resprout Unknown origin Carex rossii Abies lasiocarpa Menziesia ferruginea Viola orbiculata Pinus albicaulis Vaccinium globulare Epilobium angustifolium Vaccinium scoparium Epilobium watsonii Luzula hitchcockii Hieracium albiflorum Arnica latifo/ia Tragopogon dubius Pedicularis racemosa Pyrola secunda Senecio triangularis Xerophyllum tenax 20 100 ~-----------------, CJ L. hitchcockii 90 E2l L. hitchcockii 111111 V. scoparium miD V. scoparium 16 80 15 • X. te nax • X. tenax 70 1- z !z 60 w w 50 0 50 a:0 10 a: w n. ~ 40 30 5 20 10 0 ....L...-----1""""- 1986 1987 1988 1986 1987 YEAR YEAR Figure 1-Canopy cover for Luzula hitchcockii, Figure 3-Nested rooted frequency for Luzu/a Vaccinium scoparium, and Xerophyllum tenax on hitchcock.ii, Vaccinium scoparium, and Xero­ plot 114 from 1986 to 1988. phyllum tenax on plot 114 from 1986 to 1988. 3000 II] Graminoid 2500 mml Forb • Shrub 2500 w a: 0 ._ct 1500 a:l ...J 1000 500 0 1986 1987 1988 YEAR Figure 2-Total production for Luzula hitchcockii, Vaccinium scoparium, and Xerophyl/um tenax on plot 114 from 1986 to 1988. 361 RELATIONSHIPS BETWEEN WHITEBARK PINE CONE PRODUCTION AND FALL GRIZZLY BEAR MOVEMENTS Bonnie M. Blanchard Whitebark pine (Pinus albicaulis) nuts are an impor­ matured approximately 2 weeks earlier than normal, tant and preferred food for Yellowstone grizzly bears probably due to favorable spring "weather conditions; and (Ursus arctos horribilis). Bears will consume these nuts transects were on the average read later than was ideal. to the near exclusion of other food items when they are Also, production was spotty that year and apparently available in sufficient quanticy. High fat content of the poorest in xeric, pure to nearly pure whitebark pine nuts can supply the calories needed to accumulate critical stands. The majority of transects were in those types fat reserves during fall in preparation for hibernation. In of stands, and cones were often noted on trees outside years of exceptional production, nuts will also be con­ transects. This prompted the establishment of additional sumed in the spring and summer of the following year. transects in mesic, mixed species stands previously To monitor annual cone production and subsequent unmonitored. availability of nuts to grizzly bears, 90-m transects of 10 Low amounts of nuts were consumed by grizzly bears trees each were established in whitebark pine stands until the mean number of cones per transect approached throughout the study area: nine in 1980, eight in 1987, 200. Red squirrels and Clark's nutcrackers were probably and two in 1988. Cones were counted in July and early able to consume nuts produced up to that level prior to August before appreciable harvesting by red squirrels caching of excess cones and nuts. Since grizzly bears (Tamiasciurus hudsonicus) and Clark's nutcrackers obtained nuts primarily by raiding squirrel caches, this CNucifraga columbiana) had begun. food source was largely unavailable until production ap­ proached 200 cones per transect. Above that level, the PRODUCTION-CONSUMPTION amount of pine nuts consumed would theoretically in­ crease with production until bears had maximized con­ Generally a significant relationship existed between sumption and extra cones would not be used that fall. cone production on transects and frequency of nuts in Maximized consumption was apparently reached in scats deposited during fall (September to November) 1985 when frequency of nuts was 0.81 in all fall scats and when the scat sample was more than 15 (fig. 1). An 1.00 in October scats alone (n =9). Maximum cone pro­ exception was 1987 when the transects failed to reflect duction on one transect was 625. A main diet item the fol­ actual cone availability for two primary reasons. Cones lowing spring and summer was whitebark pine nuts­ those remaining in caches from the fall of 1985. Fre­ quency of nuts in scats increased from 0.06 in May (n =32) to 0.29 in July (n =154), compared to the 1979 to 1987 average frequency of 0.17 in May and 0.19 in July. 1.00 ...,.-------------------. y cs-o.sas + 0.15 (1o-7 )x4 - ,------ ALTERNATE SOURCES rc0.90 ./' 0.80- P<O.OS When whitebark pine nuts were unavailable to grizzly - bears, they sought alternate food sources, often associated with human activities. A significant correlation existed >- 0.60- • M - 1987 I I• between mean number of cones produced per transect and a numbers of grizzly bears trapped in management actions w 0.40 I after August 1 for 1980 to 1986 (,-2 =-0.815, p < 0.05) IE - (fig.