International Journal of Wildland Fire International Journal of Wildland Fire Society
Journal of the International Association of Wildland Fire
RESEARCH ARTICLE

Holocene vegetation and fire regimes in subalpine and mixed conifer forests, southern Rocky Mountains, USA

R. S. Anderson A F , C. D. Allen B , J. L. Toney C D , R. B. Jass C E and A. N. Bair C
+ Author Affiliations
- Author Affiliations

A Center for Environmental Sciences and Quaternary Sciences Program, Northern Arizona University, Flagstaff, AZ 86011, USA.

B US Geological Survey, Jemez Mountains Field Station, Los Alamos, NM 87544, USA.

C Quaternary Sciences Program, Northern Arizona University, Flagstaff, AZ 86011, USA.

D Present address: Department of Geological Sciences, Brown University, 324 Brook Street, Providence, RI 02912, USA.

E Present address: 4014A Lewis Lane, Austin, TX 78756, USA.

F Corresponding author. Email: scott.anderson@nau.edu

International Journal of Wildland Fire 17(1) 96-114 https://doi.org/10.1071/WF07028
Submitted: 14 February 2007  Accepted: 15 November 2007   Published: 15 February 2008

Abstract

Our understanding of the present forest structure of western North America hinges on our ability to determine antecedent forest conditions. Sedimentary records from lakes and bogs in the southern Rocky Mountains of Colorado and New Mexico provide information on the relationships between climate and vegetation change, and fire history since deglaciation. We present a new pollen record from Hunters Lake (Colorado) as an example of a high-elevation vegetation history from the southern Rockies. We then present a series of six sedimentary records from ~2600 to 3500-m elevation, including sites presently at the alpine–subalpine boundary, within the Picea engelmanniiAbies lasiocarpa forest and within the mixed conifer forest, to determine the history of fire in high-elevation forests there. High Artemisia and low but increasing percentages of Picea and Pinus suggest vegetation prior to 13 500 calendar years before present (cal yr BP) was tundra or steppe, with open spruce woodland to ~11 900 cal yr BP. Subalpine forest (Picea engelmannii, Abies lasiocarpa) existed around the lake for the remainder of the Holocene. At lower elevations, Pinus ponderosa and/or contorta expanded 11 900 to 10 200 cal yr BP; mixed conifer forest expanded ~8600 to 4700 cal yr BP; and Pinus edulis expanded after ~4700 cal yr BP. Sediments from lake sites near the alpine–subalpine transition contained five times less charcoal than those entirely within subalpine forests, and 40 times less than bog sites within mixed conifer forest. Higher fire episode frequencies occurred between ~12 000 and 9000 cal yr BP (associated with the initiation or expansion of south-west monsoon and abundant lightning, and significant biomass during vegetation turnover) and at ~2000–1000 cal yr BP (related to periodic droughts during the long-term trend towards wetter conditions and greater biomass). Fire episode frequencies for subalpine–alpine transition and subalpine sites were on average 5 to 10 fire events/1000 years over the Holocene, corresponding to one fire event every ~100 to 200 years. (5) Our Holocene-length sedimentary charcoal records provide additional evidence for the anomalous nature of the 20th-century fire regime, where fires were largely suppressed as a national policy.

Additional keywords: fire history, paleoecology, pollen analysis.


Acknowledgements

We thank Mark Daniels, John Hogan, Chris Jass, Amy Kelly, Emily Moss, and M. Scott Wiggers for field assistance; Caitilin McCracken and Heather Atkins for pollen processing; Douglas Hallett for assistance with charcoal data manipulation; Kay Beeley for additional data manipulation; Richard Ku for producing the 210Pb and 137Cs ages; Tom Swetnam for financial assistance with some of the radiocarbon dates; Kirsten Ironside for Fig. 1; and Victor Leshyk for drafting several other figures. We also thank Cathy Whitlock and an anonymous reviewer for their insightful, and very helpful, comments, and Julio Betancourt for his comments. Funding was provided by the USGS Grants 1445-0009-94-1069, 99CRAG0019, and 04CRAG0033. Laboratory of Paleoecology Contribution Number 100.


References


Adams DK , Comrie AC (1997) The North American monsoon. Bulletin of the American Meteorological Society  78(10), 2197–2213.
CrossRef |

Alington C (1998) Fire history and landscape pattern in the Sangre de Cristo Mountains, Colorado. PhD Thesis, Colorado State University, Fort Collins.

Allen CD (2004) Ecological patterns and environmental change in the Bandelier landscape. In ‘Village formation on the Pajarito Plateau, New Mexico’. (Ed. TA Kohler) pp. 19–68. (University of New Mexico Press: Albuquerque, NM)

Allen CD, Anderson RS, Jass RB, Toney JT , Baisen CH (2008) Paired charcoal and tree-ring records of high-frequency Holocene fire from two New Mexico bog sites. International Journal of Wildland Fire  17, 115–130.
CrossRef |

Anderson RS (1989) Development of the southwestern ponderosa pine forests – what do we really know? USDA Forest Service, Forest Range Experiment Station General Technical Report 185. (Rocky Mountain, CO) pp. 15–22.

Anderson RS (1993) Mid- and late Wisconsin paleoclimates and environments near Potato Lake, Arizona. Quaternary Research  40, 351–359.
CrossRef |

Anderson RS, Hasbargen J, Koehler PA , Feiler EJ (1999) Late Wisconsin and Holocene Subalpine Forests of the Markagunt Plateau of Utah, Southwestern Colorado Plateau, U.S.A. Arctic, Antarctic, and Alpine Research  31, 367–378.
CrossRef |

Anderson RS, Betancourt JL, Mead JI, Hevly RH , Adam DP (2000) Middle and late-Wisconsin paleobotanic and paleoclimatic records from the southern Colorado Plateau, USA. Palaeogeography, Palaeoclimatology, Palaeoecology  155, 31–57.
CrossRef |

Anderson RS, Allen CD, Toney JL, Jass RB , Bair AN (2004) Holocene vegetation and forest fire regimes in subalpine and mixed conifer forests, southern Colorado and northern New Mexico, USA. Polen  14, 220.


Anderson RS, Hallett DJ, Berg E, Jass RB, Toney JL, de Fontaine CS , DeVolder A (2006) Holocene development of boreal forests and fire regimes on the Kenai Lowlands of Alaska. The Holocene  16(6), 791–803.

CrossRef |

Anderson RS, Jass RB, Toney JL, Allen CD, Cisneros-Dozal M, Hess M, Heikoop J , Fessenden J (in press) Development of the mixed-conifer forest in northern New Mexico, and its relationship to Holocene climate change. Quaternary Research ,


Appleby PG (2001) Chronostratigraphic techniques in recent sediments. In ‘Tracking environmental change using lake sediments. Volume 1: basin analysis, coring, and chronological techniques’. (Eds WM Last, JP Smol) pp. 171–203. (Kluwer Academic Publishers: Dordrecht)

Armour J, Fawcett PJ , Geissman JW (2002) 15 k.y. paleoclimatic and glacial record from northern New Mexico. Geology  30(8), 723–726.
CrossRef |

Bair AN (2004) A 15000 year vegetation and fire history record, southern Sangre de Cristo Mountains, New Mexico. MS Thesis, Northern Arizona University, Flagstaff.

Benson L, Madole R, Phillips W, Landis G, Thomas T , Kubik P (2004) The probable importance of snow and sediment shielding on cosmogenic ages of north-central Colorado Pinedale and pre-Pinedale moraines. Quaternary Science Reviews  23, 193–206.
CrossRef |

Benson L, Madole R, Landis G , Gosse J (2005) New data for Late Pleistocene Pinedale alpine glaciation from southwestern Colorado. Quaternary Science Reviews  24, 49–65.
CrossRef |

Betancourt JL (1990) Late Quaternary biogeography of the Colorado Plateau. In ‘Packrat middens: the last 40000 years of vegetation change’. (Eds JL Betancourt, TR Van Devender, PS Martin) pp. 259–292. (University of Arizona Press: Tucson, AZ)

Binkly G (2003) Returning fire to the forest. Fire and Fuels in Southwest Colorado  3, 4–6.


Biswell HH (1989) ‘Prescribed burning in California wildland vegetation management.’ (University of California Press: Berkeley, CA)

Breshears DD, Cobb NS, Rich PM, Price KP , Allen CD (2005) Regional vegetation die-off in response to global-change-type drought. Proceedings of the National Academy of Sciences of the United States of America  102(42), 15144–15148.
CrossRef | PubMed |

Briles CE, Whitlock C , Bartlein PJ (2005) Post-glacial vegetation, fire, and climate history of the Siskiyou Mountains, Oregon, USA. Quaternary Research  64, 44–56.
CrossRef |

Brown RT, Agee JK , Franklin JF (2004) Forest restoration and fire: principles in the context of place. Conservation Biology  18, 903–912.
CrossRef |

Brugger KA (2007) Cosmogenic 10Be and 36Cl ages from Late Pleistocene terminal moraine complexes in the Taylor River drainage basin, central Colorado, USA. Quaternary Science Reviews  26, 494–499.
CrossRef |

Brunelle A , Anderson RS (2003) Sedimentary charcoal as an indicator of late-Holocene drought in the Sierra Nevada, California, and its relevance to the future. The Holocene  13(1), 21–28.
CrossRef |

Brunelle A , Whitlock C (2003) Post-glacial fire, vegetation, and climate history in the Clearwater Range, Northern Idaho, USA. Quaternary Research  60, 307–318.
CrossRef |

Brunelle A, Whitlock C, Bartlein P , Kipfmueller K (2005) Holocene fire and vegetation along environmental gradients in the Northern Rocky Mountains. Quaternary Science Reviews  24, 2281–2300.
CrossRef |

Brunner-Jass RM (1999) Fire occurrence and paleoecology at Alamo Bog and Chihuahueños Bog, Jemez Mountains, New Mexico, USA. MS Thesis, Northern Arizona University, Flagstaff.

Carrara P, Trimble D , Rubin M (1991) Holocene treeline fluctuations in the northern San Juan Mountains, Colorado, USA as indicated by radiocarbon-dated conifer wood. Arctic and Alpine Research  23, 233–246.
CrossRef |

Carrara PE, Mode WN, Rubin M , Robinson SW (1984) Deglaciation and post-glacial timberline in the San Juan Mountains, Colorado. Quaternary Research  21, 42–55.
CrossRef |

Cole KL (1990) Reconstruction of past desert vegetation along the Colorado River using packrat middens. Palaeogeography, Palaeoclimatology, Palaeoecology  76, 349–366.
CrossRef |

Davis OK , Shafer DS (1992) A Holocene climatic record for the Sonoran Desert from pollen analysis of Montezuma Well, Arizona, USA. Palaeogeography, Palaeoclimatology, Palaeoecology  92, 107–119.
CrossRef |

Dick-Peddie WA (1993) ‘New Mexico vegetation, past, present, and future.’ (University of New Mexico Press: Albuquerque, NM)

Dixon HN (1962) Vegetation, pollen rain and pollen preservation, Sangre de Cristo Mountains, New Mexico. MS Thesis, University of New Mexico, Albuquerque, NM.

Elias S, Carrara P, Toolin L , Jull A (1991) Revised age of deglaciation of Lake Emma based on new radiocarbon and macrofossil analyses. Quaternary Research  36, 307–321.
CrossRef |

Fall PL (1992) Pollen accumulation in a montane region of Colorado, USA: a comparison of moss polsters, atmospheric traps, and natural basins. Review of Palaeobotany and Palynology  72, 169–197.
CrossRef |

Fall PL (1997) Fire history and composition of the subalpine forest of western Colorado during the Holocene. Journal of Biogeography  24, 309–325.
CrossRef |

Fægri K, Iversen J (1989) ‘Textbook of pollen analysis.’ 4th edn. (John Wiley and Sons: Chichester, UK)

Feiler EJ, Anderson RS , Koehler PA (1997) Late Quaternary paleoenvironments of the White River Plateau, Colorado, USA. Arctic and Alpine Environments  29, 53–62.
CrossRef |

Floyd-Hanna L, Spencer AW, Romme WH (1996) Biotic communities of the semiarid foothills and valleys. In ‘The Western San Juan Mountains: their geology, ecology and human history’. (Ed. R Blair) pp. 143–158. (University Press of Colorado: Niwot, CO)

Forman SL, Goetz AFH , Yuhas RH (1992) Large-scale stabilized dunes on the High Plains of Colorado: understanding the landscape response to Holocene climates with the aid of images from space. Geology  20, 145–148.
CrossRef |

Forman SL, Spaeth M, Marín L, Pierson J, Gómez J, Bunch F , Valdez A (2006) Episodic Late Holocene dune movements on the sand-sheet area, Great Sand Dunes National Park and Preserve, San Luis Valley, Colorado, USA. Quaternary Research  66, 97–108.
CrossRef |

Foxx TS, Tierney GD (1985) ‘Status of the flora of the Los Alamos National Environmental Research Park. Checklist of vascular plants of the Pajarito Plateau and Jemez Mountains. Volume 3.’ (Los Alamos National Laboratory, LA-8050-NERP: Los Alamos, NM)

Friddell JE, Thunell RC, Guilderson TP , Kashgarian M (2003) Increased north-east Pacific climatic variability during the warm middle Holocene. Geophysical Research Letters  30(11), 1560.
CrossRef |

Friedman I, Carrara P , Gleason J (1988) Isotopic evidence of Holocene climatic change in the San Juan Mountains, Colorado. Quaternary Research  30, 350–353.
CrossRef |

Grimm EC (1987) CONISS: a Fortran 77 program for stratigraphically constrained cluster analysis by the method of incremental sum of squares. Computers & Geosciences  13, 13–35.
CrossRef |

Grimm E (1993) ‘Tilia and Tilia Graph Versions 2.0.b.4.’ (Illinois State Museum, Research and Collections Center: Springfield, IL)

Grissino-Mayer HD (1996) A 2129-year reconstruction of precipitation for north-western New Mexico, USA. In ‘Tree rings, environment and humanity’. (Eds JS Dean, DM Meko, TS Swetnam) pp. 191–204. (University of Arizona Press: Tucson, AZ)

Heyerdahl EK, Brubaker LB , Agee JK (2002) Annual and decadal climate forcing of historical fire regimes in the interior Pacific North-west, USA. The Holocene  12(5), 597–604.
CrossRef |

Holmgren CA, Norris J , Betancourt JL (2007) Inferences about winter temperatures and summer rains from the late Quaternary record of C4 perennial grasses and C3 desert shrubs in the northern Chihuahuan Desert. Journal of Quaternary Science  22(2), 141–161.
CrossRef |

Hu FS, Brubaker LB, Gavin DG, Higuera PE, Lynch JA, Rupp TS , Tinner W (2006) How climate and vegetation influence the fire regime of the Alaskan boreal-forest biome: the Holocene perspective. Mitigation and Adaptation Strategies for Global Change  11, 829–846.
CrossRef |

Jacobs BF (1985) A middle Wisconsin pollen record from Hay Lake, Arizona. Quaternary Research  24, 121–130.
CrossRef |

Jamieson DW, Romme WH, Somers P (1996). Biotic communities of the cool mountains. In ‘The Western San Juan Mountains: their geology, ecology and human history’. (Ed. R Blair) pp. 159–174. (University Press of Colorado: Niwot, CO)

Jodry MA, Shafer DS, Stanford DJ, Davis OK (1989) Late Quaternary environments and human adaptation in the San Luis Valley, south-central Colorado. In ‘Colorado Ground-Water Association Guidebook, 8th Annual Field Trip’. pp. 189–208. (Colorado Ground-Water Association: Lakewood, CO)

Kipfmueller KF , Baker WL (2000) A fire history of a subalpine forest in south-eastern Wyoming, USA. Journal of Biogeography  27, 71–85.
CrossRef |

Kutzbach JE , Guetter PJ (1986) The influence of changing orbital parameters and surface boundary conditions on climate simulations for the past 18 000 years. Journal of the Atmospheric Sciences  43(16), 1726–1759.
CrossRef |

Leopold SA, Cain S, Cottam CA, Gabrielson IN, Kimball TL (1963) Wildlife management in the national parks. American Forestry 69, 32–35, 61–63.

Long CJ, Whitlock C, Bartlein PJ , Millspaugh SH (1998) A 9000-year fire history from the Oregon Coast Range, based on a high-resolution charcoal study. Canadian Journal of Forest History  28, 774–787.
CrossRef |

Lotan JE, Critchfield WB (1990) Pinus contorta Dougl. Ed. Loud. In ‘Silvics of North America, Volume 1, Conifers’. (Eds RM Burns, BH Honkala) pp. 302–315. USDA Forest Service, Agriculture Handbook 654. (Washington, DC)

Lynch JA, Clark JS, Bigelow NH, Edwards ME , Finney BF (2003) Geographic and temporal variations in fire history in boreal ecosystems of Alaska. Journal of Geophysical Research  108(D1), 8152.

CrossRef |

Lynch JA, Hollis JL , Hu FS (2004) Climatic controls of the boreal-forest fire regime: Holocene records from Alaska. Journal of Ecology  92, 477–489.
CrossRef |

Madole RF (1994) Stratigraphic evidence of desertification in the west-central Great Plains within the past 1000 yr. Geology  22, 483–486.
CrossRef |

Madole RF (1995) Spatial and temporal patterns of late Quaternary eolian deposition, eastern Colorado, USA. Quaternary Science Reviews  14, 155–177.
CrossRef |

Maher L (1961) Pollen analysis and post-glacial vegetation history in the Animas Valley region, southern San Juan Mountains, Colorado. PhD Thesis, University of Minnesota, USA.

Margolis EQ, Swetnam TW , Allen CD (2007) A stand-replacing fire history in upper montane forests of the Southern Rocky Mountains. Canadian Journal of Forest Research  37, 2227–2241.
CrossRef |

Markgraf V , Scott L (1981) Lower timberline in central Colorado during the past 15000 years. Geology  9, 231–234.
CrossRef |

Marlon J, Bartlein PJ , Whitlock C (2006) Fire–fuel–climate linkages in the north-western USA during the Holocene. The Holocene  16, 1059–1077.
CrossRef |

Menking KM , Anderson RY (2003) Contributions of La Niña and El Niño to middle Holocene drought and late Holocene moisture in the American Southwest. Geology  31(11), 937–940.
CrossRef |

Millspaugh SH , Whitlock C (1995) A 750-year fire history based on lake sediment records in central Yellowstone National Park, USA. The Holocene  5, 283–292.
CrossRef |

Mock CJ (1996) Climatic controls and spatial variations of precipitation in the western United States. Journal of Climate  9, 1111–1125.
CrossRef |

Moy CM, Seltzer GO, Rodbell DT , Anderson DM (2002) Variability of El Niño/Southern Oscillation activity at millennial timescales during the Holocene epoch. Nature  420(6912), 162–165.
CrossRef | PubMed |

Mueller RC, Scudder CM, Porter ME, Trotter RT, Gehring CA , Whitham TG (2005) Differential tree mortality in response to severe drought: evidence for long-term vegetation shifts. Journal of Ecology  93, 1085–1093.
CrossRef |

Muhs DR, Stafford TW, Cowherd SD, Mahan SA, Kihl R, Maat PB, Bush CA , Nehring J (1996) Origin of the late Quaternary dune fields of north-eastern Colorado. Geomorphology  17, 129–149.
CrossRef |

NIFC (2008) Fire information. Wildland Fire Statistics. Available at http://www.nifc.gov/fire_info/fires_acres.htm [Verified 21 January 2008]

Parsons DJ , DeBendeetti SH (1979) Impact of fire suppression on a mixed-conifer forest. Forest Ecology and Management  2, 21–33.
CrossRef |

Petersen KL (1981) 10000 years of climatic change reconstructed from fossil pollen, La Plata Mountains, Southwestern Colorado. PhD Dissertation, Washington State University, Pullman.

Petersen KL (1985) Palynology in Montezuma County, Southwestern Colorado: the local history of pinyon pine (Pinus edulis). In ‘Late Quaternary palynology of the American SouthWest’. (Eds BF Jacobs, OK Davis, P Fall) pp. 47–62. (American Association of Stratigraphic Palynologists Foundation: Dallas, TX)

Petersen KL , Mehringer PJ (1976) Post-glacial timberline fluctuations, La Plata Mountains, southwestern Colorado. Arctic and Alpine Research  8, 275–288.
CrossRef |

Polyak VJ , Asmerom Y (2001) Late Holocene climate and cultural changes in the southwestern United States. Science  294(5540), 148–151.
CrossRef | PubMed |

Polyak VJ, Cokendolpher JC, Norton RA , Asmerom Y (2001) Wetter and cooler late Holocene climate in the southwestern United States from mites preserved in stalagmites. Geology  29(7), 643–646.
CrossRef |

Pyne SJ (1982) ‘Fire in America: a cultural history of wildland and rural fires.’ (Princeton University Press: Princeton, NJ)

Rasmussen JBT, Polyak VJ , Asmerom Y (2006) Evidence for Pacific-modulated precipitation variability during the late Holocene from the southwestern USA. Geophysical Research Letters  33, L08701.
CrossRef |

Reasoner MA , Jodry MA (2000) Rapid response of alpine timberline vegetation to the Younger Dryas climate oscillation in the Colorado Rocky Mountains, USA. Geology  28(1), 51–54.
CrossRef |

Rein B, Lückge A, Reinhardt L, Sirocko F, Wolf A , Dullo W-C (2005) El Niño variability off Peru during the last 22000 years. Paleoceanography  20, PA4003.
CrossRef |

Salzer MW , Kipfmueller RS (2005) Reconstructed temperature and precipitation on a millennial timescale from tree-rings in the southern Colorado Plateau, USA. Climatic Change  70, 465–487.
CrossRef |

Shafer DS (1989) The timing of Late Quaternary monsoon precipitation maxima in the southwest United States. PhD Dissertation, University of Arizona, USA.

Sherriff RL, Veblen TT , Sibold JS (2001) Fire history in high elevation subalpine forests in the Colorado Front Range. Ecoscience  8(3), 369–380.


Sjostrom DJ, Hren MT , Chamberlain CP (2004) Oxygen isotope records of goethite from ferricrete deposits indicate regionally varying Holocene climate change in the Rocky Mountain region, USA. Quaternary Research  61, 64–71.
CrossRef |

Stephens SL (2005) Forest fire causes and extent on United States Forest Service lands. International Journal of Wildland Fire  14, 213–222.
CrossRef |

Stephens SL , Ruth LW (2005) Federal forest fire policy in the United States. Ecological Applications  15, 532–542.
CrossRef |

Stuiver M, Reimer PJ, Bard E, Beck JW, Burr GS, Hughen KA, Kromer B, McCormac FG, van der Plickt J , Spurk M (1998) INTCAL98 Radiocarbon age calibration 24000–0 cal BP. Radiocarbon  40, 1041–1083.


Swetnam TW (1993) Fire history and climate change in giant sequoia groves. Science  262, 885–889.
CrossRef | PubMed |

Swetnam TW, Baisan CH (1996) Historical fire regime patterns in the southwestern United States since AD 1700. In ‘Fire Effects in SouthWestern Forests: Proceedings of the Second La Mesa Fire Symposium’. (Ed. CD Allen) pp. 11–32. USDA Forest Service General Technical Report RM-GTR-286. (Fort Collins, CO)

Swetnam TW, Baisan CH (2003) Tree-ring reconstructions of fire and climate history in the Sierra Nevada and southwestern United States. In ‘Fire and climatic change in temperate ecosystems’. (Eds TT Veblen, WL Baker, G Montenegro, TW Swetnam) pp. 158–195. Ecological Studies 160. (Springer-Verlag: New York)

Swetnam TW , Betancourt JL (1998) Mesoscale disturbance and ecological response to decadal-scale climate variability in the American Southwest. Journal of Climate  11, 3128–3147.
CrossRef |

Thompson J (2002) Lime Creek Burn, 1879. San Juan Mountain Journal  3, 7–9.


Thompson RS, Whitlock C, Bartlein PJ, Harrison SP, Spaulding WG (1993) Climatic changes in the western United States since 18000 yr BP. In ‘global climates since the last glacial maximum’. (Eds HE Wright, Jr, JE Kutzbach, T Webb III, WF Ruddiman, FA Street-Perrott, PJ Bartlein) pp. 468–513. (University of Minnesota Press: Minneapolis, MN)

Toney JL , Anderson RS (2006) A post-glacial paleoecological record from the San Juan Mountains of Colorado: fire, climate and vegetation history. The Holocene  16(4), 505–517.
CrossRef |

Touchan R, Allen CD, Swetnam TW (1996) Fire history and climate patterns in ponderosa pine and mixed-conifer forests of the Jemez Mountains, northern New Mexico. In ‘Fire Effects in SouthWestern Forests: Proceedings of the Second La Mesa Fire Symposium’. (Ed. CD Allen) pp. 33–46. USDA Forest Service General Technical Report RM-GTR-286. (Fort Collins, CO)

USDA (2007) Plants profile. Pinus contorta Douglas ex Louden – lodgepole pine PICO. Available at http://plants.usda.gov/java/county?state_name=Colorado&statefips=08&symbol=PICO [Verified 11 January 2008]

Veblen TT, Hadley KS, Nel EM, Kitzberger T, Reid MS , Villalba R (1994) Disturbance regime and disturbance interactions in a Rocky Mountain subalpine forest. Journal of Ecology  82, 125–135.
CrossRef |

Vierling LA (1998) Palynological evidence for late-and post-glacial environmental change in central Colorado. Quaternary Research  49, 222–232.
CrossRef |

Weber WA, Wittmann RC (1996) ‘Colorado flora, Eastern Slope.’ (University Press of Colorado: Niwot, CO)

Weng C , Jackson ST (1999) Late-glacial and Holocene vegetation and climate history of the Kaibab Plateau, northern Arizona. Palaeogeography, Palaeoclimatology, Palaeoecology  153, 179–201.
CrossRef |

Whitlock C, Anderson RS (2003) Fire history reconstructions based on sediment records from lakes and wetlands. In ‘Fire and Climatic Change in Temperate Ecosystems’. (Eds TT Veblen, WL Baker, G Montenegro, TW Swetnam) pp. 3–31. Ecological Studies 160. (Springer-Verlag: New York)

Whitlock C, Shafer SL , Marlon J (2003) The role of climate and vegetation change in shaping past and future fire regimes in the north-western US and the implications for ecosystem management. Forest Ecology and Management  178, 5–21.
CrossRef |

Whitlock C, Skinner CN, Bartlein PJ, Minckley T , Mohr JA (2004) Comparison of charcoal and tree-ring records of recent fires in the eastern Klamath Mountains, California, USA. Canadian Journal of Forest Research  34, 2110–2121.
CrossRef |

Whitlock C, Bartlein P, Briles C, Brunelle A, Long CJ , Marlon J (2008) Long-term relations among fire, fuel, and climate in the north-western US based on lake sediment studies. International Journal of Wildland Fire  17, 72–83.
CrossRef |



Export Citation Cited By (35)