Historical and current landscape‐scale ponderosa pine and mixed conifer forest structure in the Southern Sierra Nevada

Many managers today are tasked with restoring forests to mitigate the potential for uncharacteristically severe fire. One challenge to this mandate is the lack of large-scale reference information on forest structure prior to impacts from Euro-American settlement. We used a robust 1911 historical dataset that covers a large geographic extent (>10,000 ha) and has unbiased sampling locations to compare past and current forest conditions for ponderosa pine and mixed conifer forests in the southern Sierra Nevada. The 1911 dataset contained records from 18,052 trees in 378 sampled transects, totaling just over 300 ha in transect area. Forest structure was highly variable in 1911 and shrubs were found in 54% of transects. Total tree basal area ranged from 1 to 60 m2 ha−1 and tree density from 2 to 170 ha−1 (based on trees >30 cm dbh). K-means cluster analysis divided transects into four groups: mixed conifer-high basal area (MC High BA), mixed conifer-average basal area (MC Ave BA), mixed conifer-average basal ...

[1]  S. B. Show,et al.  Cover Type and Fire Control in the National Forests of Northern California , 2017 .

[2]  S. Stephens,et al.  Novel characterization of landscape-level variability in historical vegetation structure. , 2015, Ecological applications : a publication of the Ecological Society of America.

[3]  Malcolm P. North,et al.  Water balance and topography predict fire and forest structure patterns , 2015 .

[4]  J. Franklin,et al.  Historical conditions in mixed-conifer forests on the eastern slopes of the northern Oregon Cascade Range, USA , 2014 .

[5]  S. Dobrowski,et al.  Changing forest structure across the landscape of the Sierra Nevada, CA, USA, since the 1930s , 2014 .

[6]  W. Baker.  Historical forest structure and fire in Sierran mixed-conifer forests reconstructed from General Land Office survey data , 2014 .

[7]  J. Varner,et al.  A Mixed-Effects Heterogeneous Negative Binomial Model for Postfire Conifer Regeneration in Northeastern California, USA , 2014 .

[8]  S. Stephens,et al.  Contrasting Spatial Patterns in Active-Fire and Fire-Suppressed Mediterranean Climate Old-Growth Mixed Conifer Forests , 2014, PloS one.

[9]  E. Knapp,et al.  Long-term overstory and understory change following logging and fire exclusion in a Sierra Nevada mixed-conifer forest , 2013 .

[10]  Joshua H. Viers,et al.  Modern departures in fire severity and area vary by forest type, Sierra Nevada and southern Cascades, California, USA , 2013 .

[11]  T. Swetnam,et al.  Managing Forests and Fire in Changing Climates , 2013, Science.

[12]  J. Franklin,et al.  Historical structure and composition of ponderosa pine and mixed-conifer forests in south-central Oregon , 2013 .

[13]  E. Knapp,et al.  Quantifying spatial patterns of tree groups and gaps in mixed-conifer forests: Reference conditions and long-term changes following fire suppression and logging , 2013 .

[14]  B. Collins,et al.  Early forest dynamics in stand-replacing fire patches in the northern Sierra Nevada, California, USA , 2013, Landscape Ecology.

[15]  P. Hessburg,et al.  Restoring forest resilience: From reference spatial patterns to silvicultural prescriptions and monitoring , 2013 .

[16]  M. North,et al.  Topographic Variation in Structure of Mixed-Conifer Forests Under an Active-Fire Regime , 2012, Ecosystems.

[17]  Jan W. van Wagtendonk,et al.  Factors Associated with the Severity of Intersecting Fires in Yosemite National Park, California, USA , 2012 .

[18]  W. Baker.  Implications of spatially extensive historical data from surveys for restoring dry forests of Oregon's eastern Cascades , 2012 .

[19]  A. Larson,et al.  Tree spatial patterns in fire-frequent forests of western North America, including mechanisms of pattern formation and implications for designing fuel reduction and restoration treatments , 2012 .

[20]  P. Fulé,et al.  Woody debris and tree regeneration dynamics following severe wildfires in Arizona ponderosa pine forests , 2012 .

[21]  Tongli Wang,et al.  ClimateWNA—High-Resolution Spatial Climate Data for Western North America , 2012 .

[22]  H. Safford,et al.  A Summary of Fire Frequency Estimates for California Vegetation before Euro-American Settlement , 2011 .

[23]  S. Stephens,et al.  Impacts of fire exclusion and recent managed fire on forest structure in old growth Sierra Nevada mixed-conifer forests , 2011 .

[24]  Malcolm P. North,et al.  Carbon recovery rates following different wildfire risk mitigation treatments , 2010 .

[25]  Scott L. Stephens,et al.  Operational approaches to managing forests of the future in Mediterranean regions within a context of changing climates , 2010 .

[26]  S. Stephens,et al.  Stand-replacing patches within a ‘mixed severity’ fire regime: quantitative characterization using recent fires in a long-established natural fire area , 2010, Landscape Ecology.

[27]  A. Taylor,et al.  Fire regimes, forest change, and self-organization in an old-growth mixed-conifer forest, Yosemite National Park, USA. , 2010, Ecological applications : a publication of the Ecological Society of America.

[28]  T. Swetnam,et al.  Multi-Millennial Fire History of the Giant Forest, Sequoia National Park, California, USA , 2009 .

[29]  Peter Z. Fulé,et al.  Changes in forest structure of a mixed conifer forest, southwestern Colorado, USA. , 2009 .

[30]  Jerry F. Franklin,et al.  Twentieth-century decline of large-diameter trees in Yosemite National Park, California, USA , 2009 .

[31]  Jason J. Moghaddas,et al.  Fire treatment effects on vegetation structure, fuels, and potential fire severity in western U.S. forests. , 2009, Ecological applications : a publication of the Ecological Society of America.

[32]  Peter Z. Fulé,et al.  Does It Make Sense to Restore Wildland Fire in Changing Climate? , 2008 .

[33]  S. Stephens,et al.  Wildfire and Spatial Patterns in Forests in Northwestern Mexico: The United States Wishes It Had Similar Fire Problems , 2008 .

[34]  Achim Zeileis,et al.  Conditional variable importance for random forests , 2008, BMC Bioinformatics.

[35]  R. Minnich,et al.  Densification, stand-replacement wildfire, and extirpation of mixed conifer forest in Cuyamaca Rancho State Park, southern California , 2008 .

[36]  S. Stephens,et al.  Managing natural wildfires in Sierra Nevada wilderness areas , 2007 .

[37]  Scott L. Stephens,et al.  Prehistoric fire area and emissions from California's forests, woodlands, shrublands, and grasslands , 2007 .

[38]  Jim InnesJ. Innes,et al.  Comparison of thinning and prescribed fire restoration treatments to Sierran mixed-conifer historic conditions , 2007 .

[39]  Harold S. J. Zald,et al.  Influence of soil thickness on stand characteristics in a Sierra Nevada mixed-conifer forest , 2007, Plant and Soil.

[40]  S. Stephens,et al.  Coarse woody debris and canopy cover in an old-growth Jeffrey pine-mixed conifer forest from the Sierra San Pedro Martir, Mexico , 2007 .

[41]  K. Hornik,et al.  Unbiased Recursive Partitioning: A Conditional Inference Framework , 2006 .

[42]  Carl N. Skinner,et al.  Basic principles of forest fuel reduction treatments , 2005 .

[43]  S. Stephens,et al.  Forest structure and mortality in an old-growth Jeffrey pine-mixed conifer forest in north-western Mexico , 2005 .

[44]  M. M. Moore,et al.  Comparison of Historical and Contemporary Forest Structure and Composition on Permanent Plots in Southwestern Ponderosa Pine Forests , 2004 .

[45]  Jerry F. Franklin,et al.  Spatial Aspects of Structural Complexity in Old-Growth Forests , 2004, Journal of Forestry.

[46]  C. Allen,et al.  ECOLOGICAL RESTORATION OF SOUTHWESTERN PONDEROSA PINE ECOSYSTEMS: A BROAD PERSPECTIVE , 2002 .

[47]  Malcolm P. North,et al.  Vegetation and ecological characteristics of mixed-conifer and red fir forests at the Teakettle Experimental Forest , 2002 .

[48]  B. McCune,et al.  Analysis of Ecological Communities , 2002 .

[49]  Andrew M. Barton.  Intense wildfire in southeastern Arizona: transformation of a Madrean oak-pine forest to oak woodland , 2002 .

[50]  M. M. Moore,et al.  Natural variability in forests of the Grand Canyon, USA , 2002 .

[51]  J. Battles,et al.  Forest Composition, Structure, and Change in an Old-Growth Mixed Conifer Forest in the Northern Sierra Nevada , 1998 .

[52]  N. Stephenson,et al.  Actual evapotranspiration and deficit: biologically meaningful correlates of vegetation distribution across spatial scales , 1998 .

[53]  Peter Z. Fulé,et al.  Restoring Ecosystem Health in Ponderosa Pine Forests of the Southwest , 1997, Journal of Forestry.

[54]  W. Covington,et al.  Effect of Periodic Burning on Soil Nitrogen Concentrations in Ponderosa Pine , 1986 .

[55]  Alan S. White.  Presettlement regeneration patterns in a southwestern Ponderosa pine stand , 1985 .

[56]  W. H. Hutchinson.  Pino Grande: Logging Railroads of the Michigan-California Lumber Co. By R.S. Polkinghorn. The Whistles Blow No More: Railroad Logging in the Sierra Nevada 1874-1942. By Hank Johnston , 1985 .

[57]  A. J. Parker,et al.  THE TOPOGRAPHIC RELATIVE MOISTURE INDEX: AN APPROACH TO SOIL-MOISTURE ASSESSMENT IN MOUNTAIN TERRAIN , 1982 .

[58]  J. A. Hartigan,et al.  A k-means clustering algorithm , 1979 .

[59]  Dan Taylor,et al.  FIRE HISTORY OF A SEQUOIA-MIXED CONIFER FOREST' , 1979 .

[60]  R. Ornduff,et al.  Terrestrial Vegetation of California. , 1977 .

[61]  J. F. Howell,et al.  Pairwise Multiple Comparison Procedures with Unequal N’s and/or Variances: A Monte Carlo Study , 1976 .

[62]  Brandon M. Collins,et al.  Fire and Fuels , 1975 .

[63]  B. L. Welch.  ON THE COMPARISON OF SEVERAL MEAN VALUES: AN ALTERNATIVE APPROACH , 1951 .

[64]  Andrew J. Sánchez Meador,et al.  Restoring composition and structure in Southwestern frequent-fire forests: A science-based framework for improving ecosystem resiliency , 2013 .

[65]  J. Varner,et al.  Post-fire regeneration across a fire severity gradient in the southern Cascades , 2013 .

[66]  J. Wagtendonk.  Invited Features Fires in wilderness in the national parks , 2012 .

[67]  G. Tutz,et al.  An introduction to recursive partitioning: rationale, application, and characteristics of classification and regression trees, bagging, and random forests. , 2009, Psychological methods.

[68]  G. E. Dixon.  Essential FVS: A User's Guide to the Forest Vegetation Simulator , 2007 .

[69]  A. Taylor,et al.  Fire and persistence of montane chaparral in mixed conifer forest landscapes in the northern Sierra Nevada, Lake Tahoe Basin, California, USA1 , 2005 .

[70]  William A. Bechtold,et al.  The enhanced forest inventory and analysis program - national sampling design and estimation procedures , 2005 .

[71]  T. Swetnam,et al.  Tree-Ring Reconstructions of Fire and Climate History in the Sierra Nevada and Southwestern United States , 2003 .

[72]  Paula J. Fornwalt,et al.  Using the Forest Vegetation Simulator to reconstruct historical stand conditions in the Colorado Front Range , 2002 .

[73]  Michael J. Oimoen,et al.  The National Elevation Dataset , 2002 .

[74]  J. Kauffman,et al.  Factors influencing the scarification and germination of three montane Sierra Nevada shrubs , 1991 .

[75]  David J. Parsons,et al.  Impact of fire suppression on a mixed-conifer forest , 1979 .