Coarse woody debris and canopy cover in an old-growth Jeffrey pine-mixed conifer forest from the Sierra San Pedro Martir, Mexico

2007 ◽  
Vol 240 (1-3) ◽  
pp. 87-95 ◽  
Author(s):  
Scott L. Stephens ◽  
Danny L. Fry ◽  
Ernesto Franco-Vizcaíno ◽  
Brandon M. Collins ◽  
Jason M. Moghaddas
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Canopy Cover ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
Old Growth ◽  
Jeffrey Pine ◽  
San Pedro ◽  
Mixed Conifer Forest ◽  
Sierra San Pedro Martir

Phytolith evidence for the absence of a prehistoric grass understory in a Jeffrey pine – mixed conifer forest in the Sierra San Pedro Mártir, Mexico

2007 ◽  
Vol 37 (2) ◽  
pp. 306-317 ◽  
Author(s):  
Rand R. Evett ◽  
Ernesto Franco-Vizcaino ◽  
Scott L. Stephens
Keyword(s):  
Fire Regime ◽  
Grass Cover ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
High Concentration ◽  
Fire Scar ◽  
Jeffrey Pine ◽  
San Pedro ◽  
Mixed Conifer Forest ◽  
Sierra San Pedro Martir

Phytolith analysis was applied to several sites in a Jeffrey pine ( Pinus jeffreyi Grev. & Balf.) – mixed conifer forest in the Sierra San Pedro Mártir, Baja California, Mexico, to explore the hypothesis that the introduction of livestock in the late 18th century led to overgrazing of a prehistoric grass understory, resulting in changes to the prehistoric fire regime observed in the tree-ring fire-scar record. Stable soils in regions with extensive prehistoric grass cover retain a high concentration of total phytoliths and high percentage of grass phytoliths, regardless of historic vegetation changes. Phytoliths extracted from soil samples collected from several sites in the Sierra San Pedro Mártir revealed total phytolith concentrations in forest soils were generally <0.5% by mass, with most <0.1%, whereas grass phytoliths were generally <10% of the total, values consistent with the interpretation of a forest with sparse grass cover in the understory. Phytolith evidence suggests that there was minimal grass available for grazing in prehistoric Sierra San Pedro Mártir forests; overgrazing a grass understory was probably not a major driver of changes in the prehistoric fire regime.

scholarly journals Coarse Woody Debris Following Silviculture Treatments in Southwest Mixed-Conifer Forest

Forests ◽  
2018 ◽  
Vol 9 (6) ◽  
pp. 347
Author(s):  
Pradip Saud ◽  
Douglas Cram ◽  
Samuel Smallidge ◽  
Terrell Baker
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
Mixed Conifer Forest

Comparing modern and past fire regimes to assess changes in prehistoric lightning and anthropogenic ignitions in a Jeffrey pine – mixed conifer forest in the Sierra San Pedro Mártir, Mexico

2007 ◽  
Vol 37 (2) ◽  
pp. 318-330 ◽  
Author(s):  
Rand R. Evett ◽  
Ernesto Franco-Vizcaino ◽  
Scott L. Stephens
Keyword(s):  
Fire Regime ◽  
Climatic Factors ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
The Past ◽  
Jeffrey Pine ◽  
San Pedro ◽  
Sierra San Pedro Martir

Fire histories of Jeffrey pine ( Pinus jeffreyi Grev. & Balf.) – mixed conifer forests in the Sierra San Pedro Mártir, Baja California, Mexico, recently described through analysis of 300 years of tree-ring fire-scars, indicate there have been four distinct fire-regime periods based on fire frequency and size. We used modern lightning and fire data to assess whether the current lightning regime could have supported the prehistoric fire regime. Although there are several sources of uncertainty, the present lightning regime, concentrated in the summer with little spring activity, may be insufficient to support the high number and spring seasonality of fires recorded during some periods in the past. Changes in the ignition regime recorded during the past 300 years could have been due to anthropogenic and (or) climatic factors; available evidence suggests periods of frequent fire were dominated by anthropogenic ignitions.

Stand-level spatial dependence in an old-growth Jeffrey pine – mixed conifer forest, Sierra San Pedro Mártir, Mexico

2010 ◽  
Vol 40 (9) ◽  
pp. 1803-1814 ◽  
Author(s):  
Danny L. Fry ◽  
Scott L. Stephens
Keyword(s):  
Spatial Pattern ◽  
Forest Structure ◽  
Forest Ecosystems ◽  
Conifer Forest ◽  
Spatial Correlations ◽  
Mixed Conifer ◽  
Old Growth ◽  
Jeffrey Pine ◽  
Old Growth Forest ◽  
Mixed Conifer Forest

Descriptions of spatial patterns are important components of forest ecosystems, providing insights into functions and processes, yet basic spatial relationships between forest structures and fuels remain largely unexplored. We used standardized omnidirectional semivariance modeling to examine the spatial pattern of fuels and forest structure measured in a systematic nested plot grid covering 144 ha. Forest structure variables were spatially dependent at scales ranging from 62 to 572 m. Cross-variograms of fuels and forest structure showed both positive and negative correlations, ranging from 0.04 to 0.67. Notably, fine fuels were correlated positively and negatively with forest structure variables of white fir ( Abies concolor (Gord. & Glend.) Lindl. ex Hildebr.) and Jeffrey pine ( Pinus jeffreyi Balf.), respectively. Old-growth Jeffrey pine – mixed conifer forest within the study area exhibited both identifiable spatial correlations and high stand-level spatial heterogeneity, as demonstrated by the influence of outliers on the underlying spatial pattern. The spatial dependency of fuels with species-specific variables suggests that less common species may have a large influence in the characterization of forest attributes and that fuel classifications may be improved by accounting for the spatial distributions of overstory species. Spatial correlations have many applications to forest management, including the classification and mapping of forest structure, establishing guidelines for fuel treatments, and restoration of old-growth forest ecosystems.

scholarly journals Black Carbon on Coarse Woody Debris in Once- and Twice-Burned Mixed-Conifer Forest

Fire Ecology ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 143-147 ◽  
Author(s):  
Aspen Ward ◽  
C. Alina Cansler ◽  
Andrew J. Larson
Keyword(s):  
Black Carbon ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
Mixed Conifer Forest
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