scholarly journals Forest thinning impacts on the water balance of Sierra Nevada mixed-conifer headwater basins

2017 ◽  
Vol 53 (7) ◽  
pp. 5364-5381 ◽  
Author(s):  
P. C. Saksa ◽  
M. H. Conklin ◽  
J. J. Battles ◽  
C. L. Tague ◽  
R. C. Bales
Keyword(s):  
Water Balance ◽  
Sierra Nevada ◽  
Mixed Conifer ◽  
Forest Thinning ◽  
Headwater Basins

Characterizing the light environment in Sierra Nevada mixed-conifer forests using a spatially explicit light model

2004 ◽  
Vol 34 (6) ◽  
pp. 1332-1342 ◽  
Author(s):  
Rolf Gersonde ◽  
John J Battles ◽  
Kevin L O'Hara
Keyword(s):  
Leaf Area ◽  
Sierra Nevada ◽  
Forest Type ◽  
Individual Species ◽  
Spatially Explicit ◽  
Conifer Forests ◽  
Prediction Equations ◽  
Mixed Conifer ◽  
Sapwood Area ◽  
Mixed Conifer Forests

The spatially explicit light model tRAYci was calibrated to conditions in multi-aged Sierra Nevada mixed-conifer forests. To reflect conditions that are important to growth and regeneration of this forest type, we sampled a variety of managed mature stands with multiple canopy layers and cohorts. Calibration of the light model included determining leaf area density for individual species with the use of leaf area – sapwood area prediction equations. Prediction equations differed between species and could be improved using site index. The light model predicted point measurements from hemispherical photographs well over a range of 27%–63% light. Simplifying the crown representation in the tRAYci model to average values for species and canopy strata resulted in little reduction in model performance and makes the model more useful to applications with lower sampling intensity. Vertical light profiles in managed mixed-conifer stands could be divided into homogeneous, sigmiodal, and continuous gradients, depending on stand structure and foliage distribution. Concentration of leaf area in the upper canopy concentrates light resources on dominant trees in continuous canopies. Irregular canopies of multiaged stands, however, provide more light resources to mid-size trees and could support growth of shade-intolerant species. Knowledge of the vertical distribution of light intensity in connection with stand structural information can guide regulation of irregular stand structures to meet forest management objectives.

scholarly journals Opportunities for winter prescribed burning in mixed conifer plantations of the Sierra Nevada

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Robert A. York ◽  
Jacob Levine ◽  
Kane Russell ◽  
Joseph Restaino
Keyword(s):  
Sierra Nevada ◽  
Pinus Ponderosa ◽  
Prescribed Burning ◽  
Winter Season ◽  
Basal Area ◽  
Weather Conditions ◽  
Shrub Cover ◽  
Mixed Conifer ◽  
Planted Forests ◽  
Conifer Plantations

Abstract Background Young, planted forests are particularly vulnerable to wildfire. High severity effects in planted forests translate to the loss of previous reforestation investments and the loss of future ecosystem service gains. We conducted prescribed burns in three ~35-year-old mixed conifer plantations that had previously been masticated and thinned during February in order to demonstrate the effectiveness of winter burning, which is not common in the Sierra Nevada, California. Results On average, 59% of fine fuels were consumed and the fires reduced shrub cover by 94%. The average percent of crown volume that was damaged was 25%, with no mortality observed in overstory trees 1 year following the fires. A plot level analysis of the factors of fire effects did not find strong predictors of fuel consumption. Shrub cover was reduced dramatically, regardless of the specific structure that existed in plots. We found a positive relationship between crown damage and the two variables of Pinus ponderosa relative basal area and shrub cover. But these were not particularly strong predictors. An analysis of the weather conditions that have occurred at this site over the past 20 years indicated that there have consistently been opportunities to conduct winter burns. On average, 12 days per winter were feasible for burning using our criteria. Windows of time are short, typically 1 or 2 days, and may occur at any time during the winter season. Conclusions This study demonstrates that winter burning can be an important piece of broader strategies to reduce wildfire severity in the Sierra Nevada. Preparing forest structures so that they can be more feasible to burn and also preparing burn programs so that they can be nimble enough to burn opportunistically during short windows are key strategies. Both small landowners and large agencies may be able to explore winter burning opportunities to reduce wildfire severity.

Empirically validated drought vulnerability mapping in the mixed conifer forests of the Sierra Nevada

2021 ◽  
Author(s):  
Adrian J. Das ◽  
Michèle R. Slaton ◽  
Jeffrey Mallory ◽  
Gregory P. Asner ◽  
Roberta E. Martin ◽  
...  
Keyword(s):  
Sierra Nevada ◽  
Vulnerability Mapping ◽  
Conifer Forests ◽  
Mixed Conifer ◽  
Drought Vulnerability ◽  
Mixed Conifer Forests
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