Total Old Growth
The total old growth indicator characterizes the proportion of the Tahoe Region dominated by stands of old growth conifers. Old growth forests are valued because they add to Tahoe’s ecological integrity by providing a greater diversity of life forms, including a variety of unique lichen, fungi, insects, vegetation, and wildlife. Old growth forests tend to be more structurally and biologically complex and resilient to natural disturbances (such as wildfire) than younger forests, due to tree spacing and fire resistance of bark on mature trees, especially pines. Soil conditions, aspect, hill slope position, drought frequency, direct sunlight, fire suppression, climate patterns, time, and natural disturbance influence the extent and distribution of large-diameter trees. TRPA and Environmental Improvement Program (EIP) partners have adopted several policies, ordinances and implementing programs designed to promote the conservation and protection of old growth forests. EIP partners have implemented numerous forest restoration and enhancement projects, mostly to thin overstocked conifer stands to reduce the potential for catastrophic wildfire and restore conifer tree densities consistent with historical conditions. At average growth or mortality rates, significant change is unlikely to be observed in this indicator over a four-year evaluation period.
Status
Estimated acres of conifer stands dominated by trees greater than 25-inches dbh (“old growth” forest stands) in three elevation zones in the Tahoe Region. Some forest types remain unclassified resulting in the N/A column.
Evaluation Map
Late Seral Forested Areas
2019 Evaluation
- Status
- Considerably Worse Than Target
- Trend
- Little or No Change
- Confidence
- Low
Applicable Standard
VP12: Attain and maintain a minimum percentage of 55 percent by area of forested lands within the Tahoe Region in a late seral or old growth condition, and distributed across elevation zones. Standards VP13, VP14, and VP15 must be attained to achieve this threshold.
Key Points
- Currently 1.6 percent of the Tahoe Region's forest is old growth.
- The majority of the Region's trees were logged in the Comstock era, so that today's forest is largely mid-stage second growth. In absence of catastrophic wildfire, it is estimated that the Region's second growth forest will mature into old growth in about 100 years.
- Catastrophic wildfire is the greatest threat to the Region's forest.