Defensible Space & Forest Health Recommendations
for Chinquapin on Lake Tahoe

Defensible Space Progress Reports
After the initial evaluation as follows there has been considerable defensible space work done as per the outlined Defensible Space & Forest Health Recommendations.

by Dan Scatena
Register Professional Forester #1909

PREFACE

This document provides recommendations based on defensible space programs developed for wildland/rural intermix by Local, State, Federal, Fire and Government agencies, Natural Resources Conservation Service, University of California Cooperative Extension, and State Law, Public Resource Code 4291. Defensible space refers to that area between homes and an oncoming wildfire where vegetation has been modified to reduce the wildfire threat. At the same time it allows the opportunity for firefighters to safely defend the structures. If vegetation is properly modified a wildfire can be slowed by reducing flames lengths, heat intensity, and rate of spread and keeps fire on the ground, which becomes easier to control. Low intensity ground fires are a lesser threat to homes, communities, forest canopy and habitats. When creating defensible space and improving forest health, homeowners must also consider insect, disease, and hazard tree management, especially in a recreational community where safety is the highest priority.

SITE LOCATION AND FUEL DESCRIPTION

Chinquapin on Lake Tahoe is a forest residential community on 97 acres located in Section 33, Township 16 North, Range 17 East, Mount Diablo Base Meridian, Placer County. Approximately four miles east of Tahoe City off of State HWY 28, on the north shore of Lake Tahoe at an elevation of 6229 feet. Aspect is southeast with flat to moderate sloping topography. Lake Tahoe to the south and east, Dollar Point subdivision to the west, and State HWY 28 to the north flank Chinquapin properties.

Vegetation is classified as Sierra mixed-conifer comprising of overstory trees of White Fir, Jeffrey Pine, Lodgepole Pine, Sugar Pine, and Incense Cedar. Understory vegetation is a mix of shrub species common to the Sierra’s and Lake Tahoe region. They consist of Huckleberry Oak, Snowbrush Ceanothus, Greenleaf Manzanita, Mountain Whitethron, Bitterbrush, Sagebrush, Currant, and Sierra Chinquapin. Also included in the understory vegetation regeneration of White Fir, Incense Cedar, and scattered Jeffrey Pine in disturbed open areas. Besides the above mentioned forest vegetation, there is accumulation of dead ground fuels. These fuels consist of needles, tree branches, tree-tops, down trees, and dead shrub species scattered throughout the common areas. All naturally occurring native plants and introduced species utilized in residential forest landscapes is potential wildfire fuel. The type, amount and arrangement of this vegetation (alive and dead) available for burning has a dramatic effect on fire behavior.

GENERAL RECOMMENDATIONS

In creating defensible space in forest residential landscapes the first step should be looking at a healthy stand of well spaced, existing conifers, where trees do not compete for the three basic needs of light, nutrients and moisture. Where possible trees should be spaced in small groups or spaced so as live canopy are not touching. An expert would evaluate trees to be thinned base on age, size, and vigor.

Trees that have been attacked by bark beetles and show signs of dying should be removed immediately to reduce spread to adjacent trees. Disease is another forest pest that should be evaluated especially root, heart, butt diseases which weaken trees that become safety hazards to life and property. Mistletoes in conifers are parasitic plants whose roots penetrate the woody branches and trunks of trees and extract nutrients. Mistletoe causes branches or trunk to swell and crack open, allowing heart rot fungi to enter thus weakening the tree and increasing to possibility of branches or the entire tree to fall. Trees with heavy mistletoe next to structures should be considered for removal. If trees exhibit mistletoe in the lower branches, 8-12 inches from the trunk, those branches could be pruned reducing or eliminating the parasite and improving tree vigor.

Defensible space and forest health planning on forest recreation and residential sites must also include hazard tree evaluation and control decisions. Understanding probability of failure, target impact, and damage potential is an important concept in evaluating hazard trees in forest landscapes. Examples of trees that may be considered in the hazard category are leaning, multi-top, adjacent to structures and driveways causing damage to property. It is important to evaluate these types of hazard trees by a qualified examiner with experience and knowledge for effective hazard rating and control.

Second step in creating defensible space and a healthy forest landscape is the removal of dead fuels for a minimum of 30 feet and as slopes increase treatment distance would increase up to 100 feet. This management practice can be accomplished by removing dead shrubs, accumulation of dead ground materials, and pruning dead branches for conifers. Maintain clean roofs and decks free of needles and other natural debris. Tree branches that overhang and come in contact with structures should be pruned. Limbs that are within 10 feet of a fireplace chimney are required to be removed. To maintain the health and vigor of trees, pruning of live branches should be done during the late fall/winter when they are dormant. Retaining the upper 2/3 of the live crown height is also important for maintaining tree vigor. It is never recommended to cut the tops of live conifers.

Step three deals with perhaps the most important area for developing defensible space and forest health and that is live vegetation between the home and the surrounding wildland, common areas, and adjacent property. What type of treatment and management done in these areas will determine fire behavior and if the home is defendable by fire crews. Fuels in these high priority areas of both mixed conifers and shrub species that under the proper conditions burn with great intensity and at a rapid rate of spread. Treatment of shrubs should be by thinning, using a pruning technique creating openings or islands free of vegetation. The greater the density and height of shrubs the larger of openings, creating a mosaic landscape effect.

Conifers in these areas should be treated in the same prescription as mentioned in step one. Remembering that pruning is very important of the lower branches to reduce ladder effect of fuels and preventing a ground fire becoming a crown fire.

It is equally important to remember that when creating defensible space the property owner must be cognizant of water quality concerns. Treatments done inappropriately, implementing defensible space concepts could encourage accelerated soil erosion. Furthermore, the removal of all vegetation from the treatment area is aesthetically unacceptable. Thus creating islands in dense brush fields in a mosaic fashion is important. Most shrub species are prolific sprouts so live root systems are still anchoring the soil. When removing forest fuels, do so in a manner, which will result in a minimum of soil disturbance.

Step four address fire resistant landscaping and developing a continuing maintenance program. When landscaping with fire resistant plants they should be selected for their ability to thrive under local soil and climate conditions. Most State Foresters, Cooperative Extension, or a local nursery can suggest those suitable for the area and blend in with the native plants.

Vegetation modification and management programs provide short-term salutation in creating defensible space and healthy forest landscapes. Shrubs and conifers will regenerate new plants, and existing plants increase in size from year to year creating future management decisions. Each year plants naturally produce dead material both on the ground and within the plants, which accumulates and requires a long-term maintenance program. Conifers adjacent to structures may create concerns that may have to be evaluated from year to year by a qualified Forester.

The establishment of a grounds committee providing recommendations on annual work requirements and priorities to meet defensible space and healthy forest objectives would be an asset to property owners.

RECOMMENDATIONS AND PRIORITIES FOR CHINQUAPIN ON LAKE TAHOE

On May 7, 2003, a field inspection was conducted of Chinquapin on Lake Tahoe, by Dan Jones, WMC, and Dan Scatena, Forester, to evaluate the properties in order to make recommendations and set priorities for improving defensible space while creating a healthy forest habitat, and provide safety to the residents of Chinquapin. During this review the area of concern focused on vegetation issues surrounding the individuals units, recreational facilities, roadways and parking areas. The common area extending out to Dollar Point and up to Dollar subdivision has had past forest management activity and will be reevaluated at a future date.

Listed below are specific recommendations by priority which where noted during the May 7th field inspection:

1. Vegetation modification in the common area directly behind units 17-20,72-92,and 175-190. Units 17-20 and 72-92 being the biggest concern due to old dense stands of contiguous shrubs with scattered overstory conifers which would fuel extreme fire behavior and present an unsafe environment for fire crews in defending those units during a wildfire. Treatment of the shrubs fields should be thinning, creating openings, leaving scattered islands or well spaced individual plants in a mosaic natural landscape appearance. Keep in mind that height and density of vegetation influences size of openings to create. The treatment area should extend a minimum of 30 feet on flat to gentle topography, up to 100 feet on steeper slopes. Units 72-92 it is recommended that the fuel modification extend to the entrance drive. Dead fuels have accumulated both in standing vegetation and on the ground, which should be removed or chipped. Chipping in place is the preferred alternative for disposing unwanted forest material. Chips provide an excellent ground cover in preventing soil erosion. Conifers in this defensible space zone require management practices that will reduce the possibility of a crown fire and increase forest health. Removal of dead and dying bark beetle infested trees will prevent additional mortality and at the same time reduce hazardous forest fuels. Conifers that exhibit lower branches close to the ground or extend into the shrubs should be pruned and shrubs removed from under the tree which breaks-up the ladder effect of fuels. Also, consider where necessary thinning slow growing, stressed, White Fir in the defensible space zone which will reduce forest fuels, increase vigor of residual trees, and provide a more pleasing aesthetic forest landscape.
   
   
2. Good tree management for defensible space, safety, and a healthy forest adjacent to all of Chinquapin’s residential and recreational facilities should be a continued objective. Trees in these areas should be evaluated periodically by a professional forester for insect/diseased and hazard trees evaluation and recommendations. Lack of action to remove these trees could result in additional tree mortality and safety concerns to life and property. Overhanging tree branches in contact with roofs or buildings should be pruned; pine needle and other forest materials on roofs and decks removed, and remove any portion of a tree that extends within 10 feet of the fireplace outlet. There are several areas adjacent to some of the units that have groups of small diameter (6 inches or less) White Fir thickets. Thickets should be thinned to allow for the proper spacing, reduce ladder fuels, and improve residual tree vigor.
   
   
3. Treatment of the common areas beyond the 30-100 foot defensible space zone above the entrance drive to HWY 28 should incorporate best management practices for providing healthy forest, protecting forest habitat, soil, and water quality while maintaining an aesthetically acceptable natural landscapes. Continuation of an active maintenance program of removing dead and insect/diseased trees, accumulation of dead fuels, and some minor thinning of dense shrub fields, (especially above the entrance drive) creating small openings in a mosaic pattern blending into the natural landscape.
   
   
4. Dollar Creek is considered a class I watercourse originating east of Mt. Watson and flowing through Chinquapin and into Lake Tahoe. Fish and other aquatic life are present and therefore, retaining overstory trees and understory riparian vegetation for shade and sediment filter strip protection is virtually important. It’s recommended that no activity occur within 75 feet on flat topography to 150 feet on steeper slopes on both sides of the channel. Only hazardous trees that threaten life and property be considered for removal within the stream environment zone, any other activity should not take place without notification of Department of Fish & Game, Lahanton Water Quality, and TRPA.

FIRE HAZARD SEVERITY MAP*

The California Department of Forestry and Fire Protection (CDF) evaluates wildland in its direct fire protection responsibility areas, know as State Responsibility Areas (SRA), and rates fire hazard severity for those areas.

The fire hazard severity map for Chinquapin on Lake Tahoe is included in an area in which the local fire protection agency in this case, North Tahoe Fire protection District, provides direct fire protection. Therefore, CDF has not rated the area. However, the entire surrounding area is rated moderate, one could assume that area in white and gray would be rated moderate as well.

*Map is very large and not appropriate for display on web site but is available for viewing at the WMC Office.

REFERENCES

The Defensible Space and Healthy Forest Handbook (Meadow Vista Community Plan) 1997

Tree City USA Bulletin 41 Reduce Wildfire Risk

California Department of Forestry and Fire Protection, Nevada-Yuba-Placer, Ranger Unit, Fire Captain, Sean Griffs, Truckee Area Forester, Jeff Dowling.

Saving Pines from Dwarf Mistletoe, U.S.F.S. Research paper, RM-35

Protecting trees when Building on Forested Lands, University of California, Leaflet #21348

Accident Hazard Evaluation and Control Decisions on Forested Recreation Sites, U.S.F.S. Research Paper PSW 68/1971, Lee A. Paine

Hazard Rating Guide for Coniferous trees in the Lake Tahoe Region, M.D. Hansen, T.R.P.A.

California Public Resources Code 4291

For inquiries please contact the appropriate Board Member or Committee Chairperson.

"Keeping Chinquapin Homeowners Informed"

URL: http://chinquapinhoa.com/defensible_space_report.htm
Last modified: 01/17/09