Within the past forty years land managers, scientists, and conservationists have greatly altered their views on forest health management. Until fairly recently, local management objectives on much of our local forestland included suppressing wildfires and protecting trees from being cut.
As a result many of these forest stands became over stocked. A healthy forest in the San Bernardino Mountains would typically have between 90 and 150 trees per acre while much of the forest has 600 to 800 trees per acre. With all of this excess fuel present the fires are difficult to control, often burning so hot that the larger trees are killed, soil is scorched, and wildlife habitats are destroyed.
When trees exist in close proximity, they compete for the same limited amount of water, nutrition and sunlight. During the cyclical drought conditions found in the Big Bear Valley trees go into a stressed condition. When trees are stressed their ability to survive a Bark Beatle attack is reduced.
A great resource for property owners comes from the University of Arizona titled, “Guidelines for Thinning Ponderosa Pine for Improved Forest Health and Fire Prevention." This is an extensive hands-on publication to help property owners determine proper tree spacing, age, class, and diversity of size for creating a healthy forest on their own property. In using this guide, Big Bear Valley property owners may use the recommended elevation of 6,500 feet and 24 inches as the average precipitation.
The Big Bear Lake Fire Department offers over-the-phone guidance and/or property site visits to assist Big Bear Lake property owners in completing an evaluation of their property. The Big Bear Lake Fire Department can be reached at 909/866-4668.
NOTE: Currently within the City of Big Bear Lake, small trees less than 6 inches in diameter within 8 feet of another larger tree are the only trees required by local ordinance to be removed. Trees larger then 6 inches require a permit.
To assist property owners with tree thinning FOREST CARE PROGRAM will reimburse property owners up to 75% of the cost of thinning trees and removing overgrown vegetation. To see if your property qualifies for the FOREST CARE PROGRAM click on this website: http://www.sbnfa.org/forestcare.php
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This photo shows just how dense the tree population was prior to thinning. Many of the trees which existed were less than 20 feet from larger older trees. When trees exist in close proximity, they compete for the same limited amount of water, nutrition and sunlight. During the cyclical drought conditions found in the Big Bear Valley trees go into a stressed condition. When trees are stressed their ability to survive a Bark Beatle attack is reduced.
During a Fire Scenario trees in close proximity to each other allows the fire to jump from tree to tree. Thinning trees to assure adequate separation between tree crowns aids in reducing the intensity and potential spread of a wildfire.
Smaller trees act as ground fuel which creates a laddering effect for the fire to progress from the ground up and through lower tree branches and ultimately igniting tree crowns. Removing these smaller trees and the lower tree branches all helps to reduce the ability of fire to travel up and through the crowns of trees. Once the crown of a tree is on fire it is more difficult to extinguish and easier for fire to jump from crown to crown.
Currently, the City of Big Bear Lake requires the elimination of smaller trees less than 6 inches in diameter and within 8 feet proximity of a another tree. Although 20 to 30 feet separation is ideal, starting with the removal of smaller trees within 8 feet of larger, more dominant tree is a great start in the right direction. |
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| This Photograph was taken after nearly 1000 smaller trees were removed at the Bear Valley Unified School District. The remaining trees in this picture generally have a minimum spacing of 20 to 30 feet. All tree branches less than 6 feet from the ground were removed. This tree stand is predominately Jeffrey Pine Trees. The dominant native tree found in the Big Bear Valley. |
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USFS
Big
Bear
Lake
Shaded
Fuel
Break
Project
along
the
edge
of the
San
Bernardino
National
Forest
and
the
City
of Big
Bear
Lake. This
area
was
heavily
forested
and
difficult
to walk
through.
By
thinning
out
the
overgrown
forest
the
fire
threat
to the
community
immediately
adjacent
to the
forest
is reduced.
Thinning
the
forest
also
creates
a more
open,
park
type
setting
and
enhances
the
survivability
of the
remaining
trees
by reducing
the
competition
among
trees
for
the
same
water
and
nutrition
or if
a ground
fire
were
to spread
through
this
area. Finally,
it adds
to the
biodiversity
of this
area. Notice
the
low
level
of soil
disturbance
from
the
mechanical
thinning. |
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