Dead or severely cankered branches should be removed. Prune only when
bark surfaces are dry or during the dormant season.
Newly transplanted or mature, high value trees may need protection from
leafspot diseases such as anthracnose and from insect defoliators and
various sucking insects such as aphids or scales. It should be noted
that leafspot diseases are not severe every year. Trees need protection
during spring seasons that have frequent rainfall at budbreak and during
leaf expansion. Refer to the enclosed USDA Forest Service brochure
entitled, How To Identify and Control Dogwood Anthracnose, for more
information. Although the above mentioned publication deals specifically
with dogwood anthracnose, the cultural control recommendations are
applicable for leafspot diseases of trees and shrubs in general. A
fungicide not mentioned, thiophanate methyl, is labeled for control of
anthracnose on shade trees and woody ornamentals. Several tradenames of
fungicides that contain thiophante methyl include Cleary 3336, Topsin M,
Domain, Fungo and Zyban.1 Fungicides should be used only to supplement a
cultural control program. Read fungicide labels carefully to determine
registered uses and application rates.
Forest Stands
Any harvest or salvage activities should create a minimum of damage to
remaining or regenerating trees or disturbance to the site itself. Soil
compaction, rutting, bark removal, and branch breakage can all act as
additional stress on other trees in the stand.
Salvage activities such as ”sanitation cuts” can be beneficial by
removing breeding material of stem boring insects. (See Management
Implications section for additional salvage considerations).
Insecticide use is rarely practical or ecologically sound in forested
situations.
Hazard Evaluation of Flood Damaged Trees
As noted above, flooding results in some trees being stressed,
physically damaged, and/or insect and disease infested. These trees
possess defects that decrease their structural integrity, making them
more prone to windthrow and structural failure. Defective trees located
in high use areas such as yards, parks, or other recreational areas are
hazardous and pose safety risks to people and property.
Mature, well-established trees are more tolerant of flooding than over
mature trees or seedlings of the same species. If flooding is recurrent
or uninterrupted and keeps soils saturated, serious damage to trees may
occur.
Flooding during the growing season typically is more harmful to trees
than flooding during dormant periods. Flood-stressed trees exhibit a
wide range of symptoms including yellowing leaves, defoliation, reduced
leaf size and shoot growth, crown dieback and sprouts along the stem or
trunk. Symptoms may progress into tree decline and death, reoccur for
several years and then eventually disappear, or subside by as early as
next year indicating rapid tree recovery.
Flooding reduces the supply of oxygen to the soil and roots and usually
results in growth inhibition and injury to flooded trees. Deposits of
silt or sand as shallow as three inches can be injurious, especially to
newly planted trees. Tree roots also must contend with high
concentrations of toxic compounds that accumulate in waterlogged soils.
Strong currents and soil particles suspended in flood waters can erode
soil from around the base of trees exposing tree roots. Exposed roots
are vulnerable to drying and mechanical injury and their occurrences may
make trees more vulnerable to windthrow. Flood-stressed trees are prime
candidates for attack by secondary organisms. Several opportunistic
disease-causing fungi and insects invade trees that are weakened or
stressed. Minimizing additional stress or injuries should be a priority
on high value trees for one to three years after flooding to reduce the
chance of attack by insects.
?The best approach to managing flood-stressed trees is
to enhance their vigor by following proper tree-maintenance practices
and eliminating additional stresses. Dead or severely cankered branches
should be removed as soon as possible. Aerating the soil, mulching and
watering during extended dry periods are recommended tree-care
practices that can help enhance vigor, but they are not rescue
treatments for severely injured trees. Trees developing substantial
dieback and decline symptoms or those possessing defects that prone to
windthrow and structural failure should be removed from the landscape
immediately.
More of the same topic in the following links:
flood, floods and water damage
Graeme Stephens has been running the largest owned carpet cleaning companyin new Zealand for 24 years. IICRC qualified “master restoration technician”