Forest Management

Diseases and Pests

that effect a good harvest stand

What is a Disease?

Definition disorder that is

caused by something specific with consistant symptoms.

Types of Diseases…Abiotic

nonliving agent causeBiotic

living agent causes• fungus, bacteria,

parasite, virus, nematodes

Fungus

Most destructive in forests Threadlike plants that do not make their

own food.Parasitic- when taking food from a living

treeSaprophytic- when taking food from dead

trees to aid in humus production.

Biotic Diseases of Trees

Wood Rots

Cause: Fungus decay in trees Break down cellulose

and lignin in cell walls Very harmful because

they are hard to detect from the outside of a living tree.

2 TypesWhite Rot- break

down of cellulose and lignin in the cell walls.

Brown Rot- only break down cellulose

70% of all timber lost

Biotic Disease continued...

Symptoms Conk- specialized

growth on outside containing fungal spores spread when opened. • Look like

mushrooms growing on the sides of the trunk

Prevention Prevent scaring of

trees Rotate harvest age Harvest more

frequently in mixed age forests

Using these methods doesn’t give fungus the chance to grow.

CankerCause

fungus entering through wounds in the bark

cause lesions that produce callus tissue and damage the woody tissue of the tree, making it less valuable

Symptoms weak trees decay for no apparent

reason lesions may be present

CankerTreatment

Eliminate infected trees from the stand

Prevention avoid scaring trees discard infected trees

RustWhite Pine Blister

fungus disease that contain different spores; effects trees, currents, and gooseberries.

White Pine and Oak is very susceptible

Fusiform fungal disease that

affects Southern Pine and some Oak.

Rust continued...Symptoms

spotted red or brown discoloration of stems and/or leaves

may infest in cones, needles, and stems of conifers

infest only leaves of certain hardwoods

Treatment/Prevention fungicidal treatments plant resistant

varieties rid host plants

** All fungi that causes rust spends its live on two different unrelated host plants

WiltCause

fungus invades and grows in the vessles of the xylem tissue.

Why is this harmful?

EX) Dutch Elm Disease is a form of wilt.

Treatment/Prevention Eliminate insects as

they spread disease discard infected trees be award of root graft

• tree roots grow together underground

** Notice that the oak trees affected by wilt will drop their leaves in the middle of summer.

All three trees in picture show signs of wilt

Sunscald

Cause direct sunlight for

extended amount of time

freezing temps followed by a few days of hot sun in late winter/early spring

Symptoms bark damage color change

Prevention/Treatment None weather related

Insects

Types of Damage Bark Borers Defoliators Root Feeders Terminal Feeders Sucking Insects

Bark Borers

Bore tunnels into bark and woody parts

Female lays eggs in tunnelsLarvae feed on xylem and

phloem tissues

Why is this a big deal?

Defoliators

Insects feed off leaves and needlesFew insects can completely remove foliage

from tree in a single seasonHow does this affect the tree?

Birch, Maple (both black and sugar)

Root Feeders

Destroy the rooting tissue when tender and prevent growth.

Insects include: wireworms, grubs, weevilWhy is this a concern?

Terminal Feeders

Insects that feed on terminal leaders terminal leaders determine which way a

branch will grow

Cause deformities in branches and quality of trunk is reduced.

Insects include: Pine moth and weevil

Sucking InsectsInsects equipped with mouthparts

that imbed into the leaves and suck out all the chlorophyll and produce honeydew.

Why is this bad??Insects include: Aphids, mites,

leafhoppers, lice, scales, cicadas, spittlebugs

Affects all trees

Air Pollution

Abiotic disease caused by Sulfur and Nitrogen compounds given off by exhaust fumes and factories

Damage occurs in leaves and effects photosynthesis

How can we control these problems?

Mechanical/Biological Control remove dead, decayed trees invite birds into territory introduced predator insects ex)ladybug, ants

Chemical Control insecticides, fungicides must be careful when applying

Integrated Pest Management

IPM makes use of all methods in a safe way

depends on the use of natural insects first then adds other defense mechanisms

Encourages genetically engineered resistant crops to be planted