State Competition – Forestry Information

Exotics and Invasives• Emerald Ash Borer (EAB)– It has been found in these

counties: • Ramsey (St. Paul, Shoreview)• Hennepin (Minneapolis)• Houston (LaCrescent)• Winona (Great River Bluffs

State Park)– These counties have been

quarantined, meaning not movement of tree materials of any type (firewood, branches, logs, bark chips)

– There are about 998 million ash trees in MN

Exotics and Invasives• Emerald Ash Borer (EAB)– Look for these signs:

• Larva – creamy white and legless; flattened bell-shaped body segments

• Epicormic Shoots – sprouts growing from roots and trunk have larger than usual leaves

• Serpentine galleries – the larvae feeding leave behind serpentine tracks in the wood

• D-shaped holes – adults emerge out of D-shaped hole

• Canopy dieback and death – due to lack of nutrient exchange

• Splitting of bark• Increased woodpecker activity – indicator

of dead wood and insect larvae infestation

Exotics and Invasives• Gypsy Moth– From Europe – Male moths are brownish gray while

females are white– Caterpillars have 5 pairs of blue dots

on the back and 6 pairs of red dots– Kills trees by caterpillars defoliating

the tree (removing leaves)– Trees it impact the most are aspen

and oak– Moths are mostly found on east coast,

but have moved to midwest• The 4 most southeastern countiesi in MN

have been added to the Slow-the-Spread Program

Exotics and Invasives• Gypsy Moth– Managing the Moth

• Btk – a bacteria that can kill certain butterflies and moths. This can be applied in a spray; However, it can kill other species, so not used liberally

• Dimillin – synthetic hormone sprayed that inhibits the molting in immature insects; Not used by government, since it is very bad for aquatic species

• Disparlure – a pheromone sprayed over leaves to confuse males from finding females, reducing matings

• Forest Management– Encourage mixes of species and diverse

trees, to avoid large defoliations– Do selective cutting to reduce competition

and keep trees healthy– Selective cutting for infested trees

Tree Basics• What tissues are in a tree?– Xylem – brings water and

nutrients from roots upward• Innerwood or Heartwood – dead

xylem cells found in center of tree – provides support

• Sapwood – living xylem cells– Cambium – thin layer of cells

between xylem and phloem that divide to make new xylem and phloem

– Phloem – moves sugar from leaves to roots• Inner Bark –made of living phloem;

stay alive for 1 year• Outer Bark – made of dead phloem

cells and protects the tree

Tree’s Life - Spring• As it warms, sap rises from the

roots to branches (which is when maple syruping occurs by humans)

• Buds bloom and leaves come out• New tissue is added to ends of

twigs– Trees grow taller from the ends of

the twigs…not from the trunks• Each year the tree trunk and

branches get wider. The rapid spring growth is seen in springwood (which are the light colored rings of a tree cookie)

Tree’s Life - Summer• In the summer, the tree slows in

growth. Less xylem cells are laid out and this makes a darker ring of growth. This is called summer wood

• Trees germinate in the summer– Water softens seed coat and expands

the food of the seed (called the endosperm)

– The embryo uses the endosperm energy to push a stem (plumule) up and a root down (radicle)

• Photosynthesis occurs, which makes sugar and oxygen – Oxygen is released into air out of holes

in the underside of the leaf; These are called stoma or stomata

Tree’s Life - Fall• Photosynthesis stops and green color of

chlorophyll subsides, revealing other pigments– Carotenoids – make yellow, orange,

brown– Anthocyanin – make red, purple,

crimson• What makes goods fall colors?

– Related to temperature and moisture conditions during loss of chlorophyll

– Sunny warm days allow sugar production; cool, non-freezing nights prevent sugars from moving in tree

– Lack of moisture reduces frequency and length of fall colors

• Conifers do not lose needles as waxy layer prevents water loss for needles

Tree’s Life - Fall• Deciduous trees make abscissic acid which forms

a membrane between the leaf and twig• The abscission layer formed blocks movement of

sugars out of leaf and eventual seperation of the leaf from the tree– Oak trees have a loose and weaker abscission layer,

which is why oaks often keep leaves all through fall and winter

• Other tissues of the tree harden

Tree’s Life - Winter• Trees also have to avoid frostbite (the expansion

of water in cells, causing death)• Ways to avoid frostbite– Supercooling

• If there is nothing in the cells for crystals to form on, then solids cannot form – so some trees clear their cells of these materials that cause crystal formation, allowing cells to go below zero but still stay liquid

• Red Oaks do this– Extracellular Freezing

• Allowing liquids to seep out of the cell into space between cells. This allows liquids to freeze, but not harm the inner cell

How Do Trees Reproduce?• Seeds• Sucker Sprouts (form of cloning)

– When a new tree grows from the roots of another tree

– Example Tree: Aspen (one reason why they sprout so quickly after harvesting)

• Stump Sprouting (form of cloning)– When new trees grow from stumps – Example Trees: Oak, maple, birch

• Layering (form of cloning)– When a low hanging branch touches the

ground– The branch roots and forms a new plant– Example Trees: Black spruce, balsam fir,

white cedar

Minnesota Forests Today• About 1/3 of MN is forested– This is about 16.3 million acres– Harvest is prohibited on 1.1 million acres (most of this

is in the Boundary Waters Canoe Area)– The total amount of timberland (harvestable land) is

15 million acres• 54% of this is on public land

• Minnesota has more aspens than any other tree (about 1/3 of all trees)

• Aspen-Birch is most common forest type, then spruce-fir

Minnesota Forests Today

• Trends in MN forests– 36% of all forest land is on private lands; 27% is

on state lands, and 17% on federal lands– Forestry brings in 6-7 billion dollars a year and

employs over 40,000 people in MN

Tree/Forest Services

• Cleans the Air– Average tree absorbs 10 lbs of pollutants from the

air each year– One acre of trees:• uses up 6 tons of CO2• Produces 4 tons of oxygen (enough for 18 people)

• Cleans the Water– 100 mature trees catch about 77,000 gallons of

rainwater each year

Tree Cookies/Dendrochronology• Dendrochronology – telling the

history of the tree from its rings and other evidence– Compression Wood – when one

side of tree has greater growth than other (either from competition on one side or wind/elements hitting one side)

– Fire Scars – black mark with warped rings around the site for years after

– Dead Branch Scars – disruption in rings for a few years, then eventually full rings grow around the dead site again

Silviculture

• The art and science of managing forests

Working Trees

• The concept of working trees is that trees provide many different environmental services. You will want to know each of these!– Many of these services are in regards to

agroforestry – the practice of using trees/shrubs in agricultural settings to get environmental, economic, and social benefits

Energy Conservation and Trees• Trees do evapotranspiration (same thing as

transpiration)– This cools the air and makes local microclimates lower

in temperature• Trees provide shade to reduce heat island effects• Trees absorb light rather than reflect it• Trees can be positioned to reduce air

conditioning and heating costs• Trees can be used for energy sources (fuelwood)

or developed into other energy sources (like biofuels)

Working Trees – Reducing Energy Use

• Use trees as windbreaks– Can reduce energy costs for heating cooling by as much as

20-40 %– Act as snow fences, reducing need for snow removal and

energy costs with that– Reduce wind erosion and increase irrigation efficiency –

meaning higher crop yields• Use trees as riparian forest buffers– This means plant trees around water sources (3-5 rows

needed at least)– Can be used a supplemental income source for harvesting

the trees (then need 7 rows)– They intercept ag runoff

Working Trees – Reducing Energy Use

• Start forest farming– Can make money and provide wildlife habitat and

environmental services that go with trees• Silvopasture– Combining trees and forage/livestock production– Manage trees for long term timber and understory for

livestock production• Alley Cropping– Growing crops for yearly income and trees/shrubs to get

long term income– Some trees/shrubs could be used to develop alternative

energy sources as well.

Working Trees – Community Benefits

• They capture and filter runoff and nonpoint source pollution

• They provide soil stability and streambank stability – less chance of both of these washing out

• They phytoremediate – plants and soil organisms detoxify pollutants and break them down

• Trees add biodiversity to an area• Trees are wildlife habitat for the community• Trees act as a screen to buffer noise and ugly things,

like walls or fences• Trees sequester carbon and store it.

Working Trees – Community Benefits

• Trees clean the air – attract and absorb PM, NOx, SO2, ozone, smog• The intercept stormwater and absorb it

– A 32-foot tall trees reduces stormwater runoff by 327 gallons• Can be a way to treat wastewater before effluents are released• Can act as a barrier to wind movement for landfills – help keep

things in the landfill• Act as a living snowfence, which lessens the amount of snow

removal needed• Increase property values and liklihood of resale of property• Greener areas also experience less crime, perhaps due to

community pride