No Slide Title - University of Maryland Extension...Principles of Forest Ecology • Site Quality • Shade Tolerance • Forest Succession • Plant Competition • Stand Development

Principles of Forest Ecology and Management or…

“Forensic Forestry”

Reading the Land

Jonathan Kays University of Maryland Extension

Where Do We Start?

Think Like A Plant

Act Like A Plant

Thinking and Acting Like a Plant

• What is your favorite plant? – Where does it grow? – How do you describe that place? – What is important?

What Does a Plant Need?

• Light • Water • Nutrients

Principles of Forest Ecology

• Site Quality • Shade Tolerance • Forest Succession • Plant Competition • Stand Development • Role of Fire, Insect & Disease, and Herbivory,

Site The environment or system supporting a

forest, which influences trees and plants growing there.

The sum of Soil, Topography, Climate,

Plants, and Animals

Forest Succession on a Site Predictable changes in plant communities

as the competing organisms respond to and modify the environment. These changes will vary depending on the site.

Site is More Important than the Vegetation

• It is more fixed • It is more stable • It is more easily defined • Reflects disturbance

– Strip mine (extreme) – Pasture (subtle) – Harvesting (either)

• Look for Clues!

Maryland Physiographic Regions or “Sites”

Coastal Plain Ridge& Valley

Appalachian

Plateau Piedmont

Great Valley Blue Ridge

Dominant Forest Communities

Garrett County – Alleghany Plateau

Allegany County - Ridge and Valley

Piedmont Region

Coastal Plain – Southern Maryland

Coastal Plain - Eastern Shore

Forest Soils – Foundation of Site Quality “Healthiest Soils in the World”

Soil profile How does soil develop or form? From the bottom or the top? Where is the older soil?

Plow Layer

Root Mat that holds soil in place

Wetland soils contain organic material, exist with little oxygen, and have developed specialized

ecosystems compared to upland areas.

Consider soils when selecting tree species to plant. Is soil well-drained or poorly drained? Black walnut

does poor in wet areas.

Where are most of the tree roots?

Most tree roots are found within the top 12 inches of soil

Online Soil Survey http://websoilsurvey.nrcs.usda.gov/app/

The old way..

You are here!

Mineral Cycling

• Pine forest – slow turn around • Hardwood forest – faster turnaround

Faster recycling of nutrients in hardwood

forests compared to pine. WHY?

Best Management Practices protects

the root mat

Slope Position

Are trees larger on the upper or lower slope?

Climate, soil, available water, and nutrients all affect how well a tree grows. If minimum requirements are

not met, a tree may not grow in a given area.

Oaks are better adapted to dry and shallow hilltop soils, while yellow-poplar trees are

found on more fertile lower slopes

Poor Site Good Site

Certain trees adapt to special conditions

Site Indicator Species

Aspect Direction the slope is facing

south

west east

north

A B

Solar Radiation What would the line look like for a

south, north, and east facing slope?

6 a.m. Noon 6 p.m

Effect of Aspect on Site Quality

South-facing Slope North-facing

Slope

Quantity of biomass produced from an acre of woodland depends upon the site quality and is similar to farm crops.



Shade Tolerance is the ability of a plant to grow in the shade

• Intolerant Species - intolerant of shade and must have full sunlight to grow

• Tolerant Species - tolerant of shade – does not require full sunlight to grow

• Intermediate tolerance - can grow in partial sunlight or shade

Tolerance, Sunlight, Growth

0% 50% 100% Percentage Sunlight

D B H

Intermediate tolerance – trees that can establish themselves in the understory, but require full

sunlight to mature -- Oak in this example

Tolerance of Common Forest Trees

Intolerant Intermediate TolerantFull Sun Full ShadeVirginia pine White pine Hemlock

Loblolly pine Hickories Beech

Yellow-poplar Yellow & bl birch Sugar maple

Scarlet & black oak White & red oak Red maple

Black walnut Chestnut oak Silver maple

Green ash Red oak Basswood

Red cedar White ash American holly

Grey birch



Forest Succession Predictable changes in plant communities as

the competing organisms respond to and modify the environment.

Principle: All natural areas change over time,

whether or not you do anything to them.

Five Stages of Secondary Forest Succession

Stage 1 Herbaceous species

Stage 2 - Old Field

Stage 2 - Old Field of red cedar and goldenrod. It may be beneficial to maintain old field habitats by cutting down invading trees, which can

maintain a diversity of habitats on the property.

Invasive and natural species can take over

Honeysuckle

Kudzu

Grapevine

Old field red cedar being overtopped by shade intolerant tree species (yellow-poplar in this case).

Stage 3 Tree crowns close, sunlight disappears, resulting in dieback of ground vegetation. Poor wildlife value for this stage of succession.

Stage 4

Stage 5 Old Growth

Early Successional Species Vary by Region

Forest succession is the progression of plant communities that begins with shade intolerant plants and ends up with shade tolerant plants.

Virginia Pine early successional forest common on poor soils.

Example of an early successional Virginia pine forest that is dying. Beech trees (a late successional species) have established themselves in the understory and will form the new forest.

Tree Planting--Pushing succession ahead

Forest Harvesting:

Effect on Succession?

Important Role of Native Species

• Native plants and insects have developed evolutionary relationships. Caterpillars & insects provide protein sources for birds and mammals.

0

10

20

30

40

50

60

70

80

Native Woody Non-Native Woody

Num

ber o

f lep

idop

tera

n sp

ecie

s

Forest succession & wildlife habitat



What Do Plants Compete For?

• Light • Water • Nutrients

Are these trees different ages?

Is tree size a reliable indicator of tree age? Why?

Tree is a factory ... Leaves use sun and

water to produce food...

More leaves… More food… More diameter growth...

The dominance of a tree refers to the position of its crown relative to other trees in the canopy. In even-aged forests, the

more dominant trees have won the competition for light.

Forest Thinning - improve growth & species composition, not regeneration

25 years

25 years

- More leaves… - More food… - More diameter growth...

Leaves use sun and water to

produce food...

Live crown ratio (LCR) is the ratio of the foliage canopy to the total height of the tree. - Hardwood – 5065% - Pine 70-90%

Epicormic Branching

As buds under bark are exposed to sunlight, they grow and form new branches on the tree bole and can reduce quality. Do not open the forest canopy too much.

Leaving the proper stocking produces better growth and little

epicormic branching.

Picture: woodland after a sustainable

harvest.

Unsustainable harvest removed dominant and best trees and left the rest. They go by the names of diameter-limit cutting, selection harvest and high-grading.

This amounts to starting over.



Regeneration is the key: Different species have different regeneration strategies

Some species like yellow-poplar, ash and maple need bare soil to germinate seeds…

Heavy seeded species: * Oak * Hickory * Walnut

Slow and steady…

Stump sprouts from cut hardwood stumps are the most vigorous source of hardwood forest regeneration.

Stump sprouting reduces with stump diameter

If stumps are cut low, sprouts from the root collar will grow into quality trees (right).

Stand Development: Tree Density increases over time Year 1: 10,000 stems/ac Year 15: 1,000 stems/ac

Volume Growth Per Tree or Acre is Controlled by Tree Density (or Stocking)!

Well spaced trees optimize volume growth

Basal area is the sum of the cross-sectional area of tree stems 4.5 feet above the ground

We measure the density or stocking of the forest using basal area?

BA in a Few Big Trees or Many Smaller Trees

Development of vertical stratification as trees die,

holes are filled, others seed in.

Stand Development • A function primarily of

– site quality – Past history – current practices (grazing, for example) – species composition

A photographic history from the Allegheny Plateau in Pennsylvania

(1927-1998)

1927

1928

1937

1947

1958

1968

1978

1998

Forests are resilient

60 years later



Smokey Bear Changed the Landscape…

• Fewer low intensity fires • Buildup of fuel in understory –

larger crown fires result • Oak-hickory species lost

ecological advantage

Fire releases nutrients, renews,

and favors certain

tree species

Fire ecology differs by region Apples ‘n oranges

Chestnut Blight changed the forest in the span of a few years in the late 1920’s.

Gypsy moths continue to be a

periodic problem.

Emerald Ash Borer will kill all ash trees

Major disturbances, such as hurricanes, tornadoes, and

wind storms.

Other Disturbances

Invasive species

Deer browsing

Southern pine beetle

• No seedling regeneration in the majority of understory plots – Prettyboy….. 84% – Liberty…….. 74% – Loch Raven.. 63%

City of Baltimore, Reservoir Forests Example: intense deer browse leads to the disruption of ecological processes

Deer overabundance negatively impacts forest regeneration and wildlife habitat for other species. Forest birds that used to

be next in the ground vegetation are no longer found.



How do we put all this together to make recommendations for management activities?

What History Are

You Writing?

Documents

No Slide Title - University of Maryland Extension...Principles of Forest Ecology • Site Quality • Shade Tolerance • Forest Succession • Plant Competition • Stand Development