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
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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
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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”
Appalachian
Plateau
Piedmont
Ridge&
Valley
Coastal Plain
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
You are here!
The old way..
Online Soil Survey
http://websoilsurvey.nrcs.usda.gov/app/
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
north
B
A
west
east
south
Solar Radiation
What would the line look like for a
south, north, and east facing slope?
6 a.m.
Noon
6 p.m
South-facing
Slope
North-facing
Slope
Effect of Aspect on Site Quality
Quantity of biomass produced from an acre of woodland
depends upon the site quality and is similar to farm crops.
Principles of Forest Ecology
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Site Quality
Shade Tolerance
Forest Succession
Plant Competition
Stand Development
Role of Fire, Insect & Disease, and Herbivory,
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
D
B
H
0%
50%
100%
Percentage Sunlight
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
Full Sun
Tolerant
Full Shade
Virginia 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
Principles of Forest Ecology
•
•
•
•
•
•
Site Quality
Shade Tolerance
Forest Succession
Plant Competition
Stand Development
Role of Fire, Insect & Disease, and Herbivory,
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.
Honeysuckle
Grapevine
Invasive and natural
species can take over
Kudzu
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.
80
Number of lepidopteran species
70
60
50
40
30
20
10
0
Native Woody
Non-Native Woody
Forest succession & wildlife habitat
Principles of Forest Ecology
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•
•
•
•
•
Site Quality
Shade Tolerance
Forest Succession
Plant Competition
Stand Development
Role of Fire, Insect & Disease, and Herbivory,
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
Leaves use sun
and water to
produce food...
- More leaves…
- More food…
- More diameter
growth...
25 years
25 years
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.
Principles of Forest Ecology
•
•
•
•
•
•
Site Quality
Shade Tolerance
Forest Succession
Plant Competition
Stand Development
Role of Fire, Insect & Disease, and Herbivory,
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
We measure the density or stocking of
the forest using basal area?
Basal area is the sum of the cross-sectional
area of tree stems 4.5 feet above the ground
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
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–
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
Principles of Forest Ecology
•
•
•
•
•
•
Site Quality
Shade Tolerance
Forest Succession
Plant Competition
Stand Development
Role of Fire, Insect & Disease, and Herbivory,
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
Southern pine beetle
Invasive species
Deer browsing
City of Baltimore, Reservoir Forests
Example: intense deer browse leads to the
disruption of ecological processes
• No seedling regeneration
in the majority of
understory plots
– Prettyboy…..
– Liberty……..
– Loch Raven..
84%
74%
63%
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.
Principles of Forest Ecology
•
•
•
•
•
•
Site Quality
Shade Tolerance
Forest Succession
Plant Competition
Stand Development
Role of Fire, Insect & Disease, and Herbivory,
How do we put all this together to make
recommendations for management activities?
What History
Are
You Writing?