Abiotic Factors

1
Forest Ecology

• Forest Ecology The relationship between members
  of the forest community or between members of the
  community and their environment.
• Autecology The relationship between an
  individual organism and its environment.
• Synecology The relationship between communities
  of organisms and their environment.
• Ecosystem Organisms and their environment
  comprise an ecosystem.

2
Components of the Forest Habitat

• Forest Soils - The growth medium for trees.
  Can be used to define growth potential of
  different tree species.
• Climatic Factors - Define the limits of where
  trees will grow.
• Abiotic Factors
• Biotic Factors

3
Forest Soils

• Soil profiles - comprised of horizons
• Soil horizons - help define soil characteristics
• Structure and composition - define engineering
  and trafficability water-holding capacity.
• Fertility - defines growth potential
• Water holding capacity - defines growth
  potential.
• Site Index - defines growth potential of a soil.
  Specifically measured in feet of growth at a base
  age...

4
Climate

• Light and Temperature - Duration of daylight,
  temperatures define growth or even the presence
  of a species - not exclusive to trees!
• Elevation and Aspect - Aspect, or which direct
  the sidehill faces, significantly affects growth
  and species. Elevation, how high above sea level
  a site is, defines species presence as well.
• Precipitation - Patterns of precipitation affect
  species presence - Examples?

5
Abiotic Factors

• Perturbations - Either natural or man-made.
• Natural - Fire, wind, erosion, avalanche, flood,
  drought, volcanic eruption
• Man-made - Harvest, arson, development,
  road-building, etc...

6
Biotic Factors

• Trees - Trunk, roots, crown
• Understory - Shrubs, seedlings, etc
• Wildlife - Animals, birds, amphibians, fish, etc
• Insects - Various bugs reduce debris, act as food
  sources, etc...
• Soil Organisms - fungi, bacteria, mold...

7
Forest Ecosystems

• Forests - Biotic communities characterized by
  woody plants of greater than human height
• All parts of the forest are interactive in
  nature, e.g. Nature abhors a vacuum!
• Ecosystems can be balanced or unbalanced...

8
Forest Competition

• Trees are typically the dominant biotic element
  in the forest ecosystem.
• Competition limits how many trees can survive in
  a given area.
• Competition exists for water, nutrients, and
  light. This is typically true for all plants..

9
Forest Competition

• How many trees per acre do we typically plant in
  West Virginia?
• How many do we plant in the South?
• If we started with 1000 seedlings per acre at age
  1 in the life of a forest, how many would we have
  at age 50? At age 100?

10
Management Affecting Competition

• What happens if we have an understory of 1000 red
  oak seedlings per acre in a mature forest and do
  nothing?
• What happens if we cut away some of the
  understory and allow openings for the seedlings?

11
Forest Succession

• Primary succession - Establishing plants on bare
  soil.
• Secondary succession - plant invasion on sites
  already covered with vegetation.
• These are starting points on a long journey of
  succession...

12
Succession

• Certain species of trees grow better on open
  sites - Shade intolerant
• Other species grow better under a canopy - Shade
  tolerant
• Some species of trees typically appear at the
  outset of forest development tulip poplar,
  locust, etc...

13
Succession

• With age, trees will die and be replaced by
  long-lived trees and trees that are more shade
  tolerant.
• Expect perturbations that will affect the forest
  community
• With age comes disease, poor growth, and the
  potential for high mortality...

14
Age

• Some trees live less than 100 years - tulip
  poplar, some pines
• Others live to be 400 to 500 years - Oaks...
• Still others will make it to 1000 years - Jeffery
  pine
• With aging trees, we see changes in the
  understory

15
Uses After Death...

• Trees can be harvested long after they die
• Dead standing trees will create snags that
  attract insects, then birds and small mammals,
  then larger nesting birds and animals
• Dead fallen trees create feeding sites and homes
  for a host of insects and other creatures in the
  forest...

16
Demands from the Public

• Different approaches to forestry not based on
  scientific principles of growth, but on the way
  the forest looks at the end of treatment.
• Protection of climax forests.
• Emphasis on creating late successional
  old-growth conditions in young stands (50 to 60
  yrs old)

17
Questions...

• What is a virgin forest?
• What is old growth?
• What is Forest Ecosystem Management
• Do trees grow back after you harvest them?
• Should we harvest old trees?

18
Classifying Trees

• Hardwoods and softwoods
• Angiosperms and gymnosperms
• Common Names
• Scientific Names - Linneaeus, Species Planatarum
  (1753) Latin Names
• Forest Classes - Mixed forest, shade tolerant,
  etc..
• Crown Classes - Dominant, Co-dominant,
  Intermediate, and Suppressed...

19
Silviculture and Forest Ecosystem Management

• Silviculture - All management activities that
  help to develop a socially determined form of
  forest.
• Forest Ecosystem Management - Mans efforts to
  manage a complex biological system comprised
  predominantly of trees. Complex solutions for
  complex problems...

20
Stages of Silvicultural Management

• Harvest
• Site Preparation (optional)...
• Reproduction (optional)...
• Intermediate Operations (optional)
• Commercial Thinning (optional)
• Harvest...

21
Ecosystem Management

• Rarely practiced by private landowners.
• Predominantly emphasized by the USDA Forest
  Service.
• Working to maintain healthy and holistic forest
  ecosystems
• Excludes or minimizes the potential for
  production forestry.

22
Ecosystem Management

• Significant emphasis on what looks right,
  rather than the use of scientific techniques
• As stated in the textThe forest no longer
  looks like a forest.
• Some benefits - Downed woody debris, snags, not
  green tree retention...

23
Adaptive Management

• Great idea - Adapting management to handle
  constantly changing forest conditions to meet
  societal needs or demands on the forest
• Not practiced, particularly in the West where it
  was originally conceived. Typically on public
  lands and bogged down by red tape...

24
Maintaining Forest Health

• Remove fire from mature stands of conifers in the
  West.
• Note continued in-growth of weed species on
  forest.
• Note significantly higher densities of these weed
  trees in forest.
• Note our failure to manage the forest in any
  effective manner
• Watch forest burn...