Dendrology 101 & Common Trees of Texas · 2019. 12. 17. · Ecology Defined The study of living...
Transcript of Dendrology 101 & Common Trees of Texas · 2019. 12. 17. · Ecology Defined The study of living...
© Christopher Ebling 2008-2011. All rights reserved.
Forest Ecology
Chris EblingTexas Master Naturalist
© Christopher Ebling 2018. All rights reserved.
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© Christopher Ebling, 2008-2011. All rights reserved.
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Topics
◼ What is ecology, and specifically forest ecology?
◼ What is an ecosystem, and specifically a forest ecosystem?
◼ Processes associated with living and nonliving elements within a forest ecosystem.
◼ Basic components and structure of a forest ecosystem.
◼ Different forest ecosystem/types and factors that contribute to the differences.
© Christopher Ebling, 2008-2011. All rights reserved.
Why Study Ecology?
◼ As Master Naturalists you have learned about
❑ Geology
❑ Ornithology
❑ Entomology
❑ Herpetology
❑ Climatology
◼ Ecology is a meta-science that pulls it all
together
❑ Describes interrelatedness between disciplines
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As master naturalists, our role is to place our audience within
this web of relationships
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Ecology Defined
◼ The study of living organisms and their relationship
to their environment
❑ Greek oikos (house) + German logie (study)
❑ Physical environment
◼ Geography, climate, soils, etc.
❑ Intra-species relationships
◼ Social structure
❑ Interspecies relationships
◼ Competition
◼ Forest Ecology – study of the relationships between
living organisms and non-living factors in a forest
© Christopher Ebling, 2008-2011. All rights reserved.
What is an Ecosystem?
◼ An ecosystem is a
dynamic set of living
organisms (plants,
animals and
microorganisms) all
interacting among
themselves and with the
environment in which
they live (soil, climate,
water and light).
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What is an Ecosystem?
◼ An ecosystem does not
have precise boundaries
❑ As small as a pond or a
dead tree
❑ As large as the Earth itself
◼ An ecosystem can also
be defined in terms of its
vegetation, animal
species or type of relief
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Forest Ecosystems
◼ Forest: "an ecosystem characterized by a more or less dense and extensive tree cover, often consisting of stands varying in characteristics such as species composition, structure, age class, and associated processes, and commonly including meadows, streams, fish, and wildlife❑ Forests include special kinds such as industrial
forests, non-industrial private forests, plantations, public forests, protection forests, and urban forests, as well as parks and wilderness."
- Society of American Foresters
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Forest Energy Flow
◼ All terrestrial ecosystems
depend on solar energy
as the primary energy
source.
❑ Others energy sources?
◼ Primary productivity is the
result of energy captured
by producers, such as
plants.
❑ Some of this energy is lost
when producers use
sunlight energy for
respiration.
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“Energy Flows, Nutrients Cycle”
First Law of Thermodynamics!
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Forest Energy Flow
◼ Only a portion of the
energy captured by
producers is passed on to
consumers.
❑ Rule of thumb – 90% of
energy is lost in transfers
between trophic levels.
❑ Consumers also lose
energy due to respiration.
◼ Note that the energy flow
through an ecosystem is
one way.
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“Energy Flows, Nutrients Cycle”
Copyright ® 1999. Elizabeth Anne Viau
© Christopher Ebling, 2008-2011. All rights reserved.
Forest CyclesThe Hydrologic Cycle
◼ All water begins in the oceans
◼ All water returns to the oceans
◼ What is the most potent
common greenhouse gas in
our atmosphere?
◼ What happens as the
atmospheric temperature
increases?
❑ Remember your physics!
❑ Warmer air can hold more
gaseous water
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“Energy Flows, Nutrients Cycle”
Source: USGS
© Christopher Ebling, 2008-2011. All rights reserved.
Forest CyclesThe Nitrogen Cycle
◼ Most of the atmosphere is comprised of N2
◼ Most of the nitrogen in the atmosphere is unavailable for use by organisms. ❑ The strong triple bond between
the N atoms in N2 molecules makes it relatively inert.
◼ For plants and animals to be able to use nitrogen, N2 gas must first be converted (“fixed”) to more a chemically available form such as ammonium (NH4+), nitrate (NO3-), or organic nitrogen (e.g. urea -(NH3)2CO).
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“Energy Flows, Nutrients Cycle”
© 1999-2007 Michael Pidwirny
© Christopher Ebling, 2008-2011. All rights reserved.
A Digression
◼ Gliricidia sepium
❑ A deciduous tree in the
Leguminosae family
◼ Used in Malawi as part of
agroforestry initiatives
❑ Fixes nitrogen in the soil
❑ Loses its leaves during the
crop season
❑ 3X to 4X increase in maize
production!
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Forest CyclesThe Carbon Cycle
◼ The incorporation of carbon dioxide into living tissue by photosynthesis and return to the atmosphere through respiration, the decay of dead organisms, and the burning of fossil fuels
◼ Carbon is stored in major sinks❑ Organic molecules in living and dead
organisms found in the biosphere;
❑ Carbon dioxide in the atmosphere;
❑ Organic matter in soils - permafrost
❑ Lithosphere as fossil fuels and sedimentary rock deposits such as limestone, dolomite and chalk;
❑ The oceans as dissolved atmospheric carbon dioxide and as calcium carbonate shells in marine organisms.
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“Energy Flows, Nutrients Cycle”
Carbon Storage
CO2 Cycle
© 1999-2007 Michael Pidwirny
Source: Youcontrol-cllimatechange.co.uk
© Christopher Ebling, 2008-2011. All rights reserved.
Carbon Storage
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Carbon Storage
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Carbon Transfer & Climate Change
◼ What is the problem with burning fossil fuels?❑ Massive release of
stored carbon
◼ What happens as the oceans warm?❑ Remember your
physics!◼ Reduced capacity to hold
dissolved gasses
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Vertical Forest Structure
Forests Ecosystems
are
Three Dimensional
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Forest Structure – Emergent Layer
❑ Dominant species
that extend through
the canopy
◼ Evident in rainforests
◼ White Pine forest in
Northern Michigan
❑ What are the
advantages and
disadvantages of
being emergent?
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Forest Structure - Canopy
❑ Highest continuous
level in the forest
❑ Contains mature
trees
❑ What is the
advantage of being in
the canopy?
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Forest Structure - Understory
❑ Contains
◼ Tree saplings
◼ Small shade-tolerant
trees
❑ dogwood, redbud
◼ Tall shrubs
❑ What is the strategy
of understory trees?
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Forest Structure – Herb/Fern Layer
◼ The herb/fern layer
❑ Ranges from the
ground surface to
about 3'
◼ Tree seedlings,
herbs, ferns,
grasses
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Forest Structure – Litter Layer
❑ Decaying plant and
animal matter
❑ Fungi, mosses &
lichens
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Does the forest ecosystem
end at the forest floor?
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Soil Characteristics
◼ Soil Horizons
❑ A layer parallel to
the soil surface, whose
physical characteristics differ
from the layers above and
beneath.
◼ Soil Structure
❑ The way individual particles of
sand, silt, and clay are
assembled.
◼ Affected by:❑ Basal geology
❑ Climate
❑ Water Movement.
❑ Organic Matter Content
❑ Soil Organisms.
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© 2015 Larry Cooper.
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Tree Communication
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Tree Communication
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Trees Communicate via Root Systems and Fungal Networks
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Horizontal Forest Structure
◼ Stand density
❑ A measure of the
stocking rate of trees
in a forest
❑ Measured by:
◼ Trees/acre
◼ Basal area/acre
◼ Crown cover
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Forest Succession
◼ Forest succession is the temporal transition of vegetation societies at the same place after major changes in environmental conditions (e.g. glaciation, fires, clear cut logging).
◼ If it starts from a vegetation-free area, it passes through a certain sequence of societies initiated by pioneer-societies, followed by intermediate stages up to the final climax society.
◼ The climax society can only develop if no other disturbance interrupts the development.
◼ Succession has a great impact on wildlife populations❑ White Tailed Deer – Elk
❑ Kirtland’s Warbler◼ Require 4 to 20 year old Jack Pine trees for nesting
◼ Dependent on fire to reset forest succession❑ Jack Pine only reproduce after a fire.
Time
Forests Exist in Four Dimensions – Space & Time
Source: Ohio State University Extension Service
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Factors that Affect Forest Development
◼ Climate
❑ Temperature
◼ Range and seasonality
◼ Eg. Texas vs. Brazil
❑ Rainfall
◼ Amount and seasonality
◼ Eg. Texas vs. Brazil
◼ Sunlight
❑ Intensity and seasonality
◼ Rainforest vs. Northern Boreal
Forest
◼ Geography
❑ Latitude
❑ Altitude
◼ Mimics latitudinal differences
◼ Davis mountains
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Factors that Affect Forest Development
◼ Geology
❑ Soil type
◼ Rocky, sandy, acidic, basic,
nutrient availability, etc.
◼ Eg. Transition from
Blackland Prairie to Piney
Woods.
◼ Disruption
❑ Fire
❑ Animal/insect activities
❑ Human activities
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Texas Forest Facts
◼ Texas has more than 12 million acres of forestland concentrated in 43 counties in East Texas
◼ Sixty-two percent of Texas' forestland is owned by non-industrial private landowners.
◼ 32% is owned by industry.
◼ The public (federal or state forests) owns the other 6%
❑ Four National forests
❑ Five State forests
◼ Over 200 tree species are considered native to Texas
Source: Texas Forest Service
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Texas Forests
◼ Texas National Forests
❑ Angelina
❑ Davey Crockett
❑ Sabine
❑ Sam Houston
◼ Texas State Forests
❑ I.D. Fairchild
❑ Masterson
❑ John Henry Kirby
Memorial
❑ E.O Siecke
❑ W. Goodrich Jones
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