• TABLE OF CONTENTS
HIDE
 Copyright
 Introduction
 What controls growth?
 Where does growth occur?
 Growth above ground
 Growth below ground
 Palms
 Seasonal growth, lifespan...
 Growth and tree form
 Some examples of the urban environment...
 Conclusion
 Reference
 For more reading about tree...
 Acknowledgments






Group Title: Florida Cooperative Extension Service circular 1093
Title: How trees grow in the urban environment
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00049201/00001
 Material Information
Title: How trees grow in the urban environment
Series Title: Circular
Physical Description: 9 p. : ill. ; 28 cm.
Language: English
Creator: Duryea, Mary L
Malavasi, Marlene M
Florida Cooperative Extension Service
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville
Publication Date: 1993
 Subjects
Subject: Urban forestry   ( lcsh )
Trees in cities   ( lcsh )
Trees -- Growth   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 9).
Statement of Responsibility: Mary L. Duryea, Marlene M. Malavasi.
General Note: Title from caption.
General Note: "Printed 4/93"--Colophon.
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00049201
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: oclc - 28538020

Table of Contents
    Copyright
        Copyright
    Introduction
        Page 1
    What controls growth?
        Page 2
    Where does growth occur?
        Page 3
    Growth above ground
        Page 3
        Page 4
    Growth below ground
        Page 5
    Palms
        Page 5
    Seasonal growth, lifespan and aging
        Page 6
    Growth and tree form
        Page 7
    Some examples of the urban environment influencing growth
        Page 7
    Conclusion
        Page 8
    Reference
        Page 9
    For more reading about tree growth
        Page 9
    Acknowledgments
        Page 9
        Page 10
Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida




/o/


/Urban Forestry








Urban Forestry


1993


How Trees Grow

in the Urban Environment


Mary L. Duryea
Marlene M. Malavasi'


Circular 1093


Introduction

What happens to a birdhouse if you hang it on a
tree and come back in two years? Will it be at
the same height or out of your reach because the
tree has grown? (Figure 1)


By the end of
this article you
will be able to
answer this
question and
others about
how trees grow.

This publication
is for those who
love to plant
and grow trees.
Of course, trees
grow the same
way in the city
as they do in
the country
(physiologically
speaking), but
we will empha-
size tree growth
in cities and
discuss factors
of the urban
environment that


Contents

Introduction
What is tree growth?
What kinds of trees will we be talking
about?
What controls growth?
Where does growth occur?
Growth above ground
Shoot elongation
Leaf growth
Diameter growth
Annual Rings
Bark
Growth below ground
Root elongation
Root diameter growth
New root growth
Palms
Shoot elongation
Root growth
Growth and tree form
Seasonal growth, lifespan and aging
Some examples of the urban environment
influencing growth
Conclusions


affect this growth.


'Extension Specialist and Visiting Professor in the Department of Forestry, University of Florida, 32611.
Florida Cooperative Extension Service Institute of Food and Agricultural Sciences University of Florida, Gainesville John T. Woeste, Dean


UNIVERSITY OF FLOkIAA LNI4ARIES


Figure 1. If a birdhouse is hung on
a tree, will it move up as the tree
grows?


I








I0N WHAT IS TREE GROWTH?

F 3(L To set the stage for our discussion of tree
/0 ? growth we must review some terminology.


SCIEbNCt
LI AR, Y


Trees have 6 organs.
and roots (known
as vegetative
structures) and
flowers, fruits, and
seeds (known as
reproductive
structures). We
will discuss
vegetative growth --
that is the growth
of leaves, stems
and roots.

Tree growth is the
increase in size and
numbers of leaves,
stems, and roots.


These are: Leaves, stems


Environmer
Water Lght Temperature Air


Physiological .
Processes
Photosynthesis
Respiration
Translocation
Water Absorption


SSpecies Variety
SGenetics

Figure 2. Tree growth is influenced
genetics.


WHAT KINDS OF TREES WILL WE BE
TALKING ABOUT?

Trees are seed plants -- that is they reproduce by
seed. They are classified into Gymnosperms
and Angiosperms. Gymnosperms are trees with
seeds that develop on the surface or tip of an
appendage such as a cone. Examples are
cypress and pines. Angiosperms are trees with
seeds borne within structures such as fruits (the
seed is enclosed). Examples are oaks, elms,
maples and palms. We are going to be
describing growth of both gymnosperms and
angiosperms. Also, since we live in Florida,
there's one more division that is necessary and
that is among angiosperms. Palms are
angiosperms and but they are different than
oaks, maples and elms, because palms are
monocots and are related to grasses. Oaks,
maples and elms are dicots. So we will first
talk about growth of gymnosperms and dicots;
then because they grow very differently, we will
have a special section on palms.


What controls growth?


Tree growth is a response to the environment
and to its genetic make-up (Figure 2). The
environment is made up of such factors as
water, light, temperature, air, pests and cultural
practices. These all
impact
physiological
It processes such as
Soil Pests Cultural photosynthesis, and
Practices the final response is
-G that the tree grows
vigorously or
0\ slowly. A tree's
W genetic make-up
T.. also influences the
H way a tree grows.
Genetics means
Family what species it is,
sI what seed source or
variety (did it come
by both the environment and from south Florida
or North
Carolina?), and
which family (who
were its parents?). These genetic characteristics
along with its environment determine how a tree
grows. For
example, the
longleaf pine in
Figure 3a is
growing quite
well. Its i
genetic make-up
and its .
environment are
obviously
compatible and
favorable to
growth.


Yet, Figure 3b
shows another
longleaf pine
which is not
doing so well.
Is this due to its
environment --
shade, water,
fertilizers, etc
or due to its


figure a~tu A .ungeuau pUM
responding well to its environment.























Figure 3b. A longleaf pine growing poorly due to its
genetic make-up and environment.


genetics? It's difficult to separate out effects of
environment and genetics but we can definitely
conclude that they are impacting growth of these
two trees. We will talk more about the
environment and genetics at the end of the
publication in the section, "Some examples of
the urban environment influencing growth".

Where does growth occur?


Growth occurs
in meristems.
A meristem is a
tissue that
contains cells
which have the
capacity to
divide to make
new cells. In
general, during
growth cells
divide, cells
elongate, and
cells
differentiate
into structures
such as roots


0


0 0 0 0 cells divide



0 0 0 0 cellselongate

J cells
0 0 differentiate
and mature
root shoot
Figure 4. In general, during
growth cells divide, elongate and
differentiate.


and shoots (Figure 4).

Meristems can also produce new meristems --
these are called primordia. For example, an


apical meristem in a bud produces new
meristems called leaf primordia -- each single
primordium will grow into a new leaf. Root
primordia grow into new roots.


Growth above ground

Tree growth above ground includes shoot
elongation (height growth), leaf growth, and
diameter growth.

SHOOT ELONGATION

Shoots elongate or grow in height at the tips of
the branches (Figure 5). Apical meristems are
located in the terminal buds at the tips of the
branches. What happens is -- cells at
the apical meristem divide, elongate and
differenti-
ate. The
steps that
we can see Terminal bud
are: (1)
The bud at Area of
the tip of expansion
the branch
opens, (2)
Leaves
emerge
and
enlarge,
and (3)
The area
between
the leaves
expands Figure 5. A small tree showing the
(i.e. the terminal bud (which contains the apical
stem meristem), leaves which have enlarged,
grows). and the area of stem expansion between
Lateral the leaves.
Lateral
(side) buds
grow in the same way but often these are
dormant and do not grow until they are released
after such activities as pruning.

LEAF GROWTH

On the surface of the apical meristem in the
bud, a new meristem is formed. This new
meristem is called a leaf primordium, and this is
where cells divide and grow to form a leaf.























Figure 3b. A longleaf pine growing poorly due to its
genetic make-up and environment.


genetics? It's difficult to separate out effects of
environment and genetics but we can definitely
conclude that they are impacting growth of these
two trees. We will talk more about the
environment and genetics at the end of the
publication in the section, "Some examples of
the urban environment influencing growth".

Where does growth occur?


Growth occurs
in meristems.
A meristem is a
tissue that
contains cells
which have the
capacity to
divide to make
new cells. In
general, during
growth cells
divide, cells
elongate, and
cells
differentiate
into structures
such as roots


0


0 0 0 0 cells divide



0 0 0 0 cellselongate

J cells
0 0 differentiate
and mature
root shoot
Figure 4. In general, during
growth cells divide, elongate and
differentiate.


and shoots (Figure 4).

Meristems can also produce new meristems --
these are called primordia. For example, an


apical meristem in a bud produces new
meristems called leaf primordia -- each single
primordium will grow into a new leaf. Root
primordia grow into new roots.


Growth above ground

Tree growth above ground includes shoot
elongation (height growth), leaf growth, and
diameter growth.

SHOOT ELONGATION

Shoots elongate or grow in height at the tips of
the branches (Figure 5). Apical meristems are
located in the terminal buds at the tips of the
branches. What happens is -- cells at
the apical meristem divide, elongate and
differenti-
ate. The
steps that
we can see Terminal bud
are: (1)
The bud at Area of
the tip of expansion
the branch
opens, (2)
Leaves
emerge
and
enlarge,
and (3)
The area
between
the leaves
expands Figure 5. A small tree showing the
(i.e. the terminal bud (which contains the apical
stem meristem), leaves which have enlarged,
grows). and the area of stem expansion between
Lateral the leaves.
Lateral
(side) buds
grow in the same way but often these are
dormant and do not grow until they are released
after such activities as pruning.

LEAF GROWTH

On the surface of the apical meristem in the
bud, a new meristem is formed. This new
meristem is called a leaf primordium, and this is
where cells divide and grow to form a leaf.








Several meristems on a leaf influence leaf shape


(Figure 6).

Soon after leaves
develop, a new bud
primordium
meristemm) is
formed at the base
of each leaf stem.
Once formed, this
axillary bud has the
capacity to become
a branch, but may
lie dormant for
many years.

DIAMETER
GROWTH


Figure 6. Each leaf has meristems. Rapid cell division at these meristem
determines the final leaf shape.


Between the wood and bark is a thin layer of
dividing cells called the vascular cambium. This
vascular cambium is a meristem which is only a


Figure 7. The vascular cambium produces wood on
the inside and bark on the outside.

few cells thick. This meristem divides, creating
wood on the inside and bark on the outside
(Figure 7). Layer by layer these new cells
increase the diameter of the trunk and branches.
The wood cells are called "xylem" which means
wood in Greek; they carry water and minerals
up from the roots. The bark cells are called
"phloem", meaning bark in Greek. These cells
carry sugars and other materials produced by the
plant.

ANNUAL RINGS

New layers of wood are added each year
between the bark and the previous year's wood.


"early" or "spring" wood.
the
summer
are
smaller,
and this
"late" or
"summer"
wood has
a higher
density
and darker S
color.
Figure 8. Ann
thickness acco
BARK they are forme

All woody
trees have
bark which
protects the tree
from pest
attacks and
environmental
impacts such as
fire and
mechanical
injury. Some
trees have thick
bark that is
resistant to
injury. Others
are easily
injured because Figure
they have thin diameter
bark. Why eventual


ual rings vary in size and
rding to the season when
d.


9. As a tree grows in
r the bark cracks and may
ly slough off.


Regions with high rates
of cell division


Primordium
leaf


Developing leaves


and may be used
to age a tree. In
most parts of
Florida, annual
rings vary in size
and thickness
according to the
season that they
are formed
(Figure 8). Cells
that are produced
in the spring are
larger with thinner
cell walls. These
Share the light
colored rings, and
the wood is called
Cells produced in


These are called growth rings or annual rings


Mature leaf








does bark have ridges and cracks? As the tree
grows in thickness, the outer part has to give,
forming ridges and cracks. Eventually the outer
bark sloughs off (Figure 9).


Growth below ground

Roots can grow in length (root elongation) and
diameter, and new lateral roots can form.

ROOT ELONGATION

At the tip of a root is the root cap (Figure 10).
This cap protects the root and it must be


Lateral
root
primordium


root








Root
cap


Figure 10. A root tip showing the meristem which produces
new cells for root elongation.


constantly replaced as it pushes through the soil.
Behind the root cap is a meristem which
produces new cells for the root cap and for root
elongation. These new cells elongate, divide
and differentiate into root parts. The root grows
in length and pushes through the soil.

ROOT DIAMETER GROWTH

Many people don't think that roots grow in
diameter, but they do! And root diameter
growth is similar to growth in the stem with the
vascular cambium producing wood (xylem) and
bark (phloem). A couple differences between
root and shoot diameter growth are: (1) cambial
growth is much more irregular in roots resulting
in roots that are oval or irregular in cross


section, and (2) there is greater variation in
diameter with age and with horizontal roots
compared to vertical roots.

NEW ROOT GROWTH

Roots can also grow new lateral roots that form
and branch off the main root. Some cells
located in a layer inside the root produce a new
root primordium (Figure 10). This new
meristem divides and elongates pushing the root
out through the parent root. A new lateral root
is formed and grows into the soil.


Palms

There are two major points to be made about
palm growth: (1) Palms only have one terminal
growing point, and (2) Palms do not grow in
diameter as they age. We will talk about how
palms grow taller and grow roots and how the
one bud influences their form compared to other
trees.

SHOOT ELONGATION

The apical meristem lies in a depression at the
crown of the stem (Figure 11). Within this
meristem is a soft mass of leaves and leaf bases.
In this crown there is continuous production of
leaf meristems (primordia). There may be up to
50 meristems in the apex. The leaves grow in


Figure 11. A palm has one apical meristem which
produces all its leaves.


S Crown


Apical
meristem


Leaf
bases








does bark have ridges and cracks? As the tree
grows in thickness, the outer part has to give,
forming ridges and cracks. Eventually the outer
bark sloughs off (Figure 9).


Growth below ground

Roots can grow in length (root elongation) and
diameter, and new lateral roots can form.

ROOT ELONGATION

At the tip of a root is the root cap (Figure 10).
This cap protects the root and it must be


Lateral
root
primordium


root








Root
cap


Figure 10. A root tip showing the meristem which produces
new cells for root elongation.


constantly replaced as it pushes through the soil.
Behind the root cap is a meristem which
produces new cells for the root cap and for root
elongation. These new cells elongate, divide
and differentiate into root parts. The root grows
in length and pushes through the soil.

ROOT DIAMETER GROWTH

Many people don't think that roots grow in
diameter, but they do! And root diameter
growth is similar to growth in the stem with the
vascular cambium producing wood (xylem) and
bark (phloem). A couple differences between
root and shoot diameter growth are: (1) cambial
growth is much more irregular in roots resulting
in roots that are oval or irregular in cross


section, and (2) there is greater variation in
diameter with age and with horizontal roots
compared to vertical roots.

NEW ROOT GROWTH

Roots can also grow new lateral roots that form
and branch off the main root. Some cells
located in a layer inside the root produce a new
root primordium (Figure 10). This new
meristem divides and elongates pushing the root
out through the parent root. A new lateral root
is formed and grows into the soil.


Palms

There are two major points to be made about
palm growth: (1) Palms only have one terminal
growing point, and (2) Palms do not grow in
diameter as they age. We will talk about how
palms grow taller and grow roots and how the
one bud influences their form compared to other
trees.

SHOOT ELONGATION

The apical meristem lies in a depression at the
crown of the stem (Figure 11). Within this
meristem is a soft mass of leaves and leaf bases.
In this crown there is continuous production of
leaf meristems (primordia). There may be up to
50 meristems in the apex. The leaves grow in


Figure 11. A palm has one apical meristem which
produces all its leaves.


S Crown


Apical
meristem


Leaf
bases







sequence with one leaf emerging as a spear at a
time. The meristem at the base of the leaf causes
the leaf to elongate, grow bigger and thicken
and eventually equal the diameter of the palm
stem.

ROOT GROWTH

Root growth occurs near the root cap just as in
gymnosperms and dicots. However, just like
shoot growth of the stem, there is no diameter


diameter growth and then root growth.
However, this growth can occur in any order,
and root growth may be year-round or have two
growing periods per year. Young trees grow


ITime of year
Figure 13. Different parts of trees grow at
different times of the year.


figure zu. numes prouuce a maus o roows v
length but not diameter.


growth of palm roots. The roots remain the
same diameter for long distances (giving the
appearance of a spaghetti-like root system)
(Figure 12). Descending roots are for
anchorage. Most of the horizontal roots are in
the top 40 cm of soil and grow out from the
palm about 4 m.


Jim


Seasonal
growth,
lifespan and
aging

Different parts of trees
grow at different times
of the year, and the
pattern varies by
species and climate
(Figure 13). In one
typical pattern trees
begin with shoot
growth in the spring,
followed by trunk


11

Ii
1


4
*I
,b1


longer in the growing season than older trees.
Length of the active growth is deter-mined by
temperature, daylength and water.

Tree species have a wide range of lifespans.
For example, while peach trees may live only 30
years, oaks may live several hundred years,
cypress 1,600 years, and bristle cone pine up to
5,000 years in an undisturbed site in the forest
(Kramer and Kozlowski 1979). It may be very
stressful for several forest tree species when you
plant them in the city. The average tree in the
downtown lives only 13 years, one tenth the
lifespan of a tree at a
j r rural site (Figure 14).


Dowatown Residential Bet City Rural Site
Site
Planting site
Figure 14. The average tree lives only 13 years in the city, one
tenth as long as a tree at a rural location (American Forests
1992).


What happens to trees
as they age? Some of
the likely occurrences
are the following: (1)
Growth slows down,
(2) Trees are more
susceptible to diseases
and insects, (3) The
tops of the trees are
more likely to die
back, (4) Wounds heal
more slowly, (5) There
are fewer numbers of
leaves relative to the


Spring Summer Fall


t



S37
1
: : .


Winter


,I







size of the tree, and (6) There is an increased
number of dead branches. All of these
characteristics can also be seen in urban trees as
they begin to die and/or show signs of poor
health.


Growth and tree form

The apical bud is the bud at the tip of a stem;
lateral buds are on the sides of the branches.
Apical dominance means that the apical bud at
the tip of the stem controls the other
buds and inhibits the growth of these
buds. Of course most palms only have
one apical bud. Therefore palms
usually grow straight with no
branching (Figure 15a); they are an
extreme example of apical dominance.
Pines exhibit a little less apical
dominance (Figure 15b). The main
stem is still prominent, but branches
formed by lateral buds change the
form exhibiting less apical dominance
than palms. An oak tree has very little
apical dominance with several branches
dominating the crown (Figure 15c).
And this illustrates how growth habits
can change the form of a tree.



Some examples of the
urban environment influencing
growth

Urban trees are subjected to a tremendous
amount of stress. Soils are compacted, trees are
over- or incorrectly-pruned, roots are given very
little space to grow, trees are improperly staked,
and on and on. A few of the stress-induced
practices and environmental conditions are
discussed briefly along with how they affect
growth.

Pruning: What happens when you prune a tree?
If you prune the apical buds, the lateral buds are
released and new shoots grow. If you prune


older, large diameter stems, two things may
happen: (1) Dormant buds, that were produced
long ago during primary growth, can grow into
new branches, and (2) New meristems arise and
produce new buds and shoots. This growth of
new branches is most likely to occur in
angiosperms -- everyone has seen sprouts from
the stump of a freshly cut oak, maple, or elm.
Pine trees however do not have these dormant
buds and will not sprout. Of course, if you
remove the apical bud from a palm, it will die --
remember most palms only have one bud at the
top of the tree.


Figure 15. Growth habits change the form of trees:
(a) Palms have one bud, a dominant stem and no
branches, (b) Pines, branches with less stem
dominance, and (c) Oaks, a rounded form with
little apical dominance.







size of the tree, and (6) There is an increased
number of dead branches. All of these
characteristics can also be seen in urban trees as
they begin to die and/or show signs of poor
health.


Growth and tree form

The apical bud is the bud at the tip of a stem;
lateral buds are on the sides of the branches.
Apical dominance means that the apical bud at
the tip of the stem controls the other
buds and inhibits the growth of these
buds. Of course most palms only have
one apical bud. Therefore palms
usually grow straight with no
branching (Figure 15a); they are an
extreme example of apical dominance.
Pines exhibit a little less apical
dominance (Figure 15b). The main
stem is still prominent, but branches
formed by lateral buds change the
form exhibiting less apical dominance
than palms. An oak tree has very little
apical dominance with several branches
dominating the crown (Figure 15c).
And this illustrates how growth habits
can change the form of a tree.



Some examples of the
urban environment influencing
growth

Urban trees are subjected to a tremendous
amount of stress. Soils are compacted, trees are
over- or incorrectly-pruned, roots are given very
little space to grow, trees are improperly staked,
and on and on. A few of the stress-induced
practices and environmental conditions are
discussed briefly along with how they affect
growth.

Pruning: What happens when you prune a tree?
If you prune the apical buds, the lateral buds are
released and new shoots grow. If you prune


older, large diameter stems, two things may
happen: (1) Dormant buds, that were produced
long ago during primary growth, can grow into
new branches, and (2) New meristems arise and
produce new buds and shoots. This growth of
new branches is most likely to occur in
angiosperms -- everyone has seen sprouts from
the stump of a freshly cut oak, maple, or elm.
Pine trees however do not have these dormant
buds and will not sprout. Of course, if you
remove the apical bud from a palm, it will die --
remember most palms only have one bud at the
top of the tree.


Figure 15. Growth habits change the form of trees:
(a) Palms have one bud, a dominant stem and no
branches, (b) Pines, branches with less stem
dominance, and (c) Oaks, a rounded form with
little apical dominance.







Staking:
How does
staking affect
growth?
Sometimes
when small
trees are
planted
people think
that it is
necessary to
stake them.
However,
studies have
shown that
trees that are
allowed to
sway in the
wind are
sturdier. Figure 16. Staked trees tend to be less
Staked trees stable and sometimes tend to topple
tend to be when the stakes are removed and the
less stable tree is exposed to wind.
and
sometimes topple when stakes are removed and
trees are exposed to wind (Figure 16). This can
be explained by looking at growth differences.
When trees blow in the wind there is a
redistribution of the amount and nature of
diameter growth on the leeward and windward
sides of the tree trunk. "Reaction wood" is
formed, and this wood has larger and thicker
walled cells than other wood. Hence when
exposed to wind a tree becomes sturdier and can
tolerate wind better. For this reason, do not
stake young trees unless they absolutely will not
stand up without a stake. Remember palms do
not have cambial (diameter) growth, so staking
palms is okay and often necessary until new
roots stabilize the palm in the landscape.

Compacting the soil: Soil conditions in urban
plantings are often ignored, but this is often the
cause of many tree health problems. Trees often
have limited rooting space and are similar to
large potted plants. Soil compaction can occur
due to such things as construction equipment,
sidewalks and streets, and footsteps. What
happens to growth when tree roots are in
compacted soil? A study of Monterey pine


seedlings showed that trees grown in highly
compacted soil had less root volume and weight
-- roots didn't grow as well in compacted soil
(Table 1). This translated into reduced shoot
growth -- trees were shorter and had less weight
when the soil was compacted. This happens in
the city too -- roots can't grow, water can't
permeate into


Table 1. Soil compaction can negatively effect root and shoot
growth; Monterey pine seedlings had poorer growth in this
study (from Sands and Bowen 1978).

Soil Dry Weight Root Volume Heiht
Bulk (g) (cmF) (cm)
Density Shoots Roots
(g cmP)

1.60 3.6 3.0 24.7 20.5
1.48 5.9 4.9 39.3 29.2
135 7.0 5.6 47.3 32.8

*High bulk density means high soil compaction.


the soil, nutrient uptake is reduced, and the
result is poorer tree growth. Of course, the
ultimate effect is poor tree health and death.
Some ways to avoid compaction are: (1)
incorporate organic matter into the soil, (2)
prevent vehicles from operating beneath the
canopy, and (3) when construction traffic must
work around trees make sure it is when the
soils are dry (wet soils are more easily
compacted) or spread a thick layer of coarse
mulch beneath the canopy.

Conclusions

Trees grow in response to their environment
and their genetic make-up. Environmental
factors such as high temperature or soil
compaction can influence physiological
processes such as photosynthesis and in turn
impact growth. Meristems are the areas
within the tree where growth occurs. Most
trees grow in shoot height and diameter and
root length and diameter. Palms, however,
have only one growing tip and do not grow in







diameter. A tree's form is controlled by
branch orientation and by the amount of apical
dominance. Altering the environment or
management practices to decrease stress, and
selecting the right tree for the right place will
promote growth and longevity.

And finally, as the tree ages and grows, does
the birdhouse move up the tree and out of
your reach? No! Why not? Remember a
tree only grows in height at the apical
meristems at the tips of branches. At the
height of the bird-house only trunk diameter
growth is occurring.



References

Kramer, P.J. and T.T. Kozlowski. 1979.
Physiology of woody plants. Academic Press,
New York. 811 p.

Moll, G. 1992. Trees in the red. Urban
Forests. American Forests. Washington D.C.
February/March. p. 10.

Sands, R. and G.D. Bowen. 1978.
Compaction of sandy soils in radiata pine
forests. II. Effects of compaction on root
configuration and growth of radiata pine
seedlings. Aust. For. Res. 8:163-170.


For more reading about tree
growth

Bell, A.D. 1991. Plant Form: An Illustrated
Guide to Flowering Plant Morphology. Oxford
University Press. New York. 341 p.

Corner, E.J.H. The Natural History of Palms.
1966. University of California Press.
Berkeley. 393 p.

Fahn, A. 1991. Plant Anatomy. Fourth
edition. Pergamon Press. Oxford. 588 p.


Harltey, C.W.S. 1977. The Oil Palm (Elaeis
guineensis Jacq.). Second edition. Longman.
London. 806 p.

Harris, R.W. 1992. Integrated Management of
Landscape Trees, Shrubs, and Vines. 2nd
edition. Prentice-Hall. New Jersey. 674 p.

Kozlowski, T.T. 1971. Growth and
Development of Trees. Vol.I. Academic
Press. New York. 443 p.

Kozlowski, T.T., P.J. Kramer and S.G.
Pallardy. 1991. The Physiological Ecology of
Woody Plants. Academic Press. New York.
657 p.

Eaetsch, W.M. 1979. Plants Basic Concepts
in Botany. Little, Brown and Company.
Boston. 510 p.

Mosbrugger, V. 1990. The. Tree Habit in
Land Plants. In Lecture Notes in Earth
Sciences, Vol. 28. Edited by S. Bhattacharji,
G.M. Friedman, H.J. Neugebauer and A.
Seilacher. Springer-Verlag. Berlin. 161 p.

Uhl, N.W. and J.Dransfield. 1987. Genera
Palmarum. A Classification of Palms Based on
the Work of Harold E. Moore, Jr. Allen
Press, Lawrence, Kansas. 610 p.

Wilson, B.F. The Growing Tree. 1984. The
University of Massachusetts Press. Amherst.
138 p.



Acknowledgments

We are very grateful for the constructive and
thorough reviews of this publication made by
Ed Gilman, Bill Hubbard, Bira Malavasi and
Tim White. Additional thanks go to Bira
Malavasi for the informative drawings of tree
growth used in this publication.







diameter. A tree's form is controlled by
branch orientation and by the amount of apical
dominance. Altering the environment or
management practices to decrease stress, and
selecting the right tree for the right place will
promote growth and longevity.

And finally, as the tree ages and grows, does
the birdhouse move up the tree and out of
your reach? No! Why not? Remember a
tree only grows in height at the apical
meristems at the tips of branches. At the
height of the bird-house only trunk diameter
growth is occurring.



References

Kramer, P.J. and T.T. Kozlowski. 1979.
Physiology of woody plants. Academic Press,
New York. 811 p.

Moll, G. 1992. Trees in the red. Urban
Forests. American Forests. Washington D.C.
February/March. p. 10.

Sands, R. and G.D. Bowen. 1978.
Compaction of sandy soils in radiata pine
forests. II. Effects of compaction on root
configuration and growth of radiata pine
seedlings. Aust. For. Res. 8:163-170.


For more reading about tree
growth

Bell, A.D. 1991. Plant Form: An Illustrated
Guide to Flowering Plant Morphology. Oxford
University Press. New York. 341 p.

Corner, E.J.H. The Natural History of Palms.
1966. University of California Press.
Berkeley. 393 p.

Fahn, A. 1991. Plant Anatomy. Fourth
edition. Pergamon Press. Oxford. 588 p.


Harltey, C.W.S. 1977. The Oil Palm (Elaeis
guineensis Jacq.). Second edition. Longman.
London. 806 p.

Harris, R.W. 1992. Integrated Management of
Landscape Trees, Shrubs, and Vines. 2nd
edition. Prentice-Hall. New Jersey. 674 p.

Kozlowski, T.T. 1971. Growth and
Development of Trees. Vol.I. Academic
Press. New York. 443 p.

Kozlowski, T.T., P.J. Kramer and S.G.
Pallardy. 1991. The Physiological Ecology of
Woody Plants. Academic Press. New York.
657 p.

Eaetsch, W.M. 1979. Plants Basic Concepts
in Botany. Little, Brown and Company.
Boston. 510 p.

Mosbrugger, V. 1990. The. Tree Habit in
Land Plants. In Lecture Notes in Earth
Sciences, Vol. 28. Edited by S. Bhattacharji,
G.M. Friedman, H.J. Neugebauer and A.
Seilacher. Springer-Verlag. Berlin. 161 p.

Uhl, N.W. and J.Dransfield. 1987. Genera
Palmarum. A Classification of Palms Based on
the Work of Harold E. Moore, Jr. Allen
Press, Lawrence, Kansas. 610 p.

Wilson, B.F. The Growing Tree. 1984. The
University of Massachusetts Press. Amherst.
138 p.



Acknowledgments

We are very grateful for the constructive and
thorough reviews of this publication made by
Ed Gilman, Bill Hubbard, Bira Malavasi and
Tim White. Additional thanks go to Bira
Malavasi for the informative drawings of tree
growth used in this publication.







diameter. A tree's form is controlled by
branch orientation and by the amount of apical
dominance. Altering the environment or
management practices to decrease stress, and
selecting the right tree for the right place will
promote growth and longevity.

And finally, as the tree ages and grows, does
the birdhouse move up the tree and out of
your reach? No! Why not? Remember a
tree only grows in height at the apical
meristems at the tips of branches. At the
height of the bird-house only trunk diameter
growth is occurring.



References

Kramer, P.J. and T.T. Kozlowski. 1979.
Physiology of woody plants. Academic Press,
New York. 811 p.

Moll, G. 1992. Trees in the red. Urban
Forests. American Forests. Washington D.C.
February/March. p. 10.

Sands, R. and G.D. Bowen. 1978.
Compaction of sandy soils in radiata pine
forests. II. Effects of compaction on root
configuration and growth of radiata pine
seedlings. Aust. For. Res. 8:163-170.


For more reading about tree
growth

Bell, A.D. 1991. Plant Form: An Illustrated
Guide to Flowering Plant Morphology. Oxford
University Press. New York. 341 p.

Corner, E.J.H. The Natural History of Palms.
1966. University of California Press.
Berkeley. 393 p.

Fahn, A. 1991. Plant Anatomy. Fourth
edition. Pergamon Press. Oxford. 588 p.


Harltey, C.W.S. 1977. The Oil Palm (Elaeis
guineensis Jacq.). Second edition. Longman.
London. 806 p.

Harris, R.W. 1992. Integrated Management of
Landscape Trees, Shrubs, and Vines. 2nd
edition. Prentice-Hall. New Jersey. 674 p.

Kozlowski, T.T. 1971. Growth and
Development of Trees. Vol.I. Academic
Press. New York. 443 p.

Kozlowski, T.T., P.J. Kramer and S.G.
Pallardy. 1991. The Physiological Ecology of
Woody Plants. Academic Press. New York.
657 p.

Eaetsch, W.M. 1979. Plants Basic Concepts
in Botany. Little, Brown and Company.
Boston. 510 p.

Mosbrugger, V. 1990. The. Tree Habit in
Land Plants. In Lecture Notes in Earth
Sciences, Vol. 28. Edited by S. Bhattacharji,
G.M. Friedman, H.J. Neugebauer and A.
Seilacher. Springer-Verlag. Berlin. 161 p.

Uhl, N.W. and J.Dransfield. 1987. Genera
Palmarum. A Classification of Palms Based on
the Work of Harold E. Moore, Jr. Allen
Press, Lawrence, Kansas. 610 p.

Wilson, B.F. The Growing Tree. 1984. The
University of Massachusetts Press. Amherst.
138 p.



Acknowledgments

We are very grateful for the constructive and
thorough reviews of this publication made by
Ed Gilman, Bill Hubbard, Bira Malavasi and
Tim White. Additional thanks go to Bira
Malavasi for the informative drawings of tree
growth used in this publication.



































































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