SS9301-CS 920221 L-1683
. Texas Agricultural Extension Service
EVALUATION OF--TEXAS SHADE TREES
Alan D, Dreesen*
Interest in the value and function,of shade trees has Size
grown in recent years. These trees perform several The shade tree evaluation committee of the Inter-
environmental functions and damage to them causes national Society of Arborieulture determined that the
a monetary loss by the owner. The first formula for size of a tree's trunk expresses shade tree size. Thc
determining a dollar value of shade trees was American Association of Nurserymcn's approach in
presented to the Xational Shade Tree Conference measuring tree diameter is generally followed. For
(now International Society of Arboriculture) ~ 1949. trees with a 'diameter 4-inches or gmaller, the
Since then, several revisions have made the formula · diameter is determined at a height of 6 inches above
more acceptabl~to insurance companies, courts and the ~round. For trees with a diameter of 5 to 8 in-
the Internal Revenue Service (IRS). ehes. the diameter i~ determined 12 inches above the
When using the formula to arrive at'a value an- ~roun~. For trees with diameters larger than S inches.
ticipated as a casualty loss. be aware that losses as of thc diameter is determined at height (4.5 feet~. Ex-
January 1. 1983 for non-business taxpayers must ex- ceptions to these rules occur where low branches cause
ceed 10 percent of the adjusted gross income in the trunk sx~ell, in which case an evaluator would
year of the loss. Therefore one may need a substan- measure the diameter just above the swollen area. For
tial loss to qualify. For more information on casual- multi-trunked trees, full diameter of the largest trunk
tv losses, see fact sheet I.-1516. Dama? R~overv plus half the diameter of thc other trunks determines
Opl)ortunities' for I, oss of Landscape Tr(~s. the diameter for computing the cross section area
which is the number used for the size factor in the
Replacement Value formula ~figurc 11. The cross section area is deter-
The value of shade trees in Texas usually can be mined by the formula ().7854D: where D e(luals the
determined by the fair market value tplanted and diameter measured. The current basic value of a
~uaranteed~ f~om tree nurseries. If a species is not t)erfect Sl')ecimen shade tree. in the comn~ittee's ol)in-
available from a nursery and the tree i~ small, base ion. is 825 l~er ,(luare inch of trunk cross ~ec'tim~. For
the fair market value on that afa similar species of example, a IO-inch Clas, I tree in perfect condition
c(,mparable size. l,arge tree companies sell and plant aud Io(:ati(m would !)~. x~rth 81.0(54 ~at 825
,t'x cra[ species -f trees up to ~ ineht"~ in diameter. The ,~ i,~arc inch'.
value t~f lar?r trees can be estimated usi;u2 the 11.7~5-tl): =(!.7$34 10~z= 7~.54 iw
f~)rmula. The formula u>uallv underestimates the 7b.5.t inz x ~825. in:. = 81.964
value of small trees.
Species
The Formula Not all species and varieties of trees are of equal
Four factors are considered in the formula: siie: _.. i:iI~e.:Termanence, maintenance n~ds. landscape
species, condition and location. ; Yi/fih~:2nd site adaptability influence the value of
...... ~ ~g2 ~rouPing tree speei~ into value classes is
Size X N X q)ecies class X condition X location = value
subjective and may vary from one part of the state
N = ISA value per in: of cross sectional area and one tree specialist to another. The following list
can guide the appraiser Who must also judge based
on experience with the species. Species value of trees
not listed should be made by the specialist invoh'ed
'Extension forester. The lexas AiM University Syslem. 'in the evaluation.
Texas Agncoltaral Extens,on Serv,ce · Zerle L. Carpenter. Director · The Texas A&M Umversity System * College Station. Texas
I
SIZE
To determine the diameter of a tree, measure a small tree (4 inches in diameter or
less) at 6 inches above the ground, a medium-sized tree (5 to 8 inches in diameter)
at 12 inches above the ground and a large tree (larger than 8 inches) at 41/2 feet above
the ground. Use sound judgment on measuring odd shaped trees. In measuring multi-
trunk trees, measure the diameter of the largest trunk and add half the diameter of
the other trunks,
~_~ ........ ..~ 41/2 feet
At narrow
....... ~1.2 inches -- --- portion
..... 6 inches !i /
..
Up to and 5 to 8 inches More than 8 inches Awkward swell
including 4 inches
Figure I
Class ltl00 percent Class 2m80 percent
Carya spp.--Hickorics Acer grandidentatum sinuosum--Bigtooth Maple
Carya illinoensis--Pecan Arbutus texana--Texas Madrone
Cornus florida--Flowering Dog, rood Ehretia anacua--Anaqua
Diospyros texana--Texas Persimmon Fraxinus velutina (Select Male)--Velvet Ash
Fagus grandifolia--American Beech Fraxinus velutina 'glabra'--Modesto Ash
Ilex opaca--American Holly Ginkgo biloba--Ginkgo
Ilex comitoria--Yaupon ttolly GTmnocladus dioicus--Kentucky Coffeetree
]uglans nigra--Black Walnut Koelreuteria bipinnata--Southern Golden Raintree
Liq~,idambar strqraciflua--Sweetgum Koelreuteria paniculata--Panicled Golden Raintree
Magnolia grandiflora--Southern Magnolia Lagerstroemia indica--Crepemyrtle ~
.'~la~nolia t'ir~iniana--Sweetbay Liriodendron tulipifera--Tulip-poplar
N!/s~a sqh'atica--Tupclo Olea rnanzanilla--Manzanilla Olive
t'icc~ lmn~ens--Col(~rado Blue Spruce Pinus elliottii--Slash Pine
Finus edulis--Pifi(,n Pi,~c Pinus halepensis--Aleppo Pine
Pim,s ponderosa--Ponderosa Pine Pinus nigra--Austrian Pine
t'i,,us taeda--Lohlollv Pine Pinus thunbergii--Japanese Black Pine
Pithccellobium flexicaule---Tcxas Ebony Pistacia chinensis--Chinese Pistachio
Qm'rcus alba--White Oak Pyrus calleryana--Callery Pear Cultivars
Om'mss falcata--Southern Red Oak Quercus phellos--Willow Oak
Quercus nmcrocarpa--Bur ()ak Quercus stellata--Post Oak
Quercus muhlenber~ii--Chinkapin Oak Quercus velutina--Black Oak
Quercus nigra--Water Oak Sophora japonica--Japanese Pogodatree
Quercus shutr,ardii--Shumard Oak Ulmus americana--American Elm
Qm'rcus texana--Spanish Oak
Qm'rcus rirginiana--Live Oak
So;,hora ~ecundiflora__Mescal Bean Sophora Class 3t60 percent
'f axod.,n distichum--i~aldcvpress Acacia farmesiana--lluisache
['ln,u~ cra.~'~ifolia--Ccdar Eim Acer rubrum--Red :naple
Bvtula ;u~:,'a-- R:vcr Birch Condition
Brou.~-mu'tia pap!lrifera--Paper Mulberry Few shade trees are perfect. As trees become large
Bu,u'llia lanuei~w~a~Gum Elastic and old, they ofter become defective through decay,
Cedru~- th'oda ra~ Deodar Cedar broken limbs, damage by humans or uneven growth.
Ccitt., ,~ccuh, ntalis~Common tlackberrv The specialist appraising the tree must judge the con-
('cvcis canadeusi,s~Redbud dition on a percentage b~is. For example, a 10-inch
(']u!w,,t~ hm'arts~l)csert Willow tree in Cla~ I might be poorly proportioned or
('uin'c, ~u ~ ar~zon Wa ~Arizona C~ press dgplay symptoms of heart rot. Instead of being worth
Eriob~,trqa japonica~ l,oquat $1,9~, it would ~ appraLs~ at ~ ~r~nt or $1,178.
Fraxinus pt'nnsy[t'anictt lanceo&ta~Green Ash A knowledge of tree patholo~', entomolo~' and
Fraxinus cclutina . ~eedlin~ ~Arizona Ash physioloD' is impo~ant to prof~sional evaluation. In
(;b,ditvUi triacanthos ine~nis~Thornless some situations consulting a diagnostician before
I ionevlocust d~iding a tree's condition percentage makes the
]uniperus spp.~Junipers. Cedar evaluator more confident. As a guide, the following
l~,ucaena pulrerulenta~Great Lead-tree system can help a trained arborist. There are six con-
Malus ~pecies and t'arieties~Flowering Crab Apples dition factors, A through F, each rating from one to
,~loru~ alba ~fruitless~Fruitless Mulberry five. The sum of the rating for each of the six factors
Per,va amerwana~Avocado is the tree's condition rating. The percent based on
Per.sea borbonia~Redbav this rating is used in the formula.
Pinus cchinata~Shortleaf Pine
Pinus pinea~Italian Stone Pine
Platanus occidentalis~American Planetrees, A. Trunk condition Rating
Sycamore Sound and solid 5
Prosopis glandulosa~Honey Mesquite Missing section of bark 3
Prunus mexicana~Mexican Plum Extensive decay 1
Sabium sebiferum~Chinese Tallow
Sapindus drummondii~Vestern Soapberry
Ulmus parvifolia~Chinese Elm B. Growth (varies with species)
Ulmus parvifolia sempervirens~Evergreen Elm Vigorous 3
Moderate 2
Poor
Class 4--40 percent C. Structure
Acer negundo--Boxelder Sound 5
Acer saccharinum--Silver Maple One major or .several minor limbs dead, 3
Ailanthus altissima--Tree of Heaven broken or missing
Albiziajulibrissin--Silktree Two or more major limbs dead, broken 1
Catalpa spp.--Catalpa or missing
Celtis laevigata--Sugarberr?'
Crataegus spp.--Hawthorns D. Insect and disease
Eleagnus angustifolius--Russian Olive No pests 3
Firmiana simplex--Chinese Parasol Tree One pest 2
Maclura pomifera--Bois d'Arc Two or more pests 1
Melia azedarach~Chinaberry
Morus rubra--Red Mulber~'
Parkinsonia aculeata~Palo Verde E. Crown development
Populus spp.--Cottonwood and Poplars Full and balanced 5
Prunus blireiana~Ornamental Plum Full but unbalanced 3
Robinia pseudoacacia~Biack Locust Unbalanced and lacking a full crown 1
Salix spp .~Willows
Tamarix spp.--Tamarisk
Thuja spp.~Arborvitae F. Life expectancy (at time of evaluation)
Ulraus pumila--Siberian Elm More than 30 years 5
Ziyphus jujube--Jujube Fifteen to 20 years 3
Less than 5 years 1
Total point rating Percentage to
(A + B + C + D + E + F) use in formula LOCATION
26-'23 80-100
22-19 60- 80 STREET
18-14 40- 60 ,~
13-10 20- 40
9-6 0-20
Only an experienced evaluator can make accurate
condition determinations.
Location
Location determines the value of a tree in the land- A patio tree has
scape (figure 2). An understanding of the specific a greater Ioca-
tree's role helps when applying this factor to the for- tion value than a
mula. The following conditions are outlined for,mfidanc'e: ~].P ATIO Ithat harmonytree that is out Oflandscape mayWith t~ethe or a
Feature or historical trees ............ 90-100 c~ traffic hazard.
Average residential, landscape trees ... 80- 90 c~,
Malls or shoppimt center trees ........ 75- 85,~
Public and commercial area trees ..... 70- 80% Figure 2
Arboretum and park trees ........... 60- 80%
Golf course trees, strategically located. 60- 80 %
Street and bonlevard trees ........... 60- 80c? shade tree evaluation outlined here may apply to
Screen and windbreak trees .......... 60- 70 c;. casualty losses. Replacement costs may be acceptable
Recreational and picnic area trees .... 60- 70 c~ as proof of property value reduction. To back up tree
lndnstrial area trees ................ 50- 70% casualty loss claims, use IRS rulings on similar tree
Out-of-city highway trees ........... 40- 60"~ and shrub losses. The attitude of regional reviewing
Native. open woods trees ............ 30- 40 c; officials toward the legal standing or value of shade
trees also may determine the extent of a casualty loss.
The Tax Equity and Fiscal Responsibility Act of 1982
For example, if a 15-inch l. ive Oak of good form. states that personal casualty losses are claimable on-
without diseases, shades a picnic area in a city park Ix' to the extent that they exceed 10 percent of the tax-
in Ceutral Texas and is vandalized with an axe. how payer's adjusted gross income for the year of occur-
is the monetary damage determined, assuming the renee. There is still a S100 exclusion. The Tax Reform
trec has no chance of survival? The formula: Act of 1986 did not change casualty loss treatment.
Size x S25 x class x condition x location = value The formula for shade tree evaluation cannot deter-
0.7854 (15~) x (S25) x (800/0) x (100°.0) x (80%) = S2.827.44 mine the value of fruit or nut bearing trees, which
can be appropriately determined by crop yield.
Only a profesq,.:na! tree :,l)ccialist ~h,;uld ~-v,duatc Neither is it intended for evaluation of pah,'.' trees.
,bade tree, for ir~-,.i;'ii.!l..'c comlm:m:- ~r c~',m'..'-. 'l'ht- :,ince palms do not expand in diametc, r. I-'air markct
IRS ,qs~roac.hc~ trot. al~prai>a! di!'f,..rcntlx..\nv..-a:':a!- x ulue {~r a dollar val'..~e per foot of height .~rowth
tx h,,.q claim m,t>t uic-i,,&-i:r-ot' that thc valm. ,:.,f !he detcrBiirlt.,, thc u c, rth of palm trees. Cht~c.k with loci'il
pro?.rt? w,i, rt-d~wcd b'-, ti',~ ,a;..'ic. am(,,mt ;ts that nurscric, that sell them to determine the x'altw :~f a
ch, in',vd. ['qi!i~ ¢t~la~il:,.:d a'.,~?raist-r.,., i>rim, iplt.s ,~t' particular specie.~ of pahn.
Educational programs conducted by the Texas Agricultural Extension Service serve people of all ages regardless of socioeconomic
level, race. color, sex. religion, handicap or national origin.
Issued in furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of Congress of May 8, 1914, as amended,
and June 30. 1914. m cooperation w~th the United States Department of Agriculture. Zerle L. Carpenter, Director, Texas Agricultural
Extension Service, The Texas A&M University System.
5M--6-87. Rews~on FOR