Comparative decay resistance of heartwood of different native species when used under conditions that favor decay

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Material Information

Title:
Comparative decay resistance of heartwood of different native species when used under conditions that favor decay
Series Title:
Report ;
Physical Description:
2 leaves : ; 26 cm.
Language:
English
Creator:
Hunt, George M ( George McMonies ), b. 1884
Forest Products Laboratory (U.S.)
University of Wisconsin
Publisher:
United States Dept. of Agriculture, Forest Service, Forest Products Laboratory
Place of Publication:
Madison, Wis
Publication Date:
Edition:
Rev.

Subjects

Subjects / Keywords:
Heartwood -- Deterioration   ( lcsh )
Heartwood -- Microbiology   ( lcsh )
Genre:
federal government publication   ( marcgt )
non-fiction   ( marcgt )

Notes

Statement of Responsibility:
by Geo. M. Hunt.
General Note:
Cover title.
General Note:
"Revised June, 1931."
General Note:
"In cooperation with the University of Wisconsin."

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029615259
oclc - 758359778
System ID:
AA00020750:00001

Full Text




U. S. Department of Agriculture, Forest Service

FOREST PRODUCTS LABORATORY

In cooperation with the University of Wisco-nsin

MADISON, WISCONSIN












COMPARATIVE DECAY RESISTANCE OF HEARTWOOD

OF DIFFERENT NATIVE SPECIES WHEN USED

UNDER CONDITIONS THAT FAVOR DECAY

By GEO. M. HUNT
In Charge, Section of Wood Preservation


















Revised
June, 1931














Digitized by the Internet Archive
in 2013









http://archive.org/details/decay00fore







C .,MPA.TIVE DECAY RESISTANCE OF HEAR--"7cD OF OIFFW32 S

I:AT:-.' SCIES ,,:.:: U:_D UNDER CO" ITIONS -HAT FAVOR DrCAY


Wood kept constantly dry or continuously su.:.r.cr-ed
in water does not decay, regardless of sapwood or speci, lar_ ; roportion of the wood in use is kept so dry at all
times that it lasts indefinitely. moisture e and temperature.
,re the principal factors that affect the rate of decay; they
vary greatly ith the local conditions surrounding the wood
in service.- -hen exposlI to conditions that decay,
wood in w:;rs; humid areas of the United States d,:,3 more
rapidly than in cool or dry areas. High altitudes .re as a
rule less favorable to decay than low because the average
temperatures are lower and the growing seasons for fungi are
shorter.

The natural decay resistance of all common native
species of wood is in the heartwood. Then untreated, the
sapwood of practically all species has low decay resistance
and generally short life under decay-producing conditions.
The decay resistance, or durability, of heartwood in service
is greatly influenced by differences in the character of
the wood, the attacking fu.-gas and the conditions of expo-
sure. Therefore a widely different length of life y -.
obtained from pieces of wood that are cut from the ;" e
species or even the same tree and used under apparently sim-
ilar conditions.

General comparisons of the relative decay resist-
ance of different species must be estimates. They can not
be exact and they :rny be very misleading if under rstood as
math ..-itically accurate and applicable to all cases. They
may be very useful, however, if understood as aproximate
aver',Ies only, from which specific cases :y vary consid-
erably, and .- having application only where the wood is
used under conditions that favor decay. The following
classification of common native species is subject to the
limitations mentioned above.

-A more detailed discussion of the factors that influence
the decay of untreated wood in service is g-iven in a
r..ir:;Ceo- r ph on that subject which may be obtained from
the Forest Products Laboratory, N''idison, '7is.


R800









Fr,-., se' ice re cords where v il:'Ible, ,p l7. e tod I
by -'reneral experience, the heartwo,- of the following pccs-
.r.y .' classed as arable eve:. when use- und conditions
that favor dec-y: The catalp .., practically all of the ced
chestnut, southe'. cypress, the juniper rs, black locust, red
mulberry Osag'e-oranFe, redwoodi, clack walnut, and Paciic yw

Simnilarly the heart-vood of as; n, b --:-.-ood, cotton-
w-.od, td true f'irs (not Dr- -.las fir), an the willo.s wnC
use 1 i:- er conditions thart favor decay may be classed -s
low in decay resistance, while the heartwood of Douglas fir,
red g'm, western larch, chestnut oak, southern yellc.: pin,
.J t:.-,:rack .-..y be classed as intermediate. The he0rt0wood
of e:.: Douglas fir, .oncy locust, white oaK, and denC
southern ine rmay alsoo be classed inter. ediate but nearly
as durable as some of the species na,,ed in the high .ur-
ability groups. Th- heartvwood of the ashes, bCech, the
birches, the h-".locks, sugar :nale, the red oaks, nnd the
spruces *ay 't considered on the border line between the
intermediate and nondurable groups and can not with assur-
ance placed wvholly in either group.


-The species are listed alphabetically and noot in order of
thoi: rel tive durability.


























R8 9 -3-




UNIVERSITY OF FLORIDA
l IIll [ II IN l 111 111111 111
3 1262 08929 1883
























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