This file was created by scanning the printed publication.
Errors identified by the software have been corrected;
however, some errors may remain.
Diseases and Environmental Factors of the
Pinyon-Juniper Communities
D. J. Weber
E. D. Bunderson
J. N. Davis
D. L. Nelson
A. Hreha
Abstract-The pinyon-juniper woodland is the dominant ecosystem in Utah. While it is a very successful ec()system, it is not without
its disease problems. The limiting soil nutrients appear to be
nitrogen, phosphorous, and potassium. Temperature and moisture
gradients are limiting factors in the growth of pinyon and juniper.
Juniper decline appears to be related to drought and temperature stress and increased salts. A number of pathogens occur on
Pinus edulis and Juniperus osteosperma. The most frequent pathogens on junipers are the rust fungi. Mistletoe was more common on
pinyon than juniper but mistletoe infection has an impact on both.
The pinyon-juniper woodland is a widespread vegetation type in the Southwestern United States that is estimated to cover from 40 to 50 million hectares (Allred 1964;
Tausch and Tueller 1990). The pinyon-juniper vegetation
provides a source of fuel, building materials, charcoal, pine
nuts, Christmas trees, and folk medicines (Cronquist and
others 1972; Gallegos 1977; Hurst 1977; Lanner 1975;
Tueller and others 1979). About 80 percent of the acreage is
grazed by livestock and wildlife (Bunderson and others
1986b; Clary 1975). In Utah, this ecosystem is a large
component (62,705 km 2 or 28.6 percent) of the vegetation
(Kuchler 1964). The pinyon-juniper woodlands are valued
for their watershed, aesthetic, and recreational values
(Gifford and Busby 1975). The pinyon-juniper woodlands
also have a range of diseases. They range from non-pa thogen
types (environmental factors) to specific pathogens. Both
types will be discussed in this paper. The purpose of this
manuscript is to review the non-pathogenic factors and
pathogens present in pinyon-juniper woodlands.
In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings:
ecology and management of pinyon-juniper communities within the Interior
West; 1997 Septeinber 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.s.
Department of Agriculture, Forest Service, Rocky Mountain Research
Station.
D. J. Weber is with the Department of Botany and Range Science and
E. D. Bunderson (deceased) was with the Department of Instructional
Science, Brigham Young University, Provo, UT 84602. J. N. Davis and D. L.
Nelson are with the USDA Forest Service, Rocky Mountain Research
Station, Shrub Sciences Laboratory, Provo, UT 84606. A. Hreha is with the
Red Butte Botanical Garden, University of Utah, Salt Lake City, UT 84112.
118
Influence of Environmental
Factors ____________
Soil and Mineral Factors
Soil samples and foliage samples (255 trees) were collected from 17 pinyon-juniper sites throughout Utah (fig. 1,
table 1). Mineral analysis of soils and leaf samples were
determined. The mineral concentration was correlated with
the mineral concentrations of the leaves at the different
sites. Statistical and factorial analyses suggested that the
primary limiting soil nutrients in the native soils were
nitrogen, phosphorous, and potassium. The linear correlation coefficient of foliage mineral composition and soil mineral composition was 0.66 for nitrogen and potassium
and 0.49 for sodium and phosphorous. Rotated orthogonal
Figure 1-Location of the 17 pinyon-juniper study
sites in Utah.
USDA Forest Service Proceedings RMRS-P-9. 1999
Table 1-Specific names of the 17 primary
pinyon-juniper study sites in Utah.
Number
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Site name
Jackson Springs
Tobin Bench
Peters Point
Alkali Ridge
Cyclone Flat
Indian Peak
Ephraim
Manti
Black Mountain
Triangle Mountain
Beaver Ridge
Gordon Creek
Dutch John
Taylor Flat
Rabbit Gulch
Henry Mt (Stevens Narrows)
Henry Mt (Airplane Flat)
Utah, Wyoming, and Washington. The reported pathogens
on Pinus edulis were:
Acanthophysium albida (Gilbertson and others 1974)
Armillaria mellea (Plant Disease Index 1960)
Arceuthobium campylopodum (Peterson 1961)
Arceuthobium divaricatum (Hreha and Weber 1979)
Coleosporium crowellii (Christenson and Peterson 1961)
Coleosporium jonesii (Gilbertson and McHenry 1969)
Coleosporium ribicola (Peterson 1962)
Cronartium occidentale (Plant Disease Index 1960)
Dacryobolus karstenii (Gilbertson and others 1975)
Heterobasidion annosum (Tegethoff 1973)
Leptographium wageneri (Landis and Helburg 1976)
Phellinus pini (Plant Disease Index 1960)
Phoradendronjuniperinum (Hreha and Weber 1979)
Tomentella chlorina (Gilbertson and others 1974)
Verticicladiella sp. (Wagener and Mielke 1961)
Verticicladiella wagenerii (Walters and Walters 1977)
Diseases Reported for Junipers
factors from varimax factor analysis were 0.79 for nitrogen,
0.73 for phosphorous and 0.50 for potassium. Correlation of
factors greater than an absolute value of 0.25 are significant
(Bunderson and others 1986a). Increased concentration of
sodium resulted in decreased growth of junipers which
would indicate that J. osteosperma is a salt-sensitive species. Temperature and moisture gradients were also distinct
growth limiting factors in this ecosystem (Bunderson and
others 1985).
Juniper Decline, a Non-Pathogenic Disease
Juniper decline is common in southwestern Utah. The
characteristic symptom is for the distal foliage to become
chlorotic and die. Mortality progresses along twigs until
whole branches or the entire tFee dies. While juniper decline
was observed in Natural Bridges National Monument and
Needles area of Canyon land National Park, no pathogenic
agent appeared to be responsible for the decline problem.
There did not appear to be any high correlation between
high or low amounts of minerals in the soil. It is suggested
that the juniper decline is a combination of drought and
temperature stress which reduces the water resources. The
increased uptake of salts result in complexing of the iron,
magnesium and calcium to form complex crystals in the
leaves which are characteristic of the decline symptoms
(Weber and others 1995).
Diseases Caused by
Organisms __________
Diseases Reported for Pinyon Pine
The printed literature was searched by computer and
manual searches of several western disease herbariums
were done. The States covered by the herbarium searches
were Arizona, Colorado, Idaho, Nevada, New Mexico, Oregon,
USDA Forest Service Proceedings RMRS-P-9. 1999
The reported pathogens on Juniperus osteosperma (Utah
Juniper) were:
Antrodia ferox (Hawksworth 1950)
Daedaleajuniperina (Gilbertson 1975)
Diplomitoporus rimosus (Hedgecock 1912)
Fomesjuniperinus (Bethel 1918)
Gymnosporangium harknessianum (Plant Disease
Index 1960)
Gymnosporangium inconspicuum (Bethel 1918)
Gymnosporangiumjuvenescens (Goodding 1919)
Gymnosporangium kernianum (Bethel 1918)
Gymnosporangium multiporum (Bethel 1918)
Gymnosporangium nelsonii (Bailey 1970)
Gymnosporangium speciosum (Bethel 1918)
Poria rimosa (Gill 1941)
Pyrofomes (Fomes) demidoffii (Gilbertson 1974)
Trametes sepium (Hawksworth 1950)
Uredo phoradendri (Hawksworth 1952)
Correlation of Diseases and
Environment
Pathogens and Physiological Diseases
The diseases present on J. osteosperma was determined
on 17 sites in Utah (fig. 1). The most frequent pathogen on
the research sites was Gymnosporangium (rust fungi).
Gymnosporangium inconspicuum was the most common
rust fungus followed in frequency and severity by G. nelsonii,
G. kernianum and G. speciosum. Mold-mildew type of diseases were correlated with high summer temperature and
fall precipitation. Wood rot was common and correlated
with low winter temperatures and low soil nitrate. Needle
blight, shoot dieback, and needle cast symptoms were common and considered abiotic in origin. Needle blight was
correlated with higher soil salinity. Mistletoe, Phoradendron
juniperinum was present in seven sites (Bunderson and
others 1986b).
119
Table 2-Percent infection comparing pinyon
and juniper on rim, forest, and burned
areas of the south rim of the Grand
Canyon.
Pinyon
Juniper
Rim
Forest
32.3
46.8
30.6
31.8
Burned
0.02
0.02
Mistletoe on Pinyon and Juniper
The distribution and effects of mistletoes on the pinyonjuniper vegetation along the south rim ofthe Grand Canyon
was determined (Hreha and Weber 1979). Arceuthobium
diuaricatum, which infects Pinus edulis, is spread by a
forced ejection mechanism of the mistletoe. Juniperus osteosperma is infected by Phoradendronjuniperinum, which
is spread by birds. Fire was the most effective factor in
limiting the spread of the mistletoes. The trees that had
regrown in the burned areas were the only areas devoid of
mistletoe infection (table 2). The incident of infection increases as trunk diameter and height increases in both
pinyon and juniper (Hreha and Weber 1979).
While in some cases, the non-pathogenic factors and the
pathogens cause death of the trees, no control measures are
used. On the other hand, the replacement seedlings appear
to be more than adequate to replace lost trees.
References ---------------------------------Allred, B. W. 1964. Problems and opportunities on U.S. grasslands.
American Hereford Journal. 54: 70-72.
Author not listed. 1960. Index of Plant Diseases in the United
States. U.S. Dept. Agric. Handbook. No. 165. Washington, DC.
531 p.
Bailey, H. E. 1970. Gymnosporangium nelsonii Arth. on Junipe1'lls
osteosperma (Torr.) Little. U. Calif., Berkeley Herb. No. 1450623.
Bethel, E. 1918. Fomesjuniperinus (Schrenk) Sacco & Syd. in Sacco
on Juniperus osteosperma (Torr.) Little. Rocky Mtn. For. & Ran.
(Colo.) Herb. No. 4242-G.
Bethel, E. 1918. Gymnosporangium inconspicuum Kern on Juniperus osteosperma (Torr.) Little. Rocky Mtn. For. & Ran. (Colo.)
Herb. No. 4851-P.
Bethel, E. 1918. Gymnosporangium Iwrnianum Bethel on Juniperus osteosperma (Torr.) Little. Shrub Sciences Laboratory, Provo,
UT. Herb. No. 186.
Bethel, E. 1918. Gymnosporangium multiporum Kern on Juniperus osteosperl1la (Torr.) Little. Shrub Sciences Laboratory, Provo,
UT. Herb. No. 220.
Bethel, E. 1918. Gymnosporangiul1l speciosum Peck on Juniperus
osteosperma (Torr.) Little. Rocky Mtn. For. & Ran. (Colo.) Herb.
No. 4358-P.
Bunderson, E. D.; Weber, D. J. 1986a. Foliar nutrient composition
ofJuniperus osteosperma and environmental interactions. Forest
Science. 32: 149-156.
Bunderson, E. D.; Weber, D. J.; Nelson, D. L. 1986b. Diseases
associated with Juniperus osteosperma and a model for predicting their occurrence with environmental site factors. Great Basin
Naturalist. 46: 427-440.
Bunderson, E. D.; Weber, D. J.; Davis, J. N. 1985. Soil mineral
composition and nutrient uptake in Juniperus osteosperma in 17
Utah sites. Soil Science. 139: 139-148.
Christenson, J. A.; Peterson, R. S. 1961. Coleosporium c/'Owellii
Cummins on Pinus edulis Engelm. Shrub Sciences Laboratory,
Provo, UT. Herb. No. 979.
Clary, W. P. 1975. Present and future multiple-use demands on
the pinyon-juniper type. In: The pinyon-juniper ecosystem: A
symposium. Utah Agri. Exper. Station. 194 p.
Cronquist, A.; Holmgren, A. H.; Holmgren, N. H.; Reveal, J. L. 1972.
Intermountain flora. vol. 1. New York Botanical Garden, New
York: Hafner Publishing.
120
Gallegos, R. R. 1977. Forest Practices needed for the pinyon-juniper
type. In: Ecology, uses and management of pinyon-juniper
woodlands. USDA Forest Service General Technical Report
RM-39. 48 p.
Gifford, G. F.; Busby, F. E., eds. 1975. The pinyon-juniper ecosystem: A symposium Utah Agriculture Experiment Station. 194 p.
Gil, A. 1941. Poria rimosa (Murr.) on Juniperus osteosperma
(Torr.) Little. Univ Ariz. Herb. No. 10601.
Gilbertson, R. L. 1975. Daedalea juniperina (Murr.) Murr. on
Junipe1'llsosteosperma(Torr.)Little. Univ.Ariz.Herb. No. 10604.
Gilbertson, R. L. 1974. Fomes demidoffii (Lev.) Cooke on Juniperus
osteosperma (Torr.) Little. Univ. Ariz. Herb. No. RLC 7090
RLC 10107.
Gilbertson, R. L.; Burdsall, H. H., Jr.; Larsen, M. J. 1975. Notes
on wood rotting hymenomycetes in New Mexico. Southwest
Naturalist. 19: 359-360.
Gilbertson, R. L.; Martin, K J.; Lindsey, J. P. 1974. Annotated check
list and host index for Arizona wood-fungi. Univ. Arizona Agric.
Exp. Sta. Techn. Bull. 209: 1-48.
Gilbertson, R. L.; McHenry, J. 1969. Check list and host index for
Arizona rust fungi. Univ. Arizona Agric. Exp. Sta. Techn. Bull.
186: 1-40.
Goodding, L. N. 1919. Gymnosporangium juvanescens Kerns on
Juniperus osteosperma (Torr.) Little. Univ. Ariz. Herb. No. 04.
Hawksworth, F. G. 1950. Poria (Antrociia) Ferox on Juniperus osteosperma (Torr.) Little. Rocky Mtn. For. & Ran. (Colo.) Herb. No. 5430-C.
Hawksworth, F. G. 1950. Trametes sepium Berk on Juniperus osteosperma (Torr.) Little. Rocky Mtn. For. & Ran. (Colo.) Herb. No. 5010-G.
Hawksworth, F. G. 1952. Uredo phoradendri H. Jacks on Juniperus
osteosperma (Torr.) Little. Rocky Mtn. For & Ran. (Colo.) Herb.
No. 6310-D.
Hedgecock, G. G. 1912. Poria (Antrodia) rimosa (Murr.) on Juniperus osteosperma. (Torr.) Little. Rocky Mtn. For & Ran. (Colo.)
Herb. No. 4147-E.
Hreha, A. M.; Weber, D. J. 1979. Distribution of Arceuthobium
divaricatum Engelm. and Phoradendron juniperinum Engelm.
ex A. Grayviscaceae on the south rim of Grand Canyon Arizona
USA. Southwest Naturalist. 24: 625-636.
Hurst, W. D. 1977. Managing pinyon-juniper for multiple benefits.
In: Ecology, uses, and management of pinyon-juniper woodlands.
USDA Forest Service General Technical Report RM-39. 48 p.
Kuchler, A. W. 1964. Manual to accompany the map potential
vegetation of the coterminous United States. American Geographical Society Publication. 36: 111.
Landis, T. D.; Helburg, L. B. 1976. Black stain root disease of pinyon
pine in Colorado. PI. Dis. Reporter. 60: 713-717.
Lanner, R. M. 1975. Pinyon pines andjunipers of the south-western
woodlands. In: The pinyon-juniper ecosystem: A symposium.
Utah Agriculture Experiment Station. 194 p.
Peterson, R. S. 1961. Arceuthobium campylopodium Engelm. onPinus
edulis Engelm. Shrub Sciences Laboratory, Provo, UT. Herb. No. 8329.
Peterson, R. S. 1962. Coleosporium l'ibicola Arth on Pinus edulis
Engelm. Shrub Sciences Laboratory, Provo, UT. Herb. No. 1001.
Peterson, R. S. 1967. Studies ofjuniper rusts in the West. Madrono.
19: 79-91.
Tausch, R. J.; Tueller, P. T. 1990. Foliage biomass and cover
relationships between tree and shrub dominated communities in
pinyon-juniper woodlands. Great Basin Naturalist. 50: 121-134.
Tegethoff, A. C. 1973. Known distribution of Fomes annosus (Fr.)
Cooke in the intermountain region. PI. Dis. Reporter. 57: 407 -410.
Tueller, P. T.; Beeson, C. D.; Tausch, R. J.; West, N. E.; Rea, K H.
1979. Pinyon-juniper woodlands of the Great Basin: Distribution, flora, vegetal cover. USDA Forest Service Research Paper
INT-229. 22 p.
Wagener, W. W.; Mielke, J. L. 1961. A staining-fungus root disease
of ponderosa, jeffrey, and pinyon pines. PI. Dis. Rep. 45: 831-835.
Walters, J. W.; Walters, N. R. 1977. Verticicladiella wagenerii
(Kend.) in the southwest. PI. Dis. Reporter. 61: 419.
Weber, D. J.; Gang, D.; Halls, S.; Nelson, D. L. 1995. Juniper
decline in the Natural Bridges National Monument and
Canyonlands National Park. In: Roundy, Bruce A.; McArthur, E.
Durant; Haley, Jennifer S.; Man, David K, comps. Proceedings:
wildland shrub and arid land restoration symposium. 1993 October 19-21, Las Vegas, NV. Gen. Tech. Rep. INT-GTR-315. Ogden,
UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 258-262.
Welch, L.; Weber, D. J. 1986. In vitro digestibility of Juniperus
osteosperma Torr. Little from 17 Utah sites. Forest Science. 32:
834-840.
USDA Forest Service Proceedings RMRS-P-9. 1999