Evaluation of a Roadside Survey Procedure for Dwarf Mistletoe on Ponderosa Pine in Colorado

Plant Disease ◽  
1985 ◽  
Vol 69 (7) ◽  
pp. 572
Author(s):  
Laura M. Merrill
Keyword(s):  
Ponderosa Pine ◽  
Dwarf Mistletoe ◽  
Roadside Survey

scholarly journals A Comparison of Wildlife Use in Broomed and Unbroomed Ponderosa Pine Trees in Northern Arizona

2004 ◽  
Vol 19 (1) ◽  
pp. 42-46 ◽  
Author(s):  
Robert L. Mathiasen ◽  
Gregg N. Garnett ◽  
Carol L. Chambers
Keyword(s):  
Ponderosa Pine ◽  
Wildlife Habitat ◽  
Passerine Birds ◽  
Dwarf Mistletoe ◽  
Erethizon Dorsatum ◽  
Resting Sites ◽  
Northern Arizona ◽  
Wildlife Use ◽  
Pine Trees

Abstract Dwarf mistletoe infections often induce structures known as witches' brooms that may provide an important wildlife habitat element. We compared evidence of wildlife use in broomed and unbroomed ponderosa pine trees at 12 mistletoe-infested sites in northern Arizona. We systematically sampled 12 broomed and unbroomed trees on each site (n = 144 broomed and 144 unbroomed trees) by climbing and inspecting each tree to document evidence of wildlife use. Broomed trees were used more frequently than unbroomed trees for wildlife activities including foraging/caching, nesting, and roosting/resting sites. We observed evidence of use by Abert squirrel (Sciurus aberti), porcupine (Erethizon dorsatum), and passerine birds in witches' brooms. Of the 226 brooms we examined, 23% (n = 52) contained evidence of wildlife use. Mammal use was found in 80% (n = 42) of the brooms and of these, 39 were used by Abert squirrel. We recommend that management agencies consider retaining some of these broomed trees to provide habitat for wildlife. West. J. Appl. For. 19(1):42–46.

Dwarf mistletoe effects on fuel loadings in ponderosa pine forests in northern Arizona

2007 ◽  
Vol 37 (3) ◽  
pp. 662-670 ◽  
Author(s):  
Chad Hoffman ◽  
Robert Mathiasen ◽  
Carolyn Hull Sieg
Keyword(s):  
Ponderosa Pine ◽  
Fire Behavior ◽  
Fuel Loading ◽  
Dwarf Mistletoe ◽  
Forest Fuels ◽  
Ponderosa Pine Forests ◽  
Northern Arizona ◽  
Basaltic Soils ◽  
Four Levels ◽  
Fuels Treatments

Southwestern dwarf mistletoe ( Arceuthobium vaginatum (Willd.) J. Presl ssp. cryptopodum ) infests about 0.9 million ha in the southwestern United States. Several studies suggest that dwarf mistletoes affect forest fuels and fire behavior; however, few studies have quantified these effects. We compared surface fuel loadings and predicted fire behavior among four levels of dwarf mistletoe infestation (none, light, moderate, and severe) in a total of 239 plots on 11 sites on basaltic soils in northern Arizona. In each plot we measured tree attributes, dwarf mistletoe rating and surface fuel loading. Stands severely infested by dwarf mistletoe had lower (P < 0.05) tree density and higher snag density, but higher (P < 0.05) total surface fuel loadings and total fuel loadings >7.62 cm and <7.62 cm, than non-infested stands. However, there were no statistical differences in any canopy fuel variables among infestation classes. Predicted fire behavior indicated that the wind speed required to promote the spread of a surface fire into the canopy was lower in severely infested stands than in non-infested stands. These results suggest that stands in northern Arizona that are severely infested with dwarf mistletoe should be priority areas for fuels treatments.

scholarly journals Western Dwarf Mistletoe Parasitizing Colorado Blue Spruce and Norway Spruce in California

Plant Disease ◽  
1998 ◽  
Vol 82 (3) ◽  
pp. 351-351 ◽  
Author(s):  
R. L. Mathiasen ◽  
J. R. Allison ◽  
B. W. Geils
Keyword(s):  
Norway Spruce ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Natural Infection ◽  
Dwarf Mistletoe ◽  
First Report ◽  
Blue Spruce ◽  
Northern Arizona ◽  
Jeffrey Pine ◽  
Shoot Production

Western dwarf mistletoe (Arceuthobium campylopodum Engelm.), a common parasite of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (Pinus jeffreyi Grev. & Balf.), was found parasitizing planted Colorado blue spruce (Picea pungens Engelm.) and Norway spruce (Picea abies (L.) H. Karsten) in Upper Cuddy Valley, CA (Kern County, T. 9 N., R. 21 W., Sec. 25). One tree greater than 6 m in height of each spruce species was infected and both trees were within 12 m of a Jeffrey pine severely infected with western dwarf mistletoe. Five to 10 branches were infected on each tree and a few of these had abundant mistletoe shoot production, which allowed identification of the parasite. This is the first report of western dwarf mistletoe on Colorado blue spruce. Although this is the first report of natural infection of Norway spruce in California, this mistletoe/host combination has been reported by Weir from artificial inoculation (2) and collected by Russell in central Washington (1). We recommend that these spruce species not be planted within 15 m of pines infected with western dwarf mistletoe. Specimens of western dwarf mistletoe on Colorado blue spruce and Norway spruce were collected and deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff. References: (1) F. G. Hawksworth and D. Wiens. 1996. Dwarf Mistletoes: Biology, Pathology, and Systematics. USDA Agric. Handb. 709. (2) J. R. Weir. Bot. Gaz. 56:1, 1918.

scholarly journals Dwarf Mistletoe-Induced Mortality in Northwest Ponderosa Pine Growing Stock

2001 ◽  
Vol 16 (3) ◽  
pp. 136-141 ◽  
Author(s):  
Lewis F. Roth
Keyword(s):  
Ponderosa Pine ◽  
Dwarf Mistletoe ◽  
Growing Stock ◽  
High Incidence

Abstract After the careful removal of a ponderosa pine overstory infested with western dwarf mistletoe, the development of small poles and saplings in the infested residual thickets was followed in 48 plots over a period of 27 yr. The high incidence of mortality caused by mistletoe, which has not been previously reported to occur in significant amounts in Northwest ponderosa pine growing stock, was surprising and is important to management of the species. Death of 73, 38, 24 and 17% of the trees, respectively, occurred in the unthinned plots and those thinned to 500, 250, and 125 trees/ac. West. J. Appl. For. 16(3):136–141.

scholarly journals A Comparison of Rating Systems for Dwarf Mistletoe-Induced Witches' Brooms in Ponderosa Pine

2004 ◽  
Vol 19 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Thomas J. Parker ◽  
Robert L. Mathiasen
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Fire Ecology ◽  
Fire Behavior ◽  
Wildlife Habitat ◽  
Rating System ◽  
Sample Sizes ◽  
Rating Systems ◽  
Dwarf Mistletoe ◽  
New System

Abstract We compared four methods of assessing dwarf mistletoe infection and estimating volume of dwarf mistletoe-induced witches' brooms in ponderosa pine (Pinus ponderosa). Witches' brooms can provide important wildlife habitat and can influence fire behavior. We used Hawksworth's dwarf mistletoe rating system (DMR), Tinnin's broom volume rating system (BVR), an estimate of the percentage of live crown occupied by witches' brooms (PCB), and a new system, total broom volume (TBV). We rated 12,536 trees for southwestern dwarf mistletoe (Arceuthobium vaginatum subsp. cryptopodum) infection and broom volume. Using Hawksworth's DMR and Tinnin's BVR systems, we were not able to distinguish trees with different witches' broom volumes at all sample sizes. At all sample sizes, TBV ratings accurately and precisely identified amount of witches' broom volume. We recommend that TBV be used to quantify witches' broom volume in ponderosa pine where wildlife habitat and fire ecology are primary concerns. West. J. Appl. For. 19(1):54–59.

The effects of dwarf mistletoe, witches' brooms, stand structure, and site characteristics on the crown architecture of lodgepole pine in Oregon

2002 ◽  
Vol 32 (8) ◽  
pp. 1360-1371 ◽  
Author(s):  
R C Godfree ◽  
R O Tinnin ◽  
R B Forbes
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Soil Type ◽  
Pinus Contorta ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Stand Density ◽  
Dwarf Mistletoe ◽  
Site Characteristics ◽  
Crown Dimensions

We investigated the importance of lodgepole pine dwarf mistletoe (Arceuthobium americanum Nutt.) in determining the height to crown top (HCT), height to crown base (HCB), and live crown ratio (LCR) of 2025 lodgepole pine (Pinus contorta var. murrayana (Grev. & Balf.) Engelm.) growing over a 24-km2 study site in central Oregon. We compared the effects of infection and associated witches' brooms with those of site topography, soil type, shrub cover, stand density, and the abundance of mature ponderosa pine (Pinus ponderosa Dougl. ex P. Laws. & C. Laws). using multiple regression and path analysis. The density of dominant-size P. contorta was consistently the most important factor influencing HCT, HCB, and LCR across the study site. In dense stands, trees tended to have elevated crown bases due to self-pruning and, hence, lower values of LCR. Dwarf mistletoe and related witches' brooms uniquely explained 6.9% of the variance in LCR, which was close to that of dominant P. contorta (7.1%) and more than that of soil type (3.0%), but explained only 2.6% of the variance in HCB, which was less than that of dominant P. contorta (6.5%) and soil type (4.6%). Regression models suggest that heavily infected trees should be 18% shorter and have crown bases 37% lower than uninfected trees, while moderately infected trees should have an LCR over 20% larger than that of uninfected and heavily infected trees. We also found that the largest 25 heavily infected trees sampled were approximately 19% shorter and 11–13% smaller in diameter than the largest 25 uninfected trees. The results suggest that dwarf mistletoe can be an important factor in determining the crown dimensions of P. contorta but that these effects may be interpreted only in the context of site characteristics and stand structure.

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