Silviculture and Applied Forest Health Lab



Kristen M. Waring, Ph.D., Associate Professor (Google Scholar)

Graduate Students

Betsy Goodrich (Ph.D.)
Gennaro Falco (M.S.)
Tara Steadman (Integrated B.S.F. / M.F.)
Danny DePinte (Integrated B.S.F. / M.F.)
Ronnie Kyllo (M.F.)

Undergraduate Students

Connor Meehan

  • Adam Polinko, M.S. (2014). Stand response to western spruce budworm-caused defoliation and mortality in New Mexico.
  • Eric Vane, M.F. (2014). The impact of western spruce budworm on fire regimes in high elevation spruce-fir ecosystems.
  • Matt Blanford, M.F. (2014). Comparing actual and predicted diameter growth on the Mescalero Apache Reservation in New Mexico using Continuous Forest Inventory data.
  • Chris Looney, M.S. (2012). Cronartium ribicola effects on white pine growth, vigor and survival in Arizona and New Mexico.
  • Zak Thomas, M.S. (2012). Economic and ecological effects of forest treatments at Vermejo Park Ranch, NM.
  • Zach Bastow, M.F. (2012). Effects of forest treatments on tree carbon storage at Vermejo Park Ranch, NM.
  • Anna Higgins, M.S. (2011). Mixed conifer regeneration following fires of mixed severities of the last eleven years in Grand Canyon National Park.
  • Natalie Angell, M.S. (2011). Determinants of pygmy sugar pine in the Lake Tahoe Basin, U.S.A.
  • Chris Erickson, M.S. (2011). Old ponderosa pine growth and mortality responses to restoration treatments at Mt. Trumbull, AZ.
  • Katie Johnson, M.S. (2011). An analysis of fire monitoring handbook data from Zion National Park.
  • John Cothrun, M.F. (2009). Single tree selection and sustained yield planning in Northern California private forestry.
  • Melissa Fischer, M.S. (2009). Ponderosa pine characteristics associated with attack by the roundheaded pine beetle.

Ecology, management, genomics and conservation of southwestern white pine (Pinus strobiformis)

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SW White Pine
Southwestern white pine seedling

Investigators: Betsy Goodrich, Tara Steadman, Chris Looney, Tom Kolb, and Kristen Waring (NAU School of Forestry), Mary Lou Fairweather and James Jacobs (USDA Forest Service Forest Health Protection), Brian Geils and Sam Cushman (USDA Forest Service Rocky Mountain Research Station), Richard Sniezko (Dorena Genetic Resource Center, USDA Forest Service, OR), Amy Whipple and Lluvia Flores (NAU Department of Biology) and Andrew Eckert (Virginia Commonwealth University)

Description: White pine blister rust, a disease caused by a non-native invasive pathogen (Cronartium ribicola), threatens to de-stabilize populations of southwestern white pine, a little-studied species found in southwestern mixed conifer forests. Recently completed projects have investigated the distribution and severity of white pine blister rust in the Southwest (publication in prep) and the ecological role of southwestern white pine (Looney and Waring 2012, 2013).

Ongoing field projects are investigating the spatial distribution and abundance of southwestern white pine regeneration along a range of white pine blister rust severities and under differing silviculture treatments. We are also conducting a common garden study to quantify the geographic distribution of potentially adaptive traits, including growth, phenology, drought tolerance and potential growth costs to seedlings from parent trees with some form of resistance to Cronartium ribicola infection. Additionally, we began ongoing gene conservation efforts in 2012, collecting seed to be included in long-term cold storage to conserve the genetic diversity of this important species.

Our newest projects include 1. testing families from across Arizona and New Mexico for genetic resistance to white pine blister rust and linking resistance and adaptive traits between those families; 2) genomics and epigenetics, including development of single nucleotide polymorphisms (SNPs) from populations across Arizona, New Mexico and Mexico; and 3) cold hardiness variation in southwestern white pine across an elevation gradient using measurements of electrolyte leakage.

Tree Planting
Betsy Goodrich plants a southwestern white pine seedling in
New Mexico.

Funding: NAU School of Forestry Mission Research Program (McIntire-Stennis funds), USDA Forest Health Monitoring Evaluation Monitoring Program, USDA Genetic Conservation, NAU Genes to Environment Program (fellowship award to B. Goodrich), USDA Special Technology Development Program, NAU Technology Research Initiative Fund, NAU Hooper Undergraduate Research Award (to T. Steadman)

Cone Collection
Collecting cones and seeds from southwestern white pine.

Cone and seed insects of southwestern white pine (Pinus strobiformis)

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SW White Pine Cone
Southwestern white pine cone exhibiting evidence of insect

Investigators: Kristen Waring, Gennaro Falco, Danny DePinte, Rich Hofstetter, and Betsy Goodrich (NAU School of Forestry), Joel McMillan and John Anhold (USDA Forest Service Forest Health Protection).

Description: Cone and seed insects have not been well studied in most non-commercial tree species. Southwestern white pine (Pinus strobiformis) is a species of ecological significance in the mixed-conifer forests of the Southwest and Mexico but is threatened by recent outbreaks of the disease white pine blister rust, which causes stem and branch cankers that decrease reproductive fitness in mature, seed-bearing trees.

SW White Pine Cone
Conopthorus beetle in developing southwestern white pine

The lab has been collecting southwestern white pine cones and seeds since 2012 for gene conservation and within these collections we are continuing to inventory cone and seed insects associated with the southwestern white pine. During 2012 and 2013, we caged insect-damaged cones to rear insects, which we have been cataloging and identifying. Between May and August, 2014, we have been caging cones on individual trees as well as clipping and dissecting cones to identify insects and assess damage. Caged cones will be collected and dissected in early fall. We also plan to x-ray a subsample of seeds to quantify damage by the seed bug (Genus Leptoglossus). This marks the first attempt to fully document cone and seed insects associated with southwestern white pine and quantify their damage. Results of this project will be documented in a peer-reviewed publication as well as a photo guide for managers in the Southwest.

Funding: USDA Forest Health Monitoring Evaluation Monitoring Program and USDA Genetic Conservation

Stand response to western spruce budworm (Choristoneura occidentalis) defoliation and mortality in New Mexico

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NM Mixed Conifer
Matt Blanford (left) and Adam Polinko record measurements
on a heavily defoliated seedling in the dry mixed confer
forests of northern New Mexico

Investigators: Adam Polinko, Connor Meehan, Eric Vane, Kristen Waring, Matt Blanford

Description: Populations of western spruce budworm (Choristoneura occidentalis), a native defoliator of western conifers, have been at elevated levels in northern New Mexico for up to 20 years in some locations, causing extensive dieback and mortality of susceptible tree species (Douglas-fir, white fir, corkbark fir, and Engelmann spruce primarily). We are investigating how species composition and future stand structure and composition are being impacted by prolonged western spruce budworm defoliation in mixed conifer and spruce-fir forests.

Data Collection
Adam Polinko collects data on overstory
defoliation in a heavily defoliated spruce-
fir stand near Red River, NM.

Preliminary results indicate high mortality of true fir in spruce-fir forests, coupled with dying and defoliated spruce, leaving few live trees. We are also investigating the relationship between western spruce budworm outbreaks, climate, and site characteristics in spruce-fir forests using multispectral satellite imagery and modeled climate data. Using these methods, we will analyze current insect outbreaks in a changing climate, and predict the future behavior of outbreaks if certain climactic scenarios persist.


Funding: NAU School of Forestry Mission Research Program (McIntire-Stennis funds), NAU Intern-to-Scholars Program (C. Meehan), NAU Hooper Undergraduate Research Award (to M. Blanford)

Immediate post-fire conditions and response to the Wallow fire, eastern Arizona and the Duck Lake fire, northern Michigan

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Investigators: Kristen Waring and Eric Vane, Linda Nagel, Mike Falkowski and Erik Romstad (Michigan Technological University), Alex Finkral and Dave Fehringer (The Forestland Group)

Description: The Wallow fire burned over 500,000 acres in eastern Arizona during 2010, making it the largest fire in Arizona history. Using 16 permanent plots established between June 2010 and June 2011 and re-measured during summer 2012 and 2014, we are investigating the initial implications of the fire in the mixed conifer forest. We are analyzing fire severity using composite burn index, along with analyzing changes in fuel load, overstory and understory tree density and mortality, percent canopy cover, and reporting initial tree regeneration response.


Wallow Fire Extreme Wallow Fire Less Extreme
The Wallow fire in eastern AZ created a heterogeneous mosaic of both extreme
(left) and less extreme (right) changes in mixed conifer forest conditions.
3 years later
High severity area three years post-fire
dominated by hardwood sprouting species.

The Duck Lake fire of 2012 was the second largest wildfire in Michigan state history. During summer 2013, we installed 69 randomly located plots across varying fire severities in jack pine to assess initial forest response. We will be analyzing initial forest response by fire severity, using composite burn index to validate remote sensing fire severity. We will also use the Forest Vegetation Simulator to assess future forest productivity.

Jack Pine Seedling
Jack pine seedlings growing in the Duck
Lake fire area, Michigan.
Research Discussion
Investigators discuss the Duck Lake fire research.
Pictured left to right: Erik Romstad, Alex Finkral, Linda Nagel,
Mike Falkowski and Dave Fehringer.

Funding: The Forestland Group (Duck Lake fire research)

Exploring the heterogeneity of piñon-juniper vegetation in the four-corner states

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Piñon-juniper woodland
Piñon-juniper woodland, northern Arizona

Investigators: Gennaro Falco, Kristen Waring, John Shaw (Analyst; USDA Forest Service Forest Inventory and Analysis)

Description: Piñon-juniper is a ubiquitous vegetation type in the four-corner region of the Southwestern United States (Colorado, Utah, Arizona, and New Mexico). Management of piñon-juniper ecosystems has been complicated by the high degree of variability in plant community structure, species composition, historical disturbance regimes, and ecosystem processes. Regional land managers have expressed a desire for an empirically supported and management-oriented classification tool for piñon-juniper vegetation types. We are utilizing a US Forest Service – Forest Inventory and Analysis (FIA) dataset of piñon-juniper vegetation from the Southwest to i) elucidate the biotic, edaphic, disturbance, and climatic components related to piñon-juniper community composition and abundance Southwest; ii) validate previous piñon-juniper classification systems; and iii) develop a management-oriented identification tool for piñon-juniper vegetation types. Multivariate techniques are being utilized to meet these objectives and our identification tool will later be validated through field-testing.

Funding: USDA – National Institute of Food and Agriculture: “Translating Forest Science for Global Practitioners” Graduate Fellowship Grant (to G. Falco).