Forest Health
The Forest Health staff of the Southwestern Region provides assistance and expertise to Federal, State, and Tribal land managers in Arizona and New Mexico concerning forest health conditions and issues.
We provide advice and support for projects to help prevent or suppress insect and disease outbreaks. Annually, we conduct survey flights to monitor forest health conditions and provide land managers with information on current issues, with an emphasis on detecting insect activity.
2023 Conditions Report
Our 2023 Conditions Report is now available, with forest insect and disease highlights from across the Southwestern Region.
2024 Damage Map
The 2024 Forest Health Damage Map shares draft map data as forest health surveys are completed.
Aspen Management
See new information on aspen health and management concerns in the following Western Aspen Alliance brief on invasive oystershell scale. For more information on oystershell scale see the recent State Forest Health Alert or our recent publication.
Tussock Moth Outbreaks
The native Douglas-fir tussock moth has been active the past couple of years defoliating trees in some forested around New Mexico. In 2024 activity by this insect increased and outbreaks are affecting specific areas on the Carson, Cibola, and Santa Fe National Forests.
Field Guides
Field Guide to Invasive Species
Learn about flora and fauna in the Southwest. A description for each insect and disease includes hosts, damage, symptoms, biology, and effects or impacts.
Weed Field Guide
New series of 33 field guides. 40+ species covered. Includes management guidelines.
Insect and Disease Surveys
With the assistance of our state forestry cooperative partners, we annually survey the forested areas of Arizona and New Mexico for forest health conditions. We conduct our surveys from aircraft to enable us to cover such a large area each year.
Aerial surveying enables us to monitor forest health conditions more efficiently and economically than other methods. During the surveys, we look for areas with dying trees (from bark beetles, drought, other factors), various types of defoliation, and abiotic impacts such as from storms and weather patterns.
The observer in the aircraft records the survey either by drawing the affected area on a map or using a digital sketchmapping system (Digital Mobile Sketch Mapping site).
Pictured here is an aerial photograph of Douglas-fir beetle infected trees.
The results of our surveys are distributed in the fall to land managers in the region, summarized, and used for analysis. Summary information is part of our annual Forest Insect and Disease Conditions Report.
For a comprehensive report of insect and disease activity in the region, please review our latest 2023 Conditions Report.
Forest health aerial surveys are also conducted by Forest Service and State partners throughout other parts of the country.
For information on our overall survey program please visit our national Forest Health Protection aviation site. Our national Forest Health Protection Mapping & Reporting site has applications to view and interact with forest health related data, including the ability to download ADS data.
Our current data are available for viewing through our ArcGIS Online Map Application.
GIS Data
GIS (Geographic Information System) data containing the results of our aerial surveys are available for download from the National Portal
Please Note:
U.S. Forest Service, Forest Health Protection (FHP) along with the Arizona State and New Mexico State Forestry Divisions strive to maintain an accurate Aerial Detection Survey (ADS) Dataset, but due to the conditions under which the data are collected, FHP and its partners shall not be held responsible for missing or inaccurate data. ADS are not intended to replace more specific information. An accuracy assessment has not been done for this dataset; however, ground checks are completed in accordance with local and national guidelines. Maps and data may be updated without notice. Please cite “USDA Forest Service, Forest Health Protection, Arizona State Forestry Division, and New Mexico State Forestry Division” as the source of this data in maps and publications.
Access ADS data by Forest Service Region from the National Program Page
Bark Beetles
Much of the Southwestern Region has periodically experienced severe drought conditions during portions of the past two decades, causing our forests to experience elevated water stress. As a result, several native bark beetles species attacked these drought-stressed trees, leading to elevated widespread tree mortality. When trees are healthy, and not stressed by drought or injured by fire, they are more resilient to bark beetle attacks. In addition, trees can be severely stressed in dense forest stands due to over competition for water and nutrients. Dense forest stands are also more conducive to bark beetle attacks, allowing pheromones to remain in the understory thus improving communication and providing a more suitable microclimate for beetle survival.
Higher than normal levels of tree mortality have been reported in Arizona during the winter and spring of 2021. Most of the mortality appears to be related to drought stress and pine engraver attacks on ponderosa pines. In particular, increased pine mortality has been observed on the Prescott, Kaibab and Coconino National Forests, and along the Mogollon Rim on the Apache-Sitgreaves National Forests. Pine mortality has been concentrated in lower elevation sites, southern exposures and where trees are chronically stressed due to intertree competition and dwarf mistletoe infection. The photograph below shows some of the tree mortality.
Dry Conditions
Bark beetles are known to attack water stressed trees and tree mortality was anticipated given the low amount of precipitation received over the previous year. Attacked trees may have pitch tubes, however, during dry years only the boring dust or frass (circled in the image below) may be present.
Status
Forest Health Protection will monitor the tree mortality with continued ground surveys and during our annual aerial surveys to determine the extent across the landscape. Results from these surveys will be available and reported in our annual conditions report.
Several species of bark beetle, including western pine beetle, roundheaded pine beetle, and pine engravers, killed hundreds of thousands of ponderosa pine on the Lincoln National Forest, New Mexico from 2011 to 2013 resulting from a drought period in southern NM during this period. Tree mortality was mapped primarily on the west side of the Sacramento Ranger District and areas of the Capitan Mountains of the Smokey Bear Ranger District.
Above: Aerial image of ponderosa pine mortality along the western slope of the Sacramento Mountains of the Lincoln National Forest in 2013.
From 2012 to 2016, elevated white fir mortality caused by the fir engraver bark beetle has been widespread across the Sandia Ranger District of the Cibola National Forest, New Mexico. Although severe drought conditions have alleviated, tree mortality continues in the area. The white fir mortality has been widespread across much of the northern parts of the ranger district.
Above: Fir engraver bark beetle (Scolytus ventralis) (left) and aerial photograph from 2015 surveys of old and new white fir mortality on the north end of the Sandia RD (right).
Above: Map graphic of 2015 aerial survey results from the Sandia Mountains, showing areas with tree mortality (red shaded areas). Tree mortality has been mapped in this area from 2011 through 2016.
Effects from Recent Wildfires
Recent wildfire events, including the Wallow (2011), Los Conchas (2011), Thompson Ridge, and North Fire (2016) wildfires have also stressed trees and predisposed Douglas-fir to attack by Douglas-fir bark beetle on the Apache-Sitgreaves National Forests in Arizona as well as the Gila and Santa Fe National Forests in New Mexico. In Arizona, we have also documented increased mountain pine beetle attacks in the southwestern white pines after the Wallow Fire on the Apache-Sitgreaves National Forests, and in the Schultz Fire on the Coconino National Forest. In the Wallow Fire, Forest Health Protection has worked collaboratively with the Apache-Sitgreaves National Forests to limit Douglas-fir and southwestern white pine mortality by removing infested trees as well as hanging bark beetle pheromone interruptants in developed recreation sites and Mexican spotted owl protected activity centers.
Above: Aerial photograph of tree mortality in an area affected by the Wallow Fire.
For current information on bark beetle activity, see our most recent annual conditions report available on the Publications page.
Tree Risk Management
The Forest Service inspects campgrounds and other developed sites for tree hazards in order to provide a safe environment for forest visitors. Insects and diseases that infest trees are a natural part of the ecosystem, providing food and habitat for wildlife. However, in developed sites, dead, decaying, or otherwise defective trees with a potential to fail and cause injury to people or property are identified and removed.
Forest Health Protection staff is available to provide training to federal land manager partners in tree risk assessment and mitigation. Record keeping is a very important aspect of the tree risk evaluation process. The assessment form provided below can be used or adapted by Forest Service personnel for their respective forest/district. An electronic version using ArcGIS Online and Survey123 is also available. Contact your respective Forest Health Protection zone for an Excel file that can be used develop a survey for each forest/district. The following additional resources are available for land managers.
- Email the Forest Health Tree Risk Program Managers
Field Guides
- Tree Risk Assessment and Hazard Tree Mitigation in the Southwestern Region (PDF, 20.4 mb)
USDA Forest Service, 2024. Southwestern Region, TP-R3-16-37.
- Field Guide for Hazard-Tree Identification and Mitigation on Developed Sites in Oregon and Washington Forests (PDF, 1.7 mb)
USDA Forest Service, 2014 Pacific Northwest Region, R6-NR-TP-021-2013.
- A Guide to Identifying, Assessing, and Managing Hazard Trees in Developed Recreational Sites of the Northern Rocky Mountains and the Intermountain West (PDF, 12.9 mb) USDA Forest Service, 2017. Northern Region, R1-17-31
Forms
- Tree Risk Assessment Form (PDF, 154 kb)
Form for documenting tree risk inspections.
Other Resources
- Hazard Tree Guidelines for Forest Service Facilities and Roads in the Pacific Southwest Region (PDF, 1.5 mb)
Angwin, P.A., Cluck, D.R., Zambino, P.J., Oblinger, B.W., and Woodruff, W.C. 2012. USDA Forest Service, Pacific Southwest Region, Report RO-12-01.
- How to Prune Trees
Bedker, P.J., O’Brien, J.G., and Mielke, M.E. 2012. USDA Forest Service, Northeastern Area, State and Private Forestry NA-FR-01-95.
Urban Forest Connections Webinar Presentations
- Tree Risk Assessments: Cutting Edge Science Meets Practical Applications
- Tree Risk Assessments for Municipalities
- Urban Tree Risk Management: A Community Guide to Program Design and Implementation (PDF, 8.1 mb)
Pokorny, J.D. 2003. USDA Forest Service, Northeastern Area State & Private Forestry, Report NA-TP-03-03.
Forest Health Publications and Resources
Forest Insect & Disease Conditions in the Southwestern Region
- 2023 (PDF, 13.65 mb)
- 2022 (PDF, 10.3 mb)
- 2021 (PDF, 12.2 mb)
- 2020 (PDF, 9.6 mb)
- 2019 (PDF, 9.0 mb)
- 2018 (PDF, 10.2 mb)
- 2017 (PDF, 6.7 mb)
- 2016 (PDF, 9.4 mb)
- 2015 (PDF, 5.5 mb)
- 2014 (PDF, 4.5 mb)
- 2013 (PDF, 2.8 mb)
- 2012 (PDF, 3.0 mb)
- 2011 (PDF, 1.5 mb)
- 2010 (PDF, 1.5 mb)
- 2009 (PDF, 1.6 mb)
- 2008 (PDF, 2.0 mb)
- 2007 (PDF, 737 kb)
- 2006 (PDF, 1.8 mb)
- 2005 (PDF, 1.1 mb)
- 2004 (PDF, 1.3 mb)
- 2003 (PDF, 1.0 mb)
- 2002 (PDF, 1.1 mb)
- 2001 (PDF, 168 kb)
- 2000 (PDF, 665 kb)
- 1999 (PDF, 152 kb)
- 1998 (PDF, 745 kb)
- Forest Health Monitoring in the Interior West: A Baseline Summary of Forest Issues, 1996-1991, RMRS-GTR-75, May 2001 (PDF, 2.5 mb)
- Strategy for Long-Term Management of Exotic Trees in Riparian Areas for New Mexico’s Five River Systems, 2005-2014 (Draft version, March 2004)
Produced by the New Mexico Interagency Weed Action Group (IWAG), an ad-hoc group representing numerous state and federal resource management agencies involved in weed management.
- Best Predictors for Postfire Mortality of Ponderosa Pine Trees in the Intermountain West, 2006, Forest Science 52:718-228 (PDF, 955 kb)
- Arizona Fivespined Ips, Ips lecontei Swaine, in the Southwestern United States, Forest Insect & Disease Leaflet 116, December 2008 (PDF, 529 kb)
- Bark Beetle-Caused Mortality in a Drought-Affected Ponderosa Pine Landscape in Arizona, USA, 2009, Forest Ecology and Management 275(4):1353-1362
- Bark Beetle Responses to Vegetation Management Treatments, 2009, in General Technical Report PNW-GTR-784: 25-38
- Development of Post-Fire Crown Damage Mortality Thresholds in Ponderosa Pine, 2010, International Journal of Wildland Fire 19:583-588.
- Effects of Mechanical Fuel Reduction Treatments on the Activity of Bark Beetles (Coleoptera: Scolytidae) Infesting Ponderosa Pine, 2006, Forest Ecology 230:55-68
- Engraver Beetles in Southwestern Pines (5/2003) (PDF, 73kb)
- Evaluation of Funnel Traps for Characterizing the Bark Beetle (Coleoptera: Scolytidae) Communities in Ponderosa Pine Forests of North-Central Arizona, 2008, Journal of Economic Entomology 101(4):1253-1265
- Evaluation of Insecticides for Protecting Arizona Cypress (Cupressus arizonica) and One-Seed Juniper (Juniperus monosperma) from Attack by Phloeosinus Bark Beetles, 2007, Arboriculture & Urban Forestry 33(3)162-167 (PDF, 6.9 mb)
- Evaluation of Insecticides for Protecting Southwestern Ponderosa Pines from Attack by Engraver Beetles (Coleoptera: Curculionidae: Scolytinae), 2006, Journal of Economic Entomology 99:393-400
- Factors influencing pine engraver (Ips pini Say) colonization of ponderosa pine (Pinus ponderosa Dougl. ex. Laws.) slash in Northern Arizona, 2008, Forest Ecology and Management 255:3541-3548
- Influence of Elevation on Bark Beetle (Coleoptera: Curculionidae, Scolytinae) Community Structure and Flight Periodicity in Pondersa Pine Forests of Arizona, 2008, Environmental Entolomology 37(1):94-109
- Influence of Temperature on Spring Flight Initiation for Southwestern Ponderosa Pine Bark Bettles (Coleoptera: Curculionidae, Scholytinae), 2008, Environmental Entomology 37(1):57-69
- Integrated Pest Management Guide: Arizona Five-Spined Ips and Pine Engraver (7/1991) (PDF, 2.3 mb)
- Lack of Genetic Differentiation in Aggressive and Secondary Bark Beetles (Coleoptera: Curculionidae, Scolytinae) from Arizona, 2008, Environmental Entomology 37(3):817-824
- Managing Slash to Minimize Colonization of Residual Trees by Ips and Other Bark Beetle Species Following Thinning in Southwestern Ponderosa Pine, The University of Arizona Cooperative Extension
- Mountain pine beetle voltinism and life history characteristics across latitudinal and elevational gradients in the western United States. 2014. Forest Science 60(3):434-449.
- Prescribed Fire Effects on Bark Beetle Activity and Tree Mortality in Southwestern Ponderosa Pine Forests, 2008, Forest Ecology and Management 255:119-128
- Retrospective Assessment of Partial Cutting to Reduce Spruce Beetle-Caused Mortality in the Southern Rocky Mountains, 2010, Western Journal of Applied Forestry 25:81-87
- Synergistic Effects of alpha-pinene and exo-brevicomin on Pine Bark Beetles and Associated Insects in Arizona, 2008, Journal of Applied Entomology 132:387-397
- Oystershell scale: An emerging invasive threat to aspenin the southwestern US, 2021
- Oystershell Scale: An Invasive Threat to Aspen Conservation, WAA Brief #8: May 2022
- Aspen Decline on the Coconino National Forest, 2008, In Proceedings of the 55th Western International Forest Disease Work Conference, 2007 October 15-19 (PDF, 1.4 mb)
- Comparison of Dwarf Mistletoe Behavior and Stand Development in Treated and Untreated Areas: 10-Year Monitoring on Jarista Mesa, R3-03-02, June 2003 (PDF, 262 kb)
- Decay and Discoloration of Aspen, Forest Insect & Disease Leaflet 149, May 2009 (PDF, 473 kb)
- Development of the White Pine Blister Rust Outbreak in New Mexico, R3-04-01, February 2004 (PDF, 449 kb)
- Dwarf Mistletoes and their Management in the Southwest, R3-FH-10-01, May 2010 (PDF, 2.3 mb)
- Dwarf Mistletoe Management and Forest Health in the Southwest, April 2000 (PDF, 481 kb)
- Effects of Three Prescribed Fires on Dwarf Mistletoe Infection in Southwestern Ponderosa Pine, R3-01-02, Revised March 2005 (PDF, 717 kb)
- Heterobasidion annosum and H. parviporum in the Southern Rocky Mountains and Adjoining States, 2010, Plant Disease 94:115-118
- Molecular characterization of Fusarium species associated with damping-off of conifer seedlings in tree nurseries, 2020, In Proceedings of the 66th Western International Forest Disease Work Conference, 2019 June 3-7
- Molecular identification and characterization of root disease pathogens in the western USA, 2020, In Proceedings of the 66th Western International Forest Disease Work Conference, 2019 June 3-7
- Populus tremuloides Mortality Near the Southwestern Edge of its Range, 2012, Forest Ecology and Management 282:196-207
- Survival and Sanitation of Dwarf Mistletoe-Infected Ponderosa Pine Following Prescribed Underburning, 2008, Western Journal of Applied Forestry 23(4):216-22
- White Pines, Blister Rust, and Management in the Southwest, R3-FH-09-01, March 2009 (PDF, 2.8 mb)
- Whitetail Dwarf Mistletoe Control Project: An Uneven-Age Management Case Study, R3-FH-11-01, September 2011 (PDF, 216 kb)
- Bark Beetle Activity Associated With Tornado-Damaged Ponderosa Pine in Northern Arizona, Poster Presentation from Forest Health Monitoring Workgroup Meeting, 2012 (PDF, 2 mb)
General Information
The following sites provide additional information on forest health issues:
- National Forest Health Monitoring (FHM)
The USDA Forest Service's National FHM group - National Forest Health Protection (FHP)
The USDA Forest Service's National FHP group - Forest Insect and Disease Leaflets
This series of publications covers a variety of forest insects and diseases
Insects and Diseases
- Bark Beetles of North America
Images and information on a variety of bark beetles - Field Guide to Insects and Diseases of Arizona and New Mexico Forests
- Field Guide to Diseases & Insects of the Rocky Mountain Region (PDF, 16.5 mb)
On-line version of Region 2's field guide - Insects & Diseases of Alaskan Forests (PDF, 9.5 mb)
Alaska's on-line field guide - Insects & Diseases of Trees in the South
On-line guide for the southeastern United States - Field Guide to Common Insect Pests of Urban Trees in the Northeast
On-line version of guide produced by Vermont Department of Forests - Forest Phytophthoras of the World
Information to aid in the understanding and management of Phytophthora species
Arizona Information
For more information on the conditions in Arizona:
New Mexico Information
For more information on the conditions in New Mexico: