National Park ServiceU.S. Department of the Interior

Lava Beds National Monument

Hazard Tree Evaluations 2014

September 2014Steve HarveyBiological Science TechnicianDivision of Resource Management Lava Beds National MonumentNational Park ServiceUnited States Department of the Interior

Cover Photo. Hazard Tree Number 173, located adjacent to the Big Nasty Trail and in the vicinity of the Mammoth Crater Overlook. Though it is dead and has many woodpecker holes this tree was rated low priority in response to low target ratings.

Background

Visiting National Parks is a special experience enjoyed by millions of people every year. Western National Parks and Monuments are known for their diverse natural resources and beauty. Among these resources are trees, some of which are the oldest and tallest trees in the world. Unfortunately disease and natural processes can cause tree failure and in western parks and monuments this has resulted in injury, loss of life, and damage to facilities and property. The Pacific West Region Directive, PW-062, Hazard Tree Management provides guidance in the management of tree hazards which have the potential to cause injury or damage property within park developed areas.

Introduction

The Lava Beds National Monument Hazardous Tree Management Plan was developed for Lava Beds National Monument in the fall of 2008 by Resource Management employee Jennifer Tiehm. The National Park Service Pacific West Region Directive PW-062: Hazard Tree Management (2008) and the Crater Lake National Park Hazardous Tree Management Plan (2008) were used as references to create the protocol and design a form for evaluations. Beginning in 2008 the data was recorded by hand onto the form and entered into an excel spreadsheet. In 2014 it was determined that database should be transformed to a geodatabase and the survey should be completed on a Trimble Juno utilizing ArcPAD software. A feature class for the hazard tree evaluation was created in ArcGIS to record points at the location of the trees via the Global Positioning System (GPS) capabilities of the Trimble Juno. The geodatabase was populated with the fields utilized in the old database and additional fields were added to identify the number of stems (trunks) and the stump diameter of removed trees. The current geodatabase has 27 fields leveraged with 17 coded and range domains to hasten data collection and ensure data validity.

While nine tree species have been recorded at Lava Beds National Monument (Lava Beds) only three are found in developed areas. Of these, only Ponderosa Pine and Western Juniper are large enough to present a hazard and have been rated in this program. Western Juniper (Juniperus occidentalis) is the most common tree found within developed areas at Lava Beds. However, due to its limited range, criteria for evaluating hazardous conditions of this species were absent from the NPS Pacific West Region Directive PW-062 and the CRLA Hazardous Tree Management Plan. Additional research on Western Juniper ecology and mortality was performed in 2008 and 2010. This information was combined along with evaluation criteria from the two documents to finalize the Lava Beds hazard tree evaluation form.

Methods

For the 2014 survey the diameter at breast height (DBH) and height of each tree was measured. The DBH was determined using a DBH tape measure. The height of each tree was

obtained using a True Pulse 360 laser rangefinder which has the capacity to measure distance, inclination, azimuth, and height.

In addition to having measurements taken, trees were evaluated using the protocols developed in 2008. Each potential hazard tree was evaluated and rated based on its 1) defects and 2) potential targets.

Trees were given points for certain defects, with possible defect scores of 0-4. First the defects were assigned in three different categories, which range from minor defects to substantial. A point was assigned for a defect in each category even if it possessed more than one defect in that category. The prioritization of defects in each defect category was important to ensure the most severe hazard was accurately represented. The prioritization of the first category included ranking trunk scars over mistletoe due to the possible presence of dead wood at the center of the tree. Similar prioritizations were made for the other categories, with special note being taken to identify compromised structural integrity of both trunk and limbs. The fourth point in the defect category was assigned if a tree was leaning more than 5%. No matter how many defects a given tree possessed, it could only be assigned, at most, four defect points. For a full list of specific defects see Table 1.

Figures 1 & 2. Defects such as trunk scars and cracks can indicate compromised structural integrity and were prioritized over mistletoe.

Table 1. Defect Criteria

TREE DEFECT POINTS CRITERIA

ASSIGN 1 POINT if the tree exhibits one or more of the following defects:A) tree is deadB) mistletoe cankers/brooms present on more than one-half of the branchesC) insect frass / pitch tubes present (plus severe drought conditions exist for Western Juniper)D) dead top, or large dead branches (>5" diameter), or pronounced crooks, or forked top - except for Western JuniperE) cut or exposed roots (>25% of the root mass)F) tree drying or root rot present (except for Western Juniper)G) trunk scars or hollow butt (except for Western Juniper)X) Undefined

ASSIGN 1 ADDITIONAL POINT if the tree exhibits one or more of the following defects:A) tree is deadB) mistletoe cankers/brooms present & half of the branches are deadC) carpenter ants or wood boring beetles (not bark beetles) present with extensive boringD) dead top, or large dead branches (>8" diameter), or pronounced crooks, or forked top - except for Western JuniperE) cut or exposed roots (>50% of the root mass)F) root rot present with fading foliage, thinning crown, distressed cone crop, or resin flow at baseG) trunk scars >15yrs old or >2sq.ft, or hollow trunk, or swollen butt - except for Western JuniperH) numerous fruiting bodies (>5) of fungiX) Undefined

ASSIGN ANOTHER 1 ADDITIONAL POINT if the tree exhibits one or more of the following defects:A) tree is deadB) cut or exposed roots (>50% of the root mass), or rootmass lifting one one side, or disturbed soil presentC) large sections of loose bark (except Western Juniper), or large (>5") partially detached branchesD) more than 15 fruiting bodies of P. pini, or any large fruiting bodies (>8" diameter) of P. pini, F. pinicola, or E. tinctorium, or any fruiting bodies of the 3 previous species within 20ft on the ground or covering >25ft of the trunk, or a single conk of F. officinalisE) root disease present with fruiting bodies of F. annosus, P. weirii, A. mellea or advanced decay present in roots, butt, or mycelial fansF) large open cracks or hollow trunk (<6" of wood over 3/4 circumference of tree, or <1/2 radius of wood over 3/4 circumference of trees <24" diameter)X) Undefined

Each tree was also evaluated in relation to its potential targets. Each tree with a defect had to have an associated target. Target use and target values were evaluated and targets were given a low, moderate, or high rating for both use and value (Table 2).

The Target Use category has three different ratings: Low, Moderate, or High. Low-use targets include trails, roads, and the maintenance bone yard, which are not frequented as often as other areas of the park. Moderate-use targets include picnic areas, parking lots, unoccupied historic structures, and other structures. These targets are visited more frequently than low-use

areas, but have no overnight occupation. High-use targets have continuous occupation during the day or overnight occupation seasonally or year-round. Several high-use targets include campgrounds, employee housing, headquarters, and the visitor center.

The Target Value category also contains three ratings: Low, Moderate, and High. Target areas are rated low when there will be no impact to structures or vehicles. For example, signs and picnic areas are low-value targets. Moderate value targets include low use parking lots as well as heavily-used trails and overlooks, where there is still no potential to impact structures. High value targets include structures and places which are frequently occupied, such as campsites and buildings.

Table 2. Both the Target Use and Target Value ratings are combined to give a Target Score

Target Use Score Target Value Score Total Target Score

Low Low 1Low Moderate 1

Moderate Low 1Low High 2High Low 2

Moderate Moderate 2Moderate High 3

High Moderate 3High High 3

After both the defect and the target ratings were combined to give each tree a total rating (Table 3). After adding these scores, the total rating could be between 1-7. Based on this sum, each tree was assigned a priority. Trees with 1-3 total points were labeled “low priority”. Trees with 4-5 total points were labeled “moderate priority”. Trees with 5 total points and 3 defect points or 6 total points were labeled “high priority”. Trees with 7 points were labeled “extreme priority”.

Table 3. Total Points and Corresponding Treatment Priority Ratings

Total Points Treatment Priority1-3 Low4-5 Moderate

5 (with 3 defect points)-6 High7 Extreme

Trees that had previously been evaluated and were cut down, whether due to extreme and high ratings or not, were recorded and identified as “removed” in the geodatabase. Their defect was recorded as dead and their potential target, its use and value was noted to satisfy data entry

requirements in the collection protocol of the geodatabase. Once a tree has been recorded as “removed” it does not need to have its record updated.

Results

In 2014, the sixth year of the program, a re-evaluation of all of the previously monitored hazard trees at Lava Beds was completed as is specified in the protocol. The 2014 survey also added trees encountered that qualified for a hazard rating from the 31 zones identified as having a potential target. Height and trunk diameter measurements were obtained for all the trees as specified in the 2008 protocol. Forty one new trees were added to the inventory in August and September of 2014 and records for six that had been removed were corrected. Of those forty one new trees eleven trees were located in employee housing, sixteen in campground loop B, and six trees were added to campground loop A. All the new trees had a rating of low or moderate. New trees also were photographed for documentation.

Figures 3 & 4. Hazard Tree # 107 seen in 2009 and 2014 is located in employee housing and has noticeably declined in health. Unlike the tree on the cover the target use and value ratings for this tree are high. It is nearly dead, rated high, and its removal is recommended.

The results of the 2014 survey of all hazard trees indicate that the areas of most concern continue to be campground loop B and employee housing. Many trees in these areas seem to show signs of steady decline. Whether this is a result of drought conditions in 2013 and 2014 or some other reason is unclear. The fact that juniper trees in these areas, particularly in campground loop B,

suffer from compaction of soils around their roots is one possible reason for compromised health.

Forty nine percent of the 80 trees assigned a hazardous rating in campground loop B were cited for either trunk scars or dead tops. The presence of mistletoe on these trees was significant (>50%) though not always recorded due to the fact that its ranked priority was not as high as a defect that indicated loss of structural integrity. The presence of mistletoe on these trees is likely an indication of stress, but does not in and of itself denote a hazard. The concern here for threats to people and property comes from trunk failure as well as falling limbs and tree tops. Of the 80 trees in campground loop B the scarring of trunks (and exposed roots) was noted on sixteen of the trees and was rated as a moderate defect (Defect 2) on five of those trees and a severe defect (Defect 3) on one. All of these trees and one additional tree were given a priority rank of high and should, according to the Lava Beds Hazard Tree Management Plan, be either mitigated or removed.

Fifty six percent of the 43 trees assigned a hazardous rating in employee housing were cited for either trunk scars or dead tops. Five of these trees had both trunk scars and dead tops as defects. Only one of these trees (124) ranked a high priority in part due to a third defect and its location adjacent to both the playground and the road. Two (109 and 125) of the 43 were ranked moderate and two (181 and 182) were ranked low priority. The other tree (107) ranked with a high priority in the employee housing area is located between the seasonal apartments and has declined significantly in the six years of monitoring. It is expected to reach final decline in the next few months and due to its proximity to an employee residence should be removed in the fall of 2014.

Two trees (65 and 66) located in the group campground have dead tops that comprise seventy five percent of their height. They are ranked with a moderate priority and are on the edge of the camping area. While not in an area of high use, they should be evaluated to determine whether the dead tops should be removed

2014 Treatment Recommendations

As of the beginning of September 2014 the hazard tree geodatabase contains 182 trees that will need continued monitoring in the future. There are 127 trees with a priority rank of moderate that will need to receive annual evaluation in 2015 (Table 4) as per the 2008 protocol. Of the thirty

Table 4. Number of Trees with Each Rating

Priority Rating Number of TreesLow 46

Medium 125High 6

Extreme 0Removed 6

one defined developed areas in the monument that are to be surveyed only fourteen currently have hazard trees (Table 5).

Table 5. 2014 Hazard Tree Ratings by Developed Area

Developed ZoneLow

Potential Failure

Moderate Potential Failure

HighPotential Failure

ExtremePotential Failure

Total Number

of Hazard Trees

Captain Jack's Stronghold Picnic Area 7 7

Mammoth Crater 3 3Heppe Cave Parking Lot 1 1

Mushpot Cave Picnic Area 2 1 3Cave Loop 1 1

Visitors Center 1 1Fleener Chimneys Picnic

Area 2 2

Valentine Cave Parking Lot 3 3

Maintenance Bone Yard 2 3 5Headquarters 4 5 9

Campground Loop A 2 24 26Employee Housing 13 27 2 42

Campground Loop B 9 61 7 77Group Campground 2 2

There are nine trees that are rated high priority and should be evaluated for removal before winter 2014 begins.

Tree 107 in employee housing has declined in health significantly since evaluations began in 2008 and should be removed.

Tree 124 is located in the playground at employee housing and has four defects. Two additional trees (125 and 187) located in the playground, have dead branches that

can be mitigated through branch removal. Campground loop B [sites B3 and B4] has seven trees rated high priority (trees 27, 28, 33, 96, 206, 208, and 209).

Three trees (27, 28, and 196) are small trees located next to one another. These trees have significant defects but pose little threat to life.

Four trees (33, 206, 208, and 209) are larger and should be evaluated for removal. Two trees with moderate ratings (207 and 210), but significant defects, are located

between trees that have received a recommendation for removal (208 and 209). These trees (207 and 210) have hollow trunks and are likely to be upgraded to a high priority

status in the near future. Given their location in an area of high target value and use consideration of their removal would also realistic.

All tree mitigation recommendations must be reviewed and approved by the Chief of Resource Management prior to mitigation actions.

Future Recommendations

In past years, it has been reported that locating evaluated trees has sometimes been difficult due to the inaccuracies of the GPS collection and disparities with the aerial images used for GIS mapping. Fortunately, a photographic record of the trees evaluated has been kept. These photos have been beneficial in relocating and confirming the identity of specific trees. Continuing this protocol is recommended, as it not only helps identification but allows for additional visual assessment of the evolution of a tree’s condition since it was initially inventoried. Photos were taken of trees added to the inventory in 2014 and it is recommended this practice be continued. A document that was created, in 2014, with maps and previously inventoried tree photographs was used throughout field inventorying to assure accuracy. Storage of these photos in the same location as the geodatabase, metadata, and associated documentation is also recommended. Currently this is stored at (R:) > GIS_Projects > LABE > BIOL > 2014 > LABE_BIOL_2014_02_Hazard_Tree.

Guidelines for the re-evaluation of trees rated as hazards are addressed in the Lava Beds Hazardous Tree Management Plan and should be followed (Table 6). Since seventy percent of the trees in the inventory are rated moderate adequate time will need to be set aside for the 2015 survey. Particular attention should be paid to the trees in Campground Loop B. Many of these trees are in decline and are likely receive a higher priority rank in the near future. Efforts to offset these losses in an area of high use by replanting trees such as ponderosa pine and shrubs such as chokecherry could serve to preserve the aesthetic values for future visitors.

Table 6. Timeline for Hazard Tree evaluations at Lava Beds National Monument for 2015 - 2020

Evaluation Year

Annual Evaluations(Moderate Priority)

Every 3 Years Evaluations

(Low Priority)

Evaluations of All Trees in Developed Zones (every 6 years)

2015 Yes No No2016 Yes No No2017 Yes Yes No2018 Yes No No2019 Yes No No2020 Yes Yes Yes

The use of geographic information systems (GIS) has been helpful in carrying out the hazard tree program successfully in the past. With the migration of the program, from one conducted using an Access database and GPS units to a GIS leveraged geodatabase, understanding and utilizing GIS will be essential. The hazard tree program will benefit greatly by the accuracy and efficiency this change brings, but certain GIS skills will be required. ArcGIS software and Trimble handheld GPS units with ArcPAD are the currently used tools. The ability to create and edit geodatabases, check them in and out of the handhelds, and assess the data through queries are all skills needed by the survey team. Making sure evaluators have these skills is recommended.

At the completion of the first six year cycle of evaluations there have been substantial changes in data collection methods for the hazard tree program. Additionally, there has also been a chance to significantly assess the protocol criteria. It would therefore be a good idea to revise the 2008 Hazard Tree Management Plan for Lava Beds National Monument in the near future to reflect these ameliorations.

Conclusion

The transfer of the hazard tree evaluation program from a database to a geodatabase capable of geospatial and attribute data collection is an important step in creating a more precise and efficient method of implementation. This year’s survey was also expedited by the use of the True Pulse rangefinder to measure tree heights. Continued monitoring of trees within the monument for health and potentially hazardous failure is not only needed to protect people and property but may in the future shed light on the effects of human activity and climatic changes on the vegetation and natural resources at Lava Beds National Monument.

References

National Park Service, Pacific West Region. Pacific West Region Directive, PW-062, Hazard Tree Management. 2008

Iwaki, A; Mateljak, J; and Larson, D. 2010. Hazard Tree Assessment: 2010 Evaluations. Natural Resource. Lava Beds National Monument Resource Management Data Series. National Park Service, Tulelake, California.

Tiehm, Jennifer. Hazard Tree Evaluations 2008. Division of Natural Resource Management. Lava Beds National Monument, Tulelake, California.

Tiehm, Jennifer. Lava Beds National Monument Hazardous Tree Management Plan. 2008. Division of Natural Resource Management. Lava Beds National Monument, Tulelake, California.

Fawcett, Laura. Hazard Tree Evaluations 2011-2012. Division of Natural Resource Management. Lava Beds National Monument, Tulelake, California.