Guidance on Air Quality and Air Quality Related Values

Vital Signs Monitoring

in National Parks

Tonnie Maniero

National Park Service

Air Resources Division

### August 17, 2001

## Introduction

Air pollution damages resources and values that national parks have been
set aside to protect. The National Park Service (NPS) has responsibility
to remedy and prevent damage to air quality and related values.
Comprehensive scientific information is essential to understand and
document air quality conditions and effects of air pollution on park
resources. More than ten years of monitoring in several parks shows that
air pollution is degrading visibility, injuring vegetation, changing
water and soil chemistry, contaminating fish and wildlife, and
endangering visitor and employee health. Information generated through
the existing NPS air quality monitoring network and related research
programs has been used by NPS managers to secure substantial pollution
reductions at specific industrial facilities, to persuade States to
limit emissions from new pollution sources, and to bolster the U.S.
Environmental Protection Agency's (EPA) promulgation of more stringent
air pollution regulations.

## Servicewide Air Quality Strategy

##  Long-term protection of air quality in the National Park System requires a sustained effort to monitor air quality and related values and to enhance scientific understanding of how air pollution affects resources. To that end, the NPS developed an Air Quality Action Plan (The Plan) as part of the Natural Resource Initiative. Among other things, the Plan proposes to expand and enhance the current air quality monitoring network to ensure adequate representation of ecoregions, with emphasis on units most threatened by air pollution or most vulnerable to degradation. Other aspects of the Plan include funding for enhanced ambient monitoring and for short-term (up to 3-year) ecological effects projects. The Plan's budget includes an additional \$3 million over 5 years to support expanded ambient air quality and effects monitoring. Also, the Plan requests 35 additional field-based FTEs to support: 1) 0.5 FTE at all parks conducting air quality monitoring, and 2) ten full-time air quality specialists which will be strategically located in parks or field offices to provide expertise in the analysis and use of air quality information collected.

As part of the implementation of the Plan, the Air Resources Division
(ARD), in consultation with field staff and others, will identify
critical gaps in the Servicewide monitoring network and develop a
strategic plan for additional monitoring, taking into account scientific
needs and air quality improvement goals. To aid this effort, the ARD has
contracted with the University of Denver (DU) to develop a GIS-based map
that uses data from all federal, state, and locally operated air quality
monitors throughout the United States to interpolate (estimate) air
quality data for each NPS unit in a Vital Signs Network. DU will also
evaluate the level of confidence in each of the interpolated values. The
DU project should be completed in the fall of 2001. The ARD anticipates
that the 32 Vital Signs technical committees will identify ambient air
quality and effects monitoring needs in each Vital Signs Network. When
possible, the Network-specific needs will be incorporated into the
Servicewide air quality monitoring strategy. If identified local needs
do not fit into Servicewide needs, ARD will help the Networks seek
funding from other sources.

**Ambient Air Quality Monitoring**

The Servicewide air quality monitoring strategy will help ensure NPS
compliance with the Clean Air Act and associated regulations, the NPS
Organic Act, and the Government Performance and Results Act (GPRA) as
well as develop the comprehensive scientific information that is
essential to understand and document air quality conditions in parks. To
that end, the ARD has identified the following list of core ambient air
quality parameters that should be monitored in each Network.

-   Wind speed and direction (adjacent to pollutant monitor(s))

-   Relative humidity (adjacent to pollutant monitor(s))

-   Ozone (O~3~)

-   Wet deposition (including pH, sulfate, nitrate, and other ions)

-   Atmospheric particulates (including sulfate, nitrate, ammonium, and
    elemental and organic carbon)

ARD also recommends that sulfur dioxide (SO~2~) monitoring be conducted,
using continuous analyzers or weekly filter-pack measurements, in parks
located near large cities or other significant sources of SO~2~
emissions.

Chemical transformation, topography and elevation can influence air
pollutant concentrations. For example, concentrations of SO~2~ are high
close to a source, while downwind of the source, SO~2~ is converted to
sulfate and sulfuric acid, which contribute to acid deposition and
visibility impairment. Wet deposition of nitrate and sulfate is usually
greater at high elevations than low elevations due to increased
snowfall. Ozone concentrations are frequently higher on ridgetops and in
major river drainages with steep topography. Therefore, pollutant
concentrations can differ significantly within a Network and even within
a large, topographically complex park. The Network technical committee
should ensure that existing and proposed monitoring adequately represent
the range of pollutant concentrations in the Network (ARD can assist
with this evaluation).

In addition to the NPS, the U.S. Fish and Wildlife Service, the U.S.D.A.
Forest Service, states, and EPA conduct ambient air quality monitoring.
Network technical committees should identify all ambient monitoring
sites that occur in or near the area that encompasses the Network. These
sites should then be evaluated to determine how well they represent the
Network (Again, ARD can help Networks acquire this information). In many
cases, sites are part of a national ambient air quality monitoring
network. For example, ozone, SO~2~ and particulate matter data that are
collected using EPA protocols, and that meet EPA data quality criteria,
are entered into EPA's Aerometric Information Retrieval System (AIRS),
which provides summary data via the Internet (protocols for gaseous
pollutant and meteorology monitoring, and related information, available
at http://www2.nature.nps.gov/ard/gas/network.htm#ops). Similarly, wet
deposition data that are collected as part of the National Atmospheric
Deposition Program/National Trends Network (NADP/NTN) are available on
the Internet (protocols for NADP/NTN data collection available at
http://nadp.sws.uiuc.edu/lib).

Estimated capital and operating costs of monitoring the core, and other
common, air quality parameters are provided in the table below. Note
that these are very rough estimates since factors such as remoteness of
the site, existence of line power, *etc.* may greatly influence costs.

  -------------------------- ---------------------- ----------------------
  **TYPE OF MONITOR**        **CAPITAL COST**       **ANNUAL COST**

  **Visibility:**                                   

  Camera                     \$8,000                \$5,000

  Nephelometer               \$29,000               \$25,000

  Transmissometer            \$46,000               \$25,000

  Particulates               \$15,000               \$30,000

  **Criteria or Gaseous                             
  Pollutants:**                                     

  Equipment shelter,         \$30,000-\$40,000      \$500
  facilities, site                                  
  preparation                                       

  Utilities -- power, phone, \$6,000-\$20,000       \$2,000
  access                                            

  Ozone                      \$25,000               \$28,000

  Filter-pack sulfate,       \$15,500               \$12,000-\$15,000
  nitrate, nitric acid, and                         
  SO~2~                                             

  Continuous SO~2~           \$25,000               \$26,000

  **Meteorology** (wind      \$15,000               \$10,000
  speed, wind direction,                            
  temperature, relative                             
  humidity, solar radiation,                        
  and precipitation)                                

  **Wet Deposition           \$12,000-\$15,000      \$7,000
  (NADP/NTN)**                                      

  **Station Operator**       \-\--                  \$8,000-\$20,000
  -------------------------- ---------------------- ----------------------

For some Networks, additional ambient air quality-related concerns may
be identified. For example, other parameters that could be monitored
include dry deposition, snow chemistry, fog chemistry, pesticides,
dioxins, hazardous air pollutants, mercury, and other trace metals. For
parks in urban areas, carbon monoxide, volatile organic compound, or
nitrogen dioxide monitoring may be warranted. In some situations, it may
be desirable to perform tracer studies to identify the primary sources
of pollution affecting the parks.

Monitoring protocols already exist for many of the ambient air quality
parameters. The ARD will coordinate development of additional protocols
(with outside experts, if necessary) if a Servicewide need is
identified.

**Monitoring Air Pollution Effects on Resources**

Air pollution-sensitive resources are typically called air quality
related values, or AQRVs. Resources differ significantly in their
sensitivity to air pollutants, so air pollution effects will be a
greater concern for some Networks, and some parks, than others. For
example, fumigation studies have identified a handful of species,
*e.g.*, Ponderosa pine, black cherry, and others, that are sensitive to
ozone. While the level of sensitivity differs based on genotype and
local environmental conditions, these species still represent the best
candidates for ozone injury surveys. If known ozone-sensitive species do
not occur in the Network, an intensive and expensive effort would be
required to identify the most appropriate species to monitor. High
elevation alpine lakes and low order streams on granitic bedrock
(resistant to weathering) are most susceptible to acidification.
Watersheds on easily weathered bedrock are not likely to be sensitive to
acid deposition. Therefore, it is important to consider the potential
sensitivity of resources in the Network and evaluate the ambient air
quality data to determine if there is a need to monitor AQRVs.

Each Vital Signs Network technical committee should compile and evaluate
existing information on park resources that are potentially sensitive to
air pollution. This information should include lists of air pollution
sensitive plant species in each park (the lists can be compiled by
comparing park plant lists to master lists of air pollution sensitive
species), data on surface water chemistry, and reports of any air
pollution effects monitoring (*e.g.*, foliar injury surveys,
invertebrate or fish studies, soil monitoring) that would be relevant to
the Network. Note that such monitoring may have been conducted by
another agency in the area or by a park in another Network.

Resource monitoring for air pollution effects can often be incorporated
into programs developed to monitor for other stressors. For example, if
a Network chooses to initiate a lake or stream monitoring program,
including water quality parameters such as pH, acid neutralizing
capacity, conductivity, and others will provide information regarding
sensitivity to atmospheric deposition. Concurrent aquatic biota surveys
(*e.g.*, phytoplankton, macroinvertebrates, fish) could indicate if
atmospheric pollutants are affecting sensitive species. Ozone injury
surveys could be incorporated into a general vegetation monitoring
program. Technical committees should explore opportunities for
integrating air pollution effects monitoring with other resource
monitoring programs in the Network. The ARD can provide monitoring
protocols for surface water chemistry and ozone injury monitoring, among
others (see appendices for examples). The ARD can also provide guidance
on the suitability of developed protocols for Networks and parks and
will coordinate development of additional protocols (with outside
experts, if necessary) if a Servicewide need is identified.

**Link to Water Resources Division-Funded Water Quality Monitoring**

The Network scoping process for water monitoring should consider the
potential effects of air pollutants on surface waters. Aquatic systems
can be good indicators of air quality. Deposition of sulfate and nitrate
can acidify surface waters with low buffering capacity, while nitrate
and ammonia deposition can eutrophy nitrogen-limited systems. Network
technical committees should evaluate the physical and chemical
characteristics of their aquatic systems, as well as examine
representative deposition data (*e.g.*, NADP/NTN) to determine the need
to monitor aquatic systems for air pollution effects. It is important to
determine if any aquatic systems in the Network are already impaired by
air pollution, as well as to identify and monitor air
pollution-sensitive systems to ensure they remain in pristine condition.

The physical characteristics of waters that are sensitive to acid
deposition include those at moderate to high elevation, in areas of high
relief, with flashy hydrology and minimal contact between drainage
waters and soils or geologic material that may contribute weathering
products to solution. Sensitive streams are generally low order.
Sensitive lakes are generally either small drainage systems or small
seepage systems that derive much of the hydrologic input as direct
precipitation to the lake surface. Streams sensitive to acid deposition
have been identified in parks in the Southern Appalachian Mountains,
while sensitive lakes have been identified in parks in the Sierra
Nevada, Cascade, and Rocky Mountains. Sensitive waters generally have
specific conductance below 25 μS/cm, acid neutralizing capacity (ANC)
below 100 μeq/l for episodic acidification (50 μeq/l for chronic
acidification), total base cation (calcium, magnesium, sodium, and
potassium) concentration below 100 μeq/l, and pH below 6.0.

It may be necessary to inventory systems that are potentially sensitive
to acid deposition before finalizing a water monitoring plan. Parameters
that should be measured as part of an inventory include specific
conductance, ANC, base cations, ammonium, sulfate, nitrate, chloride,
pH, and water temperature. In eastern U.S. parks, dissolved organic
carbon should also be measured. Water samples should ideally be taken at
the time of greatest sensitivity, *e.g.*, immediately following
snowmelt, and should follow appropriate sample collection, analysis, and
QA/QC procedures for acid deposition. If air pollution-sensitive or air
pollution-impaired waters are identified and incorporated into a water
monitoring program, in addition to the parameters listed above, it may
be appropriate to include some of the following chemical constituents:
dissolved organic carbon (for western U.S. parks), dissolved inorganic
carbon, dissolved oxygen content, total and dissolved phosphorus, total
and dissolved nitrogen, aluminum or other metals. It would also be
useful to collect some baseline soil chemistry data including cation
exchange capacity, base saturation, pH, and bulk density. Specific
sample collection protocols should be developed and documented.

In general, freshwater systems are phosphorus limited, while coastal
systems are nitrogen limited. Therefore, eutrophication will primarily
be a consideration for Networks with coastal parks. If eutrophication is
a concern, the parameters that should be monitored include chlorophyll
a, organic and inorganic nitrogen, total phosphorus, and turbidity.

Because sensitive surface waters generally have low concentrations of
many significant ions, it is critical that Networks use water quality
laboratories that are experienced in evaluating low ionic strength
samples. It is also important that ARD be able to compare results
between labs so that data can be "rolled up" to address national issues
and needs. To that end, selected laboratories should participate in
specific laboratory performance blind audit programs. For example, the
Canadian National Laboratory for Environmental Testing, National Water
Research Institute, Environment Canada sends out ten blind samples to
participating laboratories every six months and performs
inter-laboratory comparisons of the reported results.

Network staff should contact the ARD for assistance in evaluating
deposition and water quality data, identifying air pollution-sensitive
aquatic systems, and implementing air pollution-related water monitoring
protocols. This coordination will enable individual Networks to meet
their monitoring objectives, while at the same time ensuring the ARD can
use data collected by all Networks to promote Systemwide air quality
protection.

**Example of the Process**

In the spring of 2000, the ARD compiled air quality information to
assist in the monitoring scoping workshop for the Coastal and Barrier
parks Network which includes Assateague Island National Seashore (NS),
Cape Cod NS, Colonial National Historical Park (NHP), Fire Island NS,
Gateway National Recreation Area (NRA), George Washington Birthplace
National Monument (NM), Sagamore Hill National Historic Site (NHS), and
Thomas Stone NHS. Given the geographic extent of the Network, and the
proximity of a number of the parks to large cities, ARD staff surmised
that air quality parameters should be monitored in a number of locations
throughout the Network. Staff determined the location of the nearest
ozone, SO~2~, particulate matter, wet deposition, dry deposition, and
visibility monitors for each unit in the Coastal and Barrier parks
Network, and determined whether the parks were located in or near a
non-attainment area, *i.e.*, an area which is not in compliance with a
human health-based National Ambient Air Quality Standard. The ARD
concluded that most parks in this Network had adequate coverage of all
air quality parameters. Note that this assessment was based solely on
distances between monitors and parks, the DU products mentioned above
will improve the ability to assess how well off-site data represent
conditions in a park. From an ambient monitoring standpoint, ARD
recommended only that the Coastal and Barrier parks Network install an
ozone monitor at Assateague Island NS.

ARD staff also evaluated available resource data, including water
quality inventory reports prepared by the Water Resources Division.
Ozone sensitive plant species lists were developed for the six parks in
the Network that had plant lists in NPFLORA. All six parks have good
candidates for foliar injury monitoring, *i.e.*, black cherry (*Prunus
serotina*), trembling aspen (*Populus tremuloides*), and/or common
milkweed (*Asclepias syriaca*). Such monitoring should be considered if
ambient data indicate high ozone concentrations exist near a park. Fire
Island NS, Gateway NRA, George Washington Birthplace NM, Sagamore Hill
NHS, and Thomas Stone NHS are all located in or near ozone nonattainment
areas, so ozone injury surveys are warranted. Given the potential
acid-sensitivity of some of the ponds at Cape Cod NS, ARD recommended
water quality monitoring. During the scoping workshop, eutrophication
from nitrogen deposition was identified as a potential concern at a
number of parks in the Network.

**Data Management**

As discussed above, many of the ambient air quality monitoring data are
managed as part of national databases. These databases, as well as
statistical analyses and data summaries, are available to NPS staff via
the Internet. ARD will assume responsibility for ensuring that ambient
data collected under the Air Quality Action Plan undergo quality
assurance and are included in the appropriate national databases. The
Natural Resources Information Division is developing a natural resource
information management system called Synthesis. The Inventory and
Monitoring Program is encouraging Networks to use Synthesis to manage
data collected as part of the Vital Signs program, and ARD assumes
Synthesis would be a logical platform for managing air pollution effects
monitoring data. When Networks develop or populate databases for the
Vital Signs monitoring data, ARD can help identify appropriate data
fields for ambient air quality and AQRV information.

**Other Funding Sources**

Because it is likely that technical committees will identify far more
monitoring needs than can be funded by either the Vital Signs Program or
the monitoring component of the Servicewide air quality strategy, it is
important for Networks to explore other sources of funding. Other
possible internal sources of funding include park fee demo programs, and
park construction and maintenance funds which can be used to cover
capital costs such as purchase of air monitoring equipment and
monitoring shelters. The EPA, states, or local communities may be
interested in installing an ambient monitor in a park to collect
representative rural data. The EPA or other land management agencies may
be willing to collaborate on AQRV monitoring. The ARD can help Networks
prepare proposals for these and other potential sources of funding.

**Air Quality Data Websites**

NADP/NTN - http://nadp.sws.uiuc.edu/

Dry deposition - http://www.epa.gov/castnet/

IMPROVE - http://vista.cira.colostate.edu/improve/

Pollution sources and air quality data - http://www.epa.gov/air/data/

Pollution sources and air quality data -
http://www.epa.gov/ttn/rto/areas/

Pollution sources and air quality data - **http://www.epa.gov/agweb/**

Air toxics monitoring - **http://www.epa.gov/glnpo/air/**

Dioxin monitoring - **http://www.epa.gov/ncea/1page.htm#air**

Persistent Organic Pollutants (POPs) -
**http://www.chem.unep.ch/pops/default.html**

**Appendices**

(Note: The following protocols are provided for information purposes
only. It is important that Networks work with ARD or other experts in
air pollution effects monitoring to identify the most up-to-date
monitoring protocols and tailor them to Network needs.)

A. Protocol for Snowpit Chemistry Sampling

B. Protocol for High Elevation Lake Chemistry Sampling

C. Protocol for Identifying Ozone Injury on Eastern Forest Plants

D. Protocol for Identifying Ozone Injury on Western Pines

**APPENDIX A**

#### Protocol for Snowpit Chemistry Sampling

### U.S. Geological Survey

Water Resources Division

Denver, Colorado

[PROCEDURE]{.underline}

**1) Locate Site**

Be aware of avalanche danger along the route. If current storm
conditions indicate dangerous loading, choose an optional site in the
vicinity along a safer route. Use provided site maps, GPS, and altimeter
to locate sampling sites as close to designated locations as possible.

Sites should be chosen away from open roadways and in reasonably level
and sheltered clearings protected by trees where snow has not been
drifted or wind-scoured. The depth probes can be used to find a site of
uniform depth. Avoid onsite disturbances, such as excessive tree litter
and animal activity. It is imperative to choose site locations where
mid-winter melt is minimal. Avoid sunny, south-facing slopes. Check the
following:

a\) soil conditions beneath the snowpack should be relatively dry or
frozen.

b\) the snowpack should appear dry, there should be no visible
"free-water."

c\) 30 to 40 cm above the soil, snow temperatures should be \< 0 C.

If these conditions do not exist at the designated elevation, document
your observations and move to another location.

**2) Dig Snow Pit**

Once spot is selected for digging the pit, scribe a line perpendicular
to the sun to delineate the face of the pit wall, dig the pit so the
wall faces away from the sun, and avoid walking on or shoveling snow on
the snow surface for at least 1 m on the other side of the line (where
the pit wall will be sampled). For deep snowpits, the width of the
column should be narrow enough to cut steps in the sides so that the top
layers can be reached easily. Metal shovels can be used to dig the pit,
but the final vertical surface (approx. 50 cm wide) of the pit-wall
should be cut into with the clean plastic shovel for at least 10-20 cm.
The sample shovel and ice scoop are stored in a protective bag and
should be "snow-rinsed" before each site. Bisect pit wall with a 2 m
fiberglass ruler vertically with 0 cm at the soil-snow interface; do
sampling on one side, and temperature and density measurements on the
other side to avoid contamination of sample-face.

**3) Collect Samples**

A\) Duplicate snow columns:

Avoid contamination of very dilute snow samples from soil, forest
litter, sweat, etc. Discard the top 2 cm of snow at snow-air interface.
With all workers doing sampling wearing plastic gloves and liners
provided, one person holds zip lock bag open being careful not to touch
inside of bag, while another person scoops out a vertically
representative column of snow using the plastic shovel and ice scoop
provided. This process can be tedious in a deep and/or very consolidated
snowpack. One method that works well is to cut into the face with the
ice scoop about 1-2 cm and remove a column of these dimensions by 10-15
cm increments starting at the top and working downward. With shovel
cutting horizontally into the column to be removed, vertically scoop out
sample down to shovel with the ice scoop and dump this increment into
the zip lock bag. Repeat at 10-15 cm intervals downward until within
about 5 cm of soil. If soil gets on blade or scoop, plunge into snow
away from sample-face several times to clean. Fill bags to no more than
2/3 full to allow for closure of the bags. Shape bags in roughly
rectangular shapes before the snow sets up\--basketball shaped samples
do not store efficiently. Label bag with Site ID, Sample number (1 of 2,
2 of 2, etc.), date and time. Repeat.

B\) Field Blank

Each sampling team will do one field blank at a chosen site. Label zip
lock bag "Field Blank" and include Site ID, date and time of sample.
Pour field blank water over the shovel into the scoop. Also rinse the
scoop with the water and carefully pour into zip lock bag. Deflate the
bag as much as possible and seal.

**4) Complete Data Sheet**

A\) Fill in location, time, and conditions data, please be thorough but
concise.

B\) scale and label snowpack by 10 cm increments in "Depth" column on
datasheet. Clearly mark the air-snow and snow-soil interfaces. Make
physical measurements of:

1\) **thermometer precision:** place all thermometers in same layer of
snow and note precision before and after measurement of temperature
profile. If a single thermometer is out of calibration with the others,
set aside.

2\) **temperature profile:** at 10 cm intervals for pits \< 2 m deep, 20
cm intervals after that

3\) **density profile:** tare the balance with the density cutter, use
density cutter (1-liter) and lid to remove block of snow every 10 cm,
staggering every other sample.

4\) **hardness:** note the hardness of the snowpack (fist, 4 fingers, 1
finger, pencil or knife). Note ice lenses, discolored layers, unusual
snow, etc. in comments adjacent to layer.

5\) Sign the datasheet.

**5) Refrigerate Samples**

In the field, extra care should be taken to keep all samples frozen, by
keeping buried in snow...be sure to use flagging, so the samples are not
lost.

Upon return to the truck, place samples in coolers blue-ice blocks. To
avoid contamination of sample, do not use H~2~O-ice. Maintain
temperature below -5 degrees C.

**6) Ship Samples**

It is very important that samples do not arrive at the lab over the
weekend. Ship Monday through Wednesday only, overnight via Federal
Express.

For additional information, contact Don Campbell at dhcampbe@usgs.gov or
(303) 236-4882 x298.

**APPENDIX B**

**Protocol for High Elevation Lake Chemistry Sampling^(1)^**

# BASIC HYDROLOGY OF THE STREAM/LAKE CONTINUUM

To effectively design or conduct a surface-water sampling program some
knowledge of basic hydrology is needed. The chemistry of lakes and
streams is largely a function of what surfaces and substances the
inflowing water has contacted and for how long, and of some basic
physics driven by sunlight and wind. Thus, selection of lakes and
streams as monitoring sites needs to consider the hydrology of the
system so that the chemistry can be interpreted in the proper context.
If the site is to monitor the effects of acid rain or other atmospheric
inputs on surface water, then the hydrology should minimize the
possibility of processes that neutralize the atmospheric inputs.

Lakes and streams with factors that minimize the contribution of
weathering products (and thus maximize the influence of atmospheric
precipitation) have at least one of the following characteristics,
perhaps several:

1\) Large surface area of lake or stream to watershed area ratio.

2\) Subject to periods of great inflow discharge from snowmelt, rain on
snowmelt, intense thunderstorms, or hurricanes.

3\) Little exposed soil in the watershed or, at least, near the lake or
stream. Soil zones that do exist should be shallow.

4\) Topographically perched relative to the local ground water, e.g., in
topographic saddles, near places of rapid topographic drop-off or
cliffs. This requires that an effective \"seal\" of clay or organic
matter keep the lake from draining faster than it can be recharged by
inflow. In such systems, the local groundwater table is lower than the
lake surface or the groundwater level is about the same elevation as
that of the lake surface, thus providing little or no pressure
difference to cause ground water to flow into the lake. Instead, the
lake normally drains to ground water or there is insignificant
contribution by ground water to the lake.

The discussion above centers around weathering products, which are
important in determining sensitivity of lakes and streams to atmospheric
deposition and some other sources of acid. Some types of bedrock, e.g.
limestone and other sedimentary rocks with significant amounts of
carbonate, weather readily and provide great protection against acid
deposition. Other types of bedrock, e.g., granite and quartzite, weather
slowly and often underlie areas that contain sensitive lakes and
streams. Such systems also may be very sensitive to other inputs, such
as nutrients from atmospheric deposition or land use disturbance.

# PROTOCOL REQUIREMENTS

## Bottles

The bottles required for samples vary with the constituents to be
sampled and the laboratory doing the analysis. Sometimes, several
bottles will be required for each sample, with differing processing of
each bottle required in the field or at the laboratory. The bottles used
need to be non-reactive with the constituents measured from that bottle.
Most constituents are collected in polyethylene bottles, but organic
constituents such as pesticides typically are collected in glass
bottles. The sample must be large enough for the laboratory to do any
needed processing and analysis and have sufficient excess if a rerun of
the archived sample is needed. Each bottle must have a waterproof label
and all the information required by the laboratory must be written with
waterproof ink. Because the needs of the laboratory must be considered
it is advisable to obtain all bottles from the laboratory doing the
analyses. The laboratory also may be able to supply appropriate labels
with pre-printed data fields showing what information is required.

To minimize contamination of the sample by impurities in the bottle
itself polyethylene bottles should be rinsed three times with deionized
water, filled with deionized water, and allowed to stand for at least 48
hours. This service may be provided by the laboratory supplying the
bottles. Bottles should be carried to the sampling site filled with
deionized water from the laboratory. The deionized water then is
emptied, in a manner so as not to mix the deionized water with the water
to be sampled, immediately prior to sampling and the bottle and cap
rinsed three times with sample. Then the sample is collected and the
bottle capped. At all stages of sampling care should be taken not to
contaminate the inside of the bottle or cap with fingerprints or soil
and other impurities. Powder-free gloves should be worn to minimize
contamination by the sampler's arm as the sample is collected. It
requires only very small amounts of solids such as soil to overwhelm the
chemistry of the water sample itself. For the analysis of trace metals
acid cleaning of the polyethylene bottles is required; the laboratory
providing the bottles should do this. These bottles and their caps are
rinsed three times with sample before collecting the sample.

Glass bottles used for organic analyses often are cleaned by heating in
a furnace to burn off all traces of organic materials. These glass
bottles do not need to contain deionized water nor do they require
rinsing with sample before sample collection.

To assure that the bottles used are not contaminating the sample it is
necessary to analyze samples of \"blank\" water that have been stored in
the bottles for time periods comparable to the amount of time sample
remains in the bottle before analysis. This is most conveniently done on
each batch of bottles obtained from the manufacturer. Thus, it is most
efficient if the laboratory supplying the bottles perform this quality
assurance test. It is necessary to know the composition of the deionized
water prior to being stored in the bottles and then analyze samples
after storage in the bottles. The stored water should show constituents
below the detection limit. If significant concentrations are found the
batch may need to be rejected or the bottles may need additional
cleaning.

Bottles need to be protected from contamination during transport to and
from the sampling site. It is most convenient to keep the complete set
of pre-labeled bottles for each site together in a sealed plastic bag.
This minimizes the chance for dust to accumulate on the bottle and
potentially contaminate the sample, as well as making all the required
bottles readily available. If one or more bottles have some remaining
acid from cleaning, such bottles should be packed separately to minimize
the potential for cross contamination, e.g., of nutrient samples by
nitric acid washed bottles.

Bottles need to be protected from excessive heat to minimize degradation
of the sample. Excessive cold can freeze samples, which may rupture
bottles or irreversibly precipitate out some constituents. Sunlight not
only can heat the sample, but also encourage the growth of
phytoplankton. The bottles filled with sample should be stored in the
dark and just a few degrees above freezing. Thus, packing them with ice,
cold packs, or snow if it is handy, in an insulated cooler is best. Dry
ice should not be used because it could freeze the sample. If an
extended period without cooling is the only feasible option, filtration
of the samples at the site of collection and addition of preservatives
such as nitric acid to some aliquots should be used to protect the
integrity of the sample.

## Filters

Many samples require filtration either in the field or the laboratory.
This filtration separates constituents dissolved in the water from
detritus and other solids that may alter the chemistry of the sample
before it can be analyzed. Filtration in the field adds the possibility
of sample contamination if not done carefully. Program needs and the
nature of the water being sampled determine whether the greater risk is
from field filtration or from sample degradation before filtration at
the laboratory. Samples containing large amounts of suspended solids or
organic matter and samples analyzed for trace constituents (such as
dissolved iron) are the most susceptible to degradation before
filtration at the laboratory. If samples are filtered in the field, it
is possible to check for contamination by processing (filtering)
deionized water of known composition at the same time to determine
whether field filtration is associated with contamination.

As with bottles, each batch of filters must be checked to assure that
they do not contaminate the samples. For the same reasons discussed for
bottles, it is most efficient if the laboratory supply and quality
assure any filters that are used for field filtration. As with bottles,
care should be taken to avoid contamination of the filter and filter
apparatus from fingerprints and soil. The filter and apparatus need to
be rinsed well with either deionized water or sample prior to filling
the sample bottles. Because filtering apparatus varies greatly in size,
it is impossible to give universal guidelines on the amount of rinse
needed. Thus, it is most efficient if the laboratory specifies or
provides any filtering apparatus and determines an appropriate rinse
protocol for that apparatus. Filters commonly used are made of
polycarbonate or are cellulose-based, e.g., cellulose acetate. The pore
size of the filter is critical in determining what actually is analyzed
in filtered samples. A pore size of 0.45 microns is commonly used for
many constituents, .1 microns is used for many metals such as aluminum;
however, smaller pore sizes may be needed for the analysis of some trace
metals if colloidal material is present in significant amounts. This is
best determined by comparing a series of aliquots collected with filters
of differing pore sizes, for example, 0.4 and 0.1 micron filters. This
needs to be done only in studies that need the best estimates of
dissolved trace metal concentrations.

## 

**Standard Surface Water Constituents**

Constituents to be determined are best considered as packages or
analytical suites. The most basic suite includes all those constituents
that have the greatest concentrations and that together exert many
chemical controls on the nature of the water. This core group is called
the major ions and common field measurements and includes:

1\) Major cations - H+ (from pH), Ca+2, Mg+2, K+, Na+, NH4+. H^+^ and pH
are important because of direct toxicity to aquatic organisms and they
affect the solubility of toxic metals. The ions Ca+2, Mg+2, K+, Na+ are
important indicators of how the rock and soil in the watershed react
with water.

2\) Major anions -- Acid neutralizing capacity (ANC), SO4-2, NO3-, Cl-.
ANC is an important measure of the lake or stream's ability to
neutralize acid; if it is concentration is near zero then additional
acid can easily affect pH and produce toxic conditions. The ions SO4-2
and NO3- are common indicators of acid from manmade or natural sources.
Cl- is very useful in estimating the amount of evapo-transpiration in
some watersheds.

3\) Common field measurements -

Water temperature, pH, and specific conductance

Dissolved oxygen

Secchi disk depth (if sampling from a boat) in a lake

Water level and, if applicable, discharge

**Additional Surface Water Constituents**

Depending on the stated program objectives, many additional constituents
can be added to the major ion/common field measurement suite. Common
additions are:

1\) Additional nutrients - total P, soluble reactive P, total N.
Nutrients are important in studies involved with the productivity of
fisheries and with oxygen depletion. Point sources of nutrients, such as
sewage outfalls, and non-point sources, such as intensive grazing near
waterways, can greatly affect water chemistry, algal productivity, and
the viability of aquatic organisms.

2\) Additional inorganic chemistry - dissolved Al, large suites of other
dissolved trace metals. Increased solubility of trace metals at low pH
can cause toxic concentrations. Low pH commonly is a result of acid
precipitation in watersheds of unreactive geology or of acid mine
drainage.

3\) Organic chemistry - Total organic carbon (TOC), dissolved organic
carbon (DOC), various suites of pesticides and other organic toxins. TOC
and DOC affect the toxicity of some trace metals, such as Al. Pesticides
and organic toxins may be deposited by atmospheric deposition or runoff
from treated lands.

4\) Basic aquatic biology - phytoplankton, zooplankton,
macroinvertebrates, fishery. Each type of organism interacts with water
chemistry and may be an indicator of adverse chemistry not initially
detected by sampling only chemistry. These organisms frequently are
considered AQRVs or to have economic importance, such as fisheries.

5\) Bacteria - total and fecal coliform, fecal strep. These organisms
are used as indicators of contamination from sewage, grazing, or general
soil contamination.

## Selection of Sampling Site

The sampling site needs to be safe, accessible, easily located by others
using field descriptions, and representative of that part of the lake or
stream of interest. In both lakes and streams the site should have good
hydrologic connection with the main mass of water, i.e., circulation
should not be impeded by excessive vegetation, shallow water depth, or
be in a restricted embayment. The presence of tributaries needs to be
considered so that adequate mixing is assured if sampling downstream of
a tributary. Some measurement of specific conductance across a stream or
in the vicinity of a lake inflow can determine whether mixing is
complete.

If possible, lakes should be sampled away from shore by boat. If
otherwise suitable, the deepest part of the lake is preferable. After
determining the sampling location it should be marked with a permanent
buoy, coordinates determined by GPS, or triangulated from easily
recognized landmarks and these should be noted in any instructions to
future sampling teams. If sampling by boat is not feasible then a shore
location such as a rocky point located on the main body of the lake may
be suitable. Lake outflows also may be suitable for sampling if the lake
normally has significant discharge; otherwise, the outflow may not have
good circulation with the lake.

Sampling locations in streams, including inflows and outflows of lakes,
should be in areas of significant flow and little possible effect from
tributaries, stagnant flow areas, or point sources and structures that
may introduce their own chemistry. If safe, the sampler should wade to
mid-stream in a well-mixed section of small streams. If available, a
bridge or a boat can provide access to mid-stream areas of larger
streams. If it is unsafe or not practical to sample at mid-stream then
an area of unrestricted flow that can be sampled from shore should be
used.

##  

## Observations

In addition to field measurements, described below, the person sampling
should note a variety of things that can be observed. For example, are
insects, fish or amphibians observed? If so, information on approximate
numbers, size, and type might be valuable later in determining whether
changes have occurred in the biotic community. Certainly, any
observation of dead biota should be noted, as this may indicate recent
harmful changes in chemistry or physical conditions such as lack of
oxygen, toxic agents, etc. Indications of recent high stage flow should
be indicated. Land use and disturbances such as camps, livestock, and
evidence of recent timber harvest or mining need to be recorded.
Photographs of the sampling site, lake, and watershed provide valuable
information in understanding the system.

## 

## Weather

## Weather can affect surface water chemistry. Wind and the amount of solar radiation are very important to the stratification of water and chemistry in lakes. Rain and snowmelt are important to the chemistry of streams. Air temperature and atmospheric pressure can indicate whether conditions are stable or a storm has recently occurred or is about to develop. It takes only a few minutes to record basic conditions, i.e., Percent cloud cover, approximate wind speed and direction, whether storms are or have recently occurred, the status of snowmelt (if applicable), air temperature, and atmospheric pressure.

## Dissolved Oxygen Measurement

Dissolved oxygen (D.O.) can only be measured in the field. It is an
important measurement because there are minimum D.O. requirements for
aquatic vertebrates such as fish and amphibians, and the presence or
absence of D.O. is a major influence on the solubility of constituents
such as trace metals. Dissolved oxygen can be added to the water from
the atmosphere or from photosynthesis by phytoplankton, macrophytes, and
periphyton. Dissolved oxygen can be removed from the water to the
atmosphere or by respiration and by decay processes in the water or the
sediments. The ability of the water to contain D.O. is determined by its
temperature, salinity, and the atmospheric pressure, with the solubility
of D.O. decreasing with increasing temperature, increasing salinity, and
with decreasing atmospheric pressure. Tables of solubility as a function
of these variables are available (Wilde and others, 1998-1999). In
lakes, the D.O. normally differs from the surface to the bottom and
profiles of D.O. are done if samples are collected from a boat.

##  

## Water Temperature Measurement

Water temperature can only be measured in the field. Water temperature
is important as a measure of habitat conditions for organisms and is an
excellent index to compare samples among different years. Because of
annual differences in weather, the water temperature often is a better
indicator of the annual hydrologic cycle than is the calendar date.
Water temperature should be measured at all sites when collecting water
samples. Either thermometers or thermistors may be used; either must be
calibrated at two temperatures.

### 

### **pH** 

The pH of water, especially in very dilute systems, can be difficult to
determine accurately unless sampling personnel are carefully trained.
Thus, pH of samples collected during initial inventories may be better
measured in the laboratory. Because the pH can change between collection
and analysis in the laboratory it is useful to have trained personnel
make at least some field measurements for comparison to verify that the
laboratory measurements differ little from field values. Both
measurements are useful and at least one of the two is necessary. The pH
is an important control on solubility of many trace elements and also
may have biological effects itself. The meter must be digital and
capable of reading to the nearest 0.01 pH unit. Other types of pH
monitors are not acceptable because there is a high likelihood of
erroneous measurement. The electrode typically is a combination
(reference and pH indicating electrodes together) and should be suitable
for measuring even low ionic-strength water. Calibration requires the
use of two buffers that bracket the expected pH, commonly 4.00 and 7.00
buffers. Some electrodes that calibrate well with buffers, which are
very concentrated solutions, fail to accurately measure pH in dilute
water. The dilute acid standard used for National Acid Deposition
Program (NADP) calibration can be used to verify the proper function of
the electrode.

**Specific Conductance**

The specific conductance can be measured at the laboratory but at least
some field measurements should be taken for comparison (particularly for
inventory sampling) to verify that the laboratory measurements differ
little from field values. Specific conductance is critical in quality
assuring most major ion analyses. Specific conductance often is so
highly correlated with each major ion\'s concentration that it can be
used cost effectively to approximate those concentrations in between
actual analyses. Because of these uses and because of the simplicity of
the measurement it should be measured on all samples.

## Secchi Disk Depth

The Secchi Disk depth measurement is performed from a boat in water deep
enough to exceed the visibility limitations of the water. The disks come
in differing sizes and may be black and white, all white, or mirror
finish. Measurements are subject to individual eyesight problems, glare
on the water, waves, etc. so notes on who is measuring and how are
important. For consistency, it is best to measure on the shady side of
the boat to minimize glare and to not wear sunglasses. A calibrated
chain is attached to the disk and the disk lowered until it disappears,
and the depth recorded. The disk is slowly raised until it reappears and
that depth recorded. The average of the two depths is the single value
normally entered as the Secchi Disk depth. If the disk can be lowered to
the bottom and still be visible this should be noted, e.g., \"Secchi
Disk depth greater than maximum depth.\"

## Water Level and Discharge

Surface water chemistry can change in response to changes in the inflow
of water, on timescales from less than a day to over an entire season.
In lakes the water level can be a convenient measure of whether the
sample is being collected during a period of generally normal, dry or
wet conditions. The water level can be measured and continuously
recorded by instruments that monitor a float assembly or pressure
transducer, or just when samples are collected. It is important that a
constant reference elevation is available so that all measurements are
relative to the same reference; this could be a permanently mounted
staff gage (a weatherproof \"yardstick\" used especially for this
purpose) or a spike or other convenient point from which a metal tape
can be dropped to the water surface.

# SAMPLE HANDLING

Sample collection removes the sample from an environment operating at
approximately steady state. The counteracting physical and biological
influences that maintain surfacewater chemistry fairly constant from
day-to-day no longer are in balance within the sample bottle. There are
rapid changes in temperature and, perhaps, dissolved oxygen
concentration. Without sunlight, algae cease to grow whereas zooplankton
continue to eat algae and to excrete. Bacteria may thrive on dead algae
and the zooplankton excretions. Thus, nutrient concentrations may
rapidly change. Trace metals may move from the dissolved state to being
adsorbed to bottle walls or being taken up by bacteria. Regarding how
rapidly the chemistry may change the sample can be thought of as a
dilute soup; the same changes that can cause such a soup to spoil happen
to water samples and at comparable rates. The sampler should arrange to
have samples analyzed before this \"spoilage\" can occur.

Immediate analysis is impractical in most field situations except for
the common field measurements, such as water temperature, pH, specific
conductance, and dissolved oxygen. Chilling immediately after collection
to a few degrees above freezing and rapid shipment to the laboratory are
the most effective approach if field processing, such as filtering and
the addition of preservatives, is impractical. The samples must not
freeze because this can break the bottle or cause irreversible
precipitation of some constituents, such as dissolved orthophosphate.
Holding times before analysis vary among constituents. Morrison (1991)
lists holding times between 48 hours (color) and 6 months (major cations
and Al). For constituents needed by many programs, 7 days is a practical
limit (nitrate and laboratory pH) as long at the samples are kept
chilled until analysis is conducted.

# DATA QUALITY ASSURANCE

## Long Term Monitoring Samples

## Quality assurance of data is greatly facilitated if a site has been sampled many times before. At a site, fairly stable relationships among constituents and with variables such as discharge and season exist and can be used to decide whether new data are suspect. At each site, some relationships will be more reliable than others and the quality assurance should be tailored to what works at that site. Suspect data require that the sample be rerun analytically and/or the data flagged in the database.

## Synoptic (Inventory) Samples 

Although synoptic samples may have few or no historic samples to use for
quality assurance, it may be possible to do similar stepwise quality
assurance of each analysis. Samples from lakes or streams draining
terrain similar in geology, elevation, vegetation, etc. may be combined
in the plots described above and one or more clusters of relationships
may be apparent. These can be used to determine which constituent likely
is in error; although, the apparent outliers are more subject to real
differences among the sites.

## Cross Comparison and Sample Archive

In any sampling program, historical data will sometimes be questioned
for accuracy. Changes in methodology for sampling and analysis can cause
systematic differences in the data that complicate detection of trends.
Before any change in methodology is adopted, it is important to collect
and analyze duplicate samples by the old and new methods. A sufficient
number of comparisons to cover the normal range of values and to provide
a valid statistical comparison are needed.

Even when care is used in adopting changes in methodology, questions can
develop as to the validity of older data or it may be desired to analyze
for constituents not originally determined. Archived samples often can
determine whether the older data are valid or to expand the constituents
determined as new project needs develop. Archives representing the range
of values for chemistry can be collected as duplicate samples to be used
only for archive purposes or remaining portions of routine samples can
be used. Although archive samples necessarily violate holding time
requirements for routine samples many constituents may be effectively
preserved for an indefinite period. Changes can be minimized by
techniques including:

1\) Filtering the sample.

2\) Minimizing headspace in the bottle.

3\) Keeping the samples chilled and in the dark.

Because archived samples require a commitment of time, space, and
attention it is desirable and efficient to have a centralized sample
archive. A more limited local archive also can be maintained.

## Responsibility for QA

Basic quality assurance of data, as discussed above, can be done locally
by the office collecting the samples and/or centrally; also, it can be
done internally or contracted. Depending upon the expertise and time
available it can be done well, poorly, or not at all in any of these
choices. The most important decision to make in planning for quality
assurance is to assure that someone qualified does it and does it soon
after samples have been analyzed. It is almost useless to determine that
data are suspect only after the laboratory has discarded the samples; at
best, the data only can be deleted or flagged in the data base. To
assure that the quality assurance plan is adequate there should be a
formal report submitted of what has been done to quality assure data and
what is planned for future data. It is critical that whoever reviews and
approves the quality assurance report have the proper background and
commitment to provide a critical review. Because data may be used for
interpretation or in litigation, either immediately or much later after
all project personnel have changed, the reports should be archived.
Preferably, the reports should be available for review from the same
data administrators who provide the data for public or internal use.
Occasional review of the quality assurance process by qualified
professionals from outside the agency can help assure that generally
accepted approaches are used.

**^(1)^**Excerpted from Turk, J.T. 2001. *Field Guide for Surface Water
Sample and Data Collection*. Report prepared for the Air Program,
U.S.D.A. Forest Service. 67p.

(for complete publication or additional information, contact Tamara
Blett at (303) 969-2011 or <Tamara_Blett@nps.gov>

**APPENDIX C**

**Protocol for Identifying Ozone Injury on Eastern Forest Plants^(1)^**

###### Steps for Diagnosing Ozone Injury on Selected Eastern Forest Bioindicator Plants

1\. Look for ozone injury during the mid to late summer. In the East,
the best time to observe injury is between mid-July and mid-September.
At higher elevations, however, ozone injury may be masked by early fall
coloration.

2\. Find an opening with full sunlight exposure. Good places to look for
ozone injury on bioindicator plants are openings away from major paved
roads and power lines. Examples of openings include clearings for
wildlife, old meadows, and recently harvested areas. The bioindicator
plants to look for include blackberry (second-year canes), black cherry,
common milkweed, green ash, yellow-poplar, and white ash.

3\. Select areas with no obvious conditions that would cause mimicking
symptoms of ozone injury. Examples include herbicide applications and
mechanical or physical damage. Determine the presence of herbicide or
other damaging agent if many plant species in the area (in addition to
bioindicator plants) show the same symptoms. These types of areas should
be avoided during surveys.

4\. Look for symptoms on mature leaves that are in full sunlight. The
leaves must be exposed to the sun to reveal injury. Symptoms should
appear over most of the plant that is in full sunlight, rather than on
just one or two branches or leaves. It is easiest to examine plants for
which at least 25 percent of the foliage is within your reach.

The typical symptom of ozone is an upper leaf surface interveinal
stipple. Stipple is the discoloration of small groups of cells between
the veins, appearing as uniformly sized red to brown spots.

The ozone injury pattern normally does not go through to the underside
of the leaf. If the injury pattern carries through to the underside,
then the injury on the upper surface is probably caused by something
other than ozone, such as insects, disease, or weather-related factors.

Older leaves show injury. Look for injury on the more mature foliage.
There should be an increase in severity of injury from the youngest to
the oldest leaves. Sometimes, young leaves look sunburned and have an
overall red appearance. This is not due to ozone.

Shaded portions of overlapped leaves do not show visible ozone injury.
If you move a leaf with ozone injury that is overlapping another leaf
with injury, you should see no injury on the lower leaf where the top
leaf covered it.

Leaves may show signs of premature aging. Some plants respond to ozone
by dropping their injured leaves. Check on the ground beneath the plant
to confirm if there is ozone injury on the fallen leaves.

5\. Does the bioindicator plant you are evaluating fit these criteria?
Have your considered site factors and other agents that can cause
mimicking symptoms? If so, you may feel confident that you are observing
ozone injury!

**List of selected eastern forest bioindicator plants and most common
visible symptoms of ozone injury:**

Blackberry, secondary canes (*Rubus spp.*): Red to purple stipple.

Black cherry (*Prunus serotina*): Red to purple stipple, may drop the
injured leaves early.

Common milkweed (*Asclepias syriaca*): Purple to black stipple, leaves
may be chlorotic (yellow).

Yellow-poplar (*Liriodendron tulipifera*): Brown stipple, may drop the
injured leaves early.

White ash (*Fraxinus americana*): Red to brown stipple. Similar injury
is also found on green ash.

####### **Quantifying Ozone Injury on Plants**

There are a number of ways to assess ozone injury on bioindicator
plants. One method is to document the presence or absence on a
predetermined number of plants in a given area. Another method is to
quantify the amount and severity of injury that is present on leaves or
plants. Amount and severity of injury are generally evaluated on a
percent scale to obtain precise estimates of ozone injury. Changes in
the ratio of injured to uninjured plants or in the amount and severity
of injury can provide an indication of changes in air quality and injury
conditions for a given area.

###### Reference

Skelly, John M.; Davis, D.D.; Merrill, W.; Cameron E.A.; Brown, H.D.;
Drummond, D.B.; Dochinger, L.S.; eds. 1987. *Diagnosing injury to
eastern forest trees: a manual for identifying damage caused by air
pollution, pathogens, insects, and abiotic stresses.* National Acid
Precipitation Assessment Program, Forest Response Program, Vegetation
Survey Research Cooperative. University Park, PA: Agricultural
Information Services, College of Agriculture, Department of Plant
Pathology, Pennsylvania State University. 122 p.

**^(1)^** excerpted from Brantley, E.A., R.L. Anderson, and G. Smith.
*How to Identify Ozone Injury on Eastern Forest Bioindicator Plants*.
U.S.D.A. Forest Service. Southern Region. Forest Health Program.
Asheville, NC.

(for complete publication, see
http://fhpr8.srs.fs.fed.us/pubs/ozone/r8-pr25/ozoneh2.htm)

**APPENDIX D**

**Protocol for Identifying Ozone Injury on Western Pines^(1)^**

Tree‑level data should be collected by evaluating the crown and bole
condition of each tree including whole crown, branch variables, and
whorl variables. These evaluations are performed by visual estimates and
by using simple instruments, both on the whole tree and on branch
samples extracted from the lower crown. The approved methods for
measuring DBH, selecting the category of slope position, and category of
microrelief should become familiar to the field crew (Zedaker and
Nicholas 1990).

Whole tree and crown evaluations may be recorded on a data sheet.
Instructions are provided for judging the crown position, measuring tree
height, and rating the severity of dwarf mistletoe infection. A visual
estimate should be used to record further tree injury observations using
these classes: 0=none;1=present; 2=severe for the following: conks
(identify species if possible); bark beetles (identify species if
possible); witches brooms (with or without presence of dwarf mistletoe
plants); fire scars (the rating refers to the percent of the
circumference affected); mechanical injury (specify type); and lightning
scars.

However, factors that may confound the evaluation of chlorotic mottle
and needle retention that occur on specific branches should be avoided
if they are not present on the majority of all branches in the lower
crown. Branches with dead terminal buds, severe needle cast fungi,
severe scale infestations, or that have obviously been severely chewed
by insects or squirrels should therefore be rejected. Branches with
cones or those which bifurcate (split) within the foliated length should
be accepted, although their evaluation may be more time‑consuming.
\"Branchlets\" (the smallest side branch with a full complement of
needle whorls) should be cut from near the crown edge without pruning
the branch leader of major branches; the middle of the lower crown
should be sampled on all sides of the tree. The very lowest branch on
mature trees should be avoided because it may soon die as the tree
self‑prunes with age; its overall vigor is probably less than the rest
of the lower crown. Small trees should not be over‑pruned.

Five branchlet measurements are required for adequate within‑tree
replication:

• Foliated length‑The length of the woody stem should be measured from
the base node of the oldest whorl with green foliage (even if younger
whorls are missing) to the base of the terminal bud. This is a general
measure of overall vigor of the tree and potential growth rate.

• Number of whorls‑The whorls of needles retained should be counted.
This is a measure of the age of the oldest foliage retained on the
branch in years minus one. If a whorl is missing between older and
younger foliage, it is tallied on the data sheet as a \"0\". Whorls with
short needles must also be included.

• Chlorotic mottle‑The severity of chlorotic mottle resulting from ozone
injury should be estimated as a visual estimate of the surface area of
each whorl covered with mottle using the following classes:

> 0 = no mottle observed
>
> 1 = 1‑6 pct
>
> 2 = 7‑25 pct
>
> 3 = 26‑50 pct
>
> 4 = 51‑75 pct
>
> 5=\>75pct.

• Fascicle retention in whorls‑The portion of the full complement of
needle fascicles that remain, should be estimated by using the following
classes:

> 1 = 1‑33 pct
>
> 2 = 34‑66 pct
>
> 3 = 67‑100 pct

To estimate fascicle retention, abscission scars (small pits in the
scaly branch surface) should be noted between the whorl nodes. Most
often on younger needle whorls none will be present, and the retention
class will be 3 (100 pct). It is not necessary to actually count all
abscission scars and retained fascicles; a visual estimate is
sufficient.

• Common needle length‑The common needle length in each whorl should be
measured with a ruler to the nearest centimeter in the center portion of
the whorl. The needle tips should not be chewed off at the same point by
insects, but if they have been, a \"missing\" data value should be
recorded or another branch selected.

^**(1)**^ excerpted from Miller, P.R., K.W. Stolte, D.M. Duriscoe, and
J. Pronos, technical coordinators. 1996. *Evaluating Ozone Air Pollution
Effects on Pines in the Western United States*. General Technical Report
PSW-GTR-155. Pacific Southwest Research Station. Forest Service. U.S.
Department of Agriculture. Albany, CA. 79p.

######