Fire ecology of forests and woodlands in Utah

138 Pages·1992·12.6 MB·English

by  Bradley, Anne F

Historic, Archive Document
Do assume
not content reflects current
scientific l<nowleclge, policies, or practices.

United States Fire Ecology of Forests
Department
of Agriculture
and Woodlands
Forest Service Utah
in
Intermountain
Research Station
General Technical Anne Bradley
F.
Report INT-287
Nonan Noste
V.
June 1992
William C. Fischer
CP . \
-«
^3
THE AUTHOF
United States
Department of
Agriculture Page
ANNE BRADI
F.
1
specialist forthe
1
Staff of the Fore!
6
in San Francisco
r Tree Species to Fire 6
occurred while a; pulus tremuloides) 6
Effects: Prescrib
'nus ponderosa) 7
unit at the Internr
otsuga menziesii) 7
tain Fire Science
{Picea engelmannii) 8
earned a B.A. de
nus contorta) 8
and an M.A. deg
s lasiocarpa) 8
Montana. Early National Agricultural Library
ncoloi) 9
naturalist for the
\pungens) 9
biological techni(
e {Pinus longaeva) 9
Intermountain St_
^'giiriugrrnrciFTTTpg flexilis) 10
NONAN V. NOSTE (retired) was a forester, Inter- Gambel Oak {Quercusgambelii) 10
mountain Research Station, Intermountain Fire Pinyon {Pinus edulis) and Singleleaf Pinyon
Sciences Laboratory, Missoula, MT. During his Forest Pinus monophylla) 10
(
Service career, Nonan was involved in fire control Utah Juniper {Juniperus osteosperma) 11
research in Alaska; silviculture research in Wisconsin, Rocky Mountain Juniper
and fire technology and fire effects and use research {Juniperus scopulorum) 11
in Missoula. He earned B.S. and M.F. degrees in Undergrowth Response to Fire 11
forestry from the University of Montana. Wildlife Response to Fire 18
WILLIAM C. FISCHER is a research forester and Fire Use Considerations 30
Fuels 30
team leader for the Fire Effects work unit at the
Predicting Fire Mortality 32
Intermountain Research Station, Intermountain Fire
Crown Damage and Insect Attack 34
Sciences Laboratory, Missoula, MT. He is a graduate
Frequency of Burning 34
of Paul Smith's College and the University of Michigan
Large Woody Debris 34
(B.S., B.S.F. 1956). Priorto joining the staff at the Fire
Sciences Laboratory, he was employed in a variety of Heat Effects on Soil 35
fire and resource management assignments with the Prescribed Fire Planning 35
Fire Group Zero: Miscellaneous Special Habitats ....35
Boise National Forest in Idaho.
Scree 35
Forested Rock 35
RESEARCH SUMMARY
Wet Meadow 35
Mountain Grassland 36
This report summarizes available information on fire
Deciduous Riparian Communities 36
as an ecological factor for forest habitat types and the
unclassified pinyon-juniper and oak-maple woodlands Fire Group One: Pinyon-Juniper Woodlands 36
Vegetation 36
occurring in Utah. Habitat types and the unclassified
Forest Fuels 37
vegetative communities are assigned to Fire Groups
based on fire's potential role in forest succession. Role of Fire 38
Woodland Succession 39
For each Fire Group, the authors discuss (1) the
relationships of major tree species to fire, (2) forest Fire Management Considerations 41
Fire Group Two: Montane Maple-Oak Woodlands...41
fuels, (3) the natural role of fire, (4) fire's hypothetical
role in forest succession, and (5) fire management Vegetation 41
Fuels 42
considerations.
intermountain Research Station
324 25th Street
Ogden, UT 84401
Page Page
Role of Fire 43 Fire Group Eight: Habitat Types with
Brushland Succession 44 Persistent Lodgepole Pine 79
Fire Management Considerations 44 Habitat Types, Phases 79
Fire Group Three: Ponderosa Pine Habitat Types ...45 Vegetation 79
Habitat Type, Phase 45 Forest Fuels 79
Vegetation 46 Role of Fire 82
Forest Fuels 47 Forest Succession 85
Role of Fire 48 Fire Management Considerations 87
Forest Succession 49 Fire Group Nine: Climax Stands Dominated by
Fire Management Considerations 52 Limber Pine or Western Bristlecone 89
Fire Group Four: Drier Douglas-fir Habitat Types ....54 Habitat Types, Phases 89
Habitat Types, Phases 54 Vegetation 89
Vegetation 54 Forest Fuels 90
Forest Fuels 54 Role of Fire 90
Role of Fire 55 Forest Succession 91
Forest Succession 56 Fire Management Considerations 91
Fire Management Considerations 58 Fire Group Ten: Dry, Lower Subalpine
Fire Group Five: Cool or Moist Douglas-fir Habitat Types 92
Habitat Types 59 Habitat Types, Phases 92
Habitat Types, Phases 59 Vegetation 93
Vegetation 59 Forest Fuels 93
Forest Fuels 59 Role of Fire 94
Role of Fire 59 Forest Succession 94
Forest Succession 61 Fire Management Considerations 99
Fire Management Considerations 64 Fire Group Eleven: Moist to Wet Subalpine
Fire Group Six: White Fir and Blue Spruce Habitat Types 99
Habitat Types (Mixed Conifer Types) 64 Habitat or Community Types 99
Habitat Types, Phases 64 Vegetation 99
Vegetation 64 Forest Fuels 100
Forest Fuels 66 Role of Fire 100
Role of Fire 67 Forest Succession 101
Forest Succession 67 Fire Management Considerations 101
Fire Management Considerations 69 Fire Group Twelve: Cold, Upper Subalpine
Fire Group Seven: Aspen-Dominated Habitat Habitat Types 102
and Community Types 70 Habitat Types, Phases 102
Stable Community Types (Probably Vegetation 102
Climax Habitat Types) 70 Forest Fuels 102
Community Types (and Cover Types) Role of Fire 102
Probably Serai to Coniferous Habitat Types 70 Forest Succession 103
Community Types Probably Grazing Fire Management Considerations 104
Disclimaxes 71 References 104
Vegetation 71 Appendix A: Forest and Woodland Habitat
Forest Fuels 71 and Community Types Assigned to
Role of Fire 72 Utah Fire Groups 120
Forest Succession 74 Appendix B: Common and Scientific
Fire Management Considerations 75 Names Mentioned in Text 125

—
Fire Ecology of Forests and
Woodlands Utah
In
Anne F. Bradley
Nonan V. Noste
William C. Fischer
INTRODUCTION
major topics presented in this report are organized
into sections, described below.
This report summarizes the available fire ecology
and management information relating to forest Relationship ofMajor Tree Species to Fire
habitat types, montane oak-maple woodlands, and This section discusses each principal tree species in
pinyon-juniper woodlands ofUtah. Specifically, the Utah forests with regard to its resistance or suscep-
report covers the Wasatch-Cache, Dixie, Fishlake, tibility to fire and its role as a successional compo-
Manti-La Sal, Ashley, and Uinta National Forests nent offorest communities. Particular attention is
and the Raft River Mountain portion ofthe Sawtooth given to special adaptations to fire, such as corky
bark, serotinous cones, or seeds that require mineral
National Forest, but it is also applicable to the for-
ested portions ofZion and Bryce Canyon National soil for germination.
—
Parks and Cedar Breaks National Monument. The Undergrowth Response to Fire This section
primary purpose ofthis report is to promote the un- summarizes the effect offire on the response ofim-
derstanding offire's role, particularly its influence portant grass, forb, and shrub species associated
on succession in the forests, pinyon-juniper wood- with the major conifer species. Particular attention
lands, and oak-maple brushlands ofUtah, is given to fire-adaptive traits or survival strategies
The habitat types recently described by Mauk that determine whether fire generally increases or
and Henderson (1984), Youngblood and Mauk decreases species cover in the immediate postfire
(1985), and to a limited extent the community types period.
described by Padgett and others (1989) and by —
Wildlife Response to Fire This section con-
Mueggler (1989) are assigned to 13 "Fire Groups"
tains briefsummaries ofthe general effects offire on
based on the response ofdominant tree species to
common Utah mammals, reptiles, amphibians, and
fire and similarity ofdevelopment in postfire succes-
birds. Fire response ofwildlife is largely inferred
sion. In Utah, neither pinyon-juniper woodlands nor
from expected changes in habitat as a result offire.
montane woodlands dominated by Gambel oak or
—
bigtooth maple have been classified by habitat type. Fire Use Considerations This section summa-
These woodlands therefore have been assigned to rizes cautions that apply to the use offire for re-
Fire Groups on the basis ofcover type. Both pinyon- source management purposes. Emphasis is on effec-
juniper and oak-maple cover large acreages in the tive use offire, site protection, minimizing damage
State. to residual stand, and wildlife habitat protection.
The successional path taken by any given site fol- Fire Groups—The Fire Groups (FG's) are defined
lowing fire depends on many variables. The preburn with reference to "Coniferous Forest Habitat Types
vegetation, size and severity ofthe fire, topography, ofNorthern Utah" (Mauk and Henderson 1984), "Co-
climate and soil, and chance all contribute to the niferous Forest HabitatTypes ofCentral and South-
process. Thus, a single habitat type may be a mem- em Utah" (Youngblood and Mauk 1985), "Aspen
ber ofmore than one Fire Group. The individual Community Types ofthe Intermountain Region"
land manager must evaluate conditions on a site by (Mueggler 1989), and "Riparian Community Types
site basis to determine the most likely results offire. ofUtah and Southeastern Idaho" (Padgett and oth-
The groups defined in this report are offered as a
ers 1989). Generally, a habitat type or habitat type
general guide, not a definitive treatment. phase is assigned to only one Fire Group. Where
exceptions to this rule occur, the exception is noted
Format and explained. The foresthabitat types assigned to
the Utah Fire Groups are listed in appendix A and
This report is patterned after "Fire Ecology of summarized in table 1. General descriptive litera-
Montana Forest Habitat Types East ofthe Conti-
ture was used to identify pinyon-juniper woodlands
nental Divide" (Fischer and Clayton 1983). The
(FG 1) and oak-maple woodlands (FG 2), because
1
—
Table 1 Summary of Utah habitat type Fire Groups (see appendix A forformal listing of habitattypes)
Habitat type Habitat type Habitat type
FIRE GROUP ZERO PIPU/BERE PICOA/ASC
Misc. special habitats PIPU/JUCO PIENA/AGA
PIENA/ASC
FIRE GROUP ONE FIRE GROUP SEVEN
Pinyon-juniper woodlands POTR/AMAI_/PTAQ FIRE GROUP NINE
FIRE GROUP TWO POTR/AMAI_/TALL FORB PIFL/BERE
POTR/AMAI7THFE PIFUCELE
Montane maple-oak
POTR/AMAUCARU
FIRE GROUP TEN
FIRE GROUP THREE POTR/AMAL-SYORATALL FORB
ABLA/ACGL
PIPO/ARPA POTR/ARTR
ABLA/BERE-CAGE
PIPO/ARNO POTR/CARU
ABLA/BERE-JUCO
PIPO/CAGE POTR/CARO
ABLA/BERE-PIEN
PIPO/CELE POTR/FETH
ABLA/BERE-PIFL
PIPO/FEiD-ARPA POTR/TALL FORB
ABLA/BERE-PSME
PIPO/FEID-ARTR POTR/JUCO/CAGE
ABLA/BERE-RIMO
PIPO/FEID-FEID POTR/JUCO/LUAR
ABLA/BERE-BERE
PIPO/MUMO POTR/PTAQ
ABLA/CAGE
PIPO/PUTR POTR/SARA
ABLA/CARO
PIPO/QUGQ-SYOR POTR/STCO
ABLA/CARU
PIPO/QUGQ-QUGA POTR/SYOR/CARO
ABLA/JUCO
PIPO/SYOR POTR/SYOR/CARU
ABLA/OSCH
POTR/SYOR/THFE
FIRE GROUP FOUR ABLA/PERA-PSME
POTR/SYOR/FETH
PSME/ARPA ABLA/PERE-PERA
POTR/SYOR/TALL FORB
PSME/BERE-CAGE ABLA/PHMA
POTR/VECA
PSME/BERE-PlPO ABLA/RIMO-MEAR
POTR-ABLA/AMAL
PSME/CELE ABLA/RIMO-PICO
POTR-ABLA/CAGE
PSME/CEMO ABLA/RIMO-THFE
POTR-ABLA/CARO
PSME/QUGA ABLA/RIMO-RIMO
POTR-ABLA/JUCO
PSME/SYOR ABLAA/ACA
POTR-ABLA/SYOR/THFE
FIRE GROUP FIVE POTR-ABLA/SYOR/TALL FORB ABLAA/ACA-PIEN
ABLAA/AGL
PSME/ACGL POTR-ABLA/TALL FORB
ABLAA/AMY
PSME/BERE-JUCO POTR-ABCO/ARPA
ABLAA/ASC-ARLA
PSME/BERE-SYOR POTR-ABCO/POPR
ABLAA/ASC-CAGE
PSME/BERE-BERE POTR-ABCO/SYOR
ABLAA/ASC-VASC
PSME/CARU
POTR-PIPU
PSME/OSCH-PAMY POTR-PICO FIRE GROUP ELEVEN
PSME/PHMA POTR-PICO/CAGE ABLA/ACCO
PSME/PHMA-PAMY POTR-PSME/AMAL ABLA/ACRU
FIRE GROUP SIX POTR-PSME/JUCO ABLA/CACA
ABCO/ACGL POTR/ASMI ABLA/STAM
POTR/BRCA PIEN/EQAR
ABCO/ARPA
ABCO/BERE-JUCO POTR/JUCO/ASMI PIEN/CALE
PIPU/EQAR
ABCO/BERE-SYOR FIRE GROUP EIGHT
CONIFER/COSE
ABCO/BERE-BERE ABLAA/ACA
CONIFER/ACCO
ABCO/CELE ABLA/VASC-VASC
ABCO/JUCO PICO/ARUV FIRE GROUP TWELVE
ABCO/OSCH PICO/BERE ABLA/RIMO-TRSP
ABCO/PHMA PICO/CACA ABLAA/ASC-VASC
ABCO/QUGA PICO/CARO PIEN/RIMO
ABCO/SYOR PICO/JUCO PIENA/ACA
PIPU/AGSP PiCOA/ACA PIENA/ASC
2
classification ofthese vegetation types in Utah is not Abies concolor, white fir (ABCO)
complete. Abies lasiocarpa, subalpine fir (ABLA)
Habitat types and community types are desig- Acergrandidentatum, bigtooth or canyon maple
nated in the standard format of"series/type-phase," (ACGR)
in which "series" designates the potential climax Juniperus osteosperma, Utahjuniper (JUGS)
dominant tree, "type" designates a definitive under- Juniperus scopulorum, Rocky Mountainjuniper
growth species, and "phase" provides a further sub- (JUSC)
division where needed. Picea engelmannii, Engelmann spruce (PIEN)
— Piceapungens, blue spruce (PIPU)
Vegetation Following the list ofhabitat types
Pinus contorta, lodgepole pine (PICO)
that comprise each Fire Group, we describe the
Pinus edulis, pinyon pine or two-needle pinyon
characteristic overstory and undergrowth vegetation
(PIED)
for that Group. Climax and serai tree species are
Pinusflexilis, limber pine (PIFL)
identified.
— Pinus longaeva, Western bristlecone (PILO)
Forest Fuels The fuels likely to occur in each Pinus monophylla, singleleafpinyon (PIMO)
Fire Group are characterized in this section. The Pinusponderosa, ponderosa pine (PIPO)
emphasis is on downed and dead woody fuels. Live Populus tremuloides, aspen (POTR)
and standing dead fuels are also discussed where Pseudotsuga menziesii, Douglas-fir (PSME)
they contribute significantly to fire hazard. To date, Quercusgambelii, Gambel oak (QUGA)
there are no published summaries offuel loadings —
Fire Severity For the purpose ofthis report
by cover type or habitat type for coniferous forests
three levels offire severity are recognized: low or
and woodlands in Utah. Consequently, ifapplicable, cool, moderate, and high or severe. A low-severity or
fuel estimates fi*om surrounding States are pre-
sented. For each Fire Group, we discuss the kind cool fire is one that has minimal impact on the site.
and amount ofdead, woody material likely to be It burns in surface fuels consuming only the litter,
herbaceous fuels, and foliage and small twigs on
found on the forest floor.
— woody undergrowth. Very little heat travels down-
Role of Fire Information on the ecology ofthe ward through the duff. A moderate fire burns in
important trees, fuel characteristics, and the results surface fuels also but may involve a tree understory
offire history studies are integrated to describe the as well. It consumes litter, upper duff, understory
historical (presettlement period, generally prior to plants, and foliage on understory trees. Individual
the mid-1800's) role offire in shaping the vegetative and groups ofoverstory trees may torch out iffuel
composition ofa particular Fire Group. This section ladders exist. Aseverefire is one that burns through
is mainly a literature review covering succession and the overstory and consumes large woody surface
fire within the appropriate habitat types or plant fuels, or removes the entire dufflayer, or both, over
communities. much ofthe area. Heat from the fire impacts the
—
Forest Succession For each Fire Group, succes- upper soil layer and often consumes the incorpo-
sional pathway flow charts represent a synthesis of rated soil organic matter.
both knowledge and speculation about the effects of The amount ofsoil heating is critical to the sur-
fire at several points in the life history ofa stand. vival oftree roots and resprouting undergrowth spe-
They illustrate the many possible influences fires of cies. Observing soil surface characteristics after fire
varying severities have on stands ofdiffering ages, can help make predictions ofpostbum plant re-
densities, and species composition. The flow charts sponse more accurate. Ryan and Noste (1985) have
follow the method suggested by Kessell and Fischer presented some easily observable soil and fuel char-
acteristics to determine the relative depth ofchar in
(1981).
How trees respond to fire often depends on their different vegetation types (table 2).
—
size. Tre—e size classes used in our flow charts are: Fire Management Considerations This sec-
saplings 2 to 4 inc—hes in diameter at breast height tion discusses how the preceding information can be
(d.b.h—.); small poles trees 4 to 8 inches d.b.h.; large used to develop fire management plans that support
poles 8 to 12 inches d.b.h. (Society ofAmerican land and resource management objectives. Sugges-
Foresters, 1958). tions given are offered as an aid to decision making,
The tree species names are symbolized in order to but for specific situations the manager must rely on
simplify the diagrams and flow charts. The symbols personal experience to best determine how to use in-
are defined as follows: formation presented in this document.
3
—
Table 2 Visual character of ground char from observation of depth of burn^ (Ryan and Noste 1985)
Ground
char Site
class Timber/slash Shrub fields Grasslands
Unburned The fire did not burn on the See timber/slash See timber/slash
forest floor.
Some damage may occurto
vegetation due to radiated
or convected heatfrom
adjacent areas.
Ten to 20 percent of the
area within slash burns is
commonly unburned.^
There is a wide range in the
percent of unburned area within
fires in natural fuels.
Light Leaf litter is charred or Leaf litter is charred or Litter is charred or
ground consumed. consumed, and some leaf consumed, but some plant
char structure is still discernible. parts are still discernible.
Upper duff may be charred,
but the duff layer is not The surface is predomi- Charring may extend slightly
altered overthe entire depth. nantly black, although some into the soil surface, but
gray ash may be present the mineral soil is not
The surface generally appears immediately afterthe fire. othenwise altered.
black immediately after the fire.
Gray ash soon becomes Some plant parts may still
Woody debris is partially burned. inconspicuous. be standing.
Some small twigs and much of the Charring may extend slightly Bases of plants are not
branch wood remain. into soil surface where deeply burned and are still
leaf litter is sparse, but recognizable.
Logs are scorched or blackened the mineral soil is not
but not charred. otherwise altered. Surface is predominantly
black immediately afterthe
Crumbled, rotten wood is Some leaves and small twigs burn, butthis soon becomes
scorched to partially burned. remain on the plants. Burns inconspicuous.
are irregular and spotty.
Light ground char commonly makes Burns may be spotty to
up 0-100 percent of burned areas Less than 60 percent ofthe uniform, depending on the
with natural fuels and 45-75 brush canopy is commonly continuity ofthe grass.
percent of slash areas. consumed.
Moderate Litter is consumed.^ Surface leaf litter is Litter is consumed, and the
ground consumed. surface is covered with
char Duff is deeply charred or con- gray or white ash immediately
sumed butthe underlying mineral Some charred litter may afterthe burn.
soil is not visibly altered. remain but is sparse.
Ash soon disappears, leaving
Light-colored ash prevails Charring extends upto bare mineral soil.
immediately after the fire. 0.5 inch into mineral soil
but does not otherwise unarring exienas siigniiy
Woody debris is largely consumed. alterthe mineral soil. into mineral soil, but the
plant parts are no longer
Some branch wood is present, but Gray orwhite ash is con- discernible, no plant parts
no foliage or twigs remain. spicuous immediately after standing, and the bases of
the burn, but this quickly plants are burned to ground
Logs are deeply charred. disappears. level.
(con.)
4