introduction to effects of fire management actions on cultural resources nelson siefkin,...

INTRODUCTION TO EFFECTS OF FIRE MANAGEMENT ACTIONS ON CULTURAL RESOURCES

Nelson Siefkin, ArcheologistFire Management, Pacific West Region

DEFINING CULTURAL RESOURCES

• Archeological Resources

• Structures

• Ethnographic Resources

• Cultural Landscapes

• Museum Objects

ARCHEOLOGICAL RESOURCES

Physical remains of past human activity…prehistoric and historical

STRUCTURES

Material assemblies that extend the limits of human capability…domiciles, barns, bridges, dams, roads...prehistoric and historical

ETHNOGRAPHIC RESOURCESTangible and intangible manifestations of an extant cultural system…vegetation, spiritual/ceremonial sites, languages…generally associated with Native Americans/Hawaiians/Alaskans…often poorly understood

CULTURAL LANDSCAPES

Intertwined patterns of natural and cultural phenomena created by humans…prehistoric and historical

MUSEUM OBJECTS

Objects, specimens, and archival and manuscript collections…found in museums, exhibits, furnished structures, etc.

Cultural Resources of Interest

Critical to distinguish cultural resources of interest…those that are or have the potential to be important (e.g., NRHP listed and eligible) and have the potential to be impacted by fire management actions.

Historic properties--NRHP eligible or listed resources--are de facto resources of interest, but may also include those that do not meet NRHP criteria of significance.

Seemingly marginal cultural resources will become more significant as technology improves, urban encroachment intensifies, etc…Federal lands will become repositories for the preservation of in situ cultural resources

HistoricProperties

Resources ofInterest

Effects of Fire Management Actions on Cultural Resources

Conveniently divide into three types…

Direct Effects: Fire itself is the cause of impacts…due to direct flame exposure, excessive radiant heating, smoke damage, etc.

Operational Effects: Result from associated operations such as line construction, staging, etc. Especially common during the suppression of wildfires.

Indirect Effects: Fire and/or associated operations result in a change in local context such that resources are effected, e.g., erosion, high tree mortality.

DIRECT EFFECTS

Relate strongly to fire behavior…generally speaking, the heavier the fuel load, the more severe and intense the fire behavior, and the greater the potential for direct effects

Cultural Resources differentially impacted by direct fire effects…topic is not well understood

e.g., dimensional lumber ignites at 350 deg. C

glass melts above 400 deg. C

Some obsidian vesiculates above 700 deg. C

Different attributes of a feature or artifact are differentially impacted by direct fire effects

• Context in space• Spatial attributes

• Technological attributes

• Obsidian hydration rind

• Chemical fingerprint

• Distinctive appearance

• Use-wear/organic residues

Compromised >150 Deg. C

Compromised >700 Deg. CCompromised variable temp

Compromised variable temp

Compromised at low temp

What is it that we want to know?

Impediments to Accounting for Direct EffectsFire Behavior is extremely complex…is it reasonable to assume that we can control fire behavior such that damage threshold(s) will not be exceeded?

e.g., allow obsidian hydration rinds to be damaged, but keep fire cool enough so that obsidian artifact morphology is not effected.

Mitigating Direct Effects

Exclusionary Protection Measures

Exclusionary measures...preventing fire from burning on or in close proximity to a cultural resource through the use of some predetermined fire management action

Often employed when it is anticipated, given expected fire behavior, that the fire will burn at an intensity that exceeds the threshold above which a particular resource or resource attribute is impacted

Examples of Exclusionary Measures...

Fire Shelters


Sprinklers, hoses, andwet lines


Fire retardant foams & gels


Fire lines

Benefit of Exclusionary Measures…

Insure that cultural resources are not directly effected by fire

Potential drawbacks of exclusionary measures…

Leave islands of unburned fuel on cultural resources. These can be attractive to looters. Inevitably, unburned areas will eventually burn.

Non-Exclusionary Protection Measures

Non-exclusionary measures... intended to produce fire intensities below that expected to cause resource damage and/or that will not lead to future indirect effects. No attempt to exclude fire from the cultural resource.

Can be used in conjunction with exclusionary protection measures.

Examples of Non-Exclusionary Measures...

PRE-VEGETATIONREMOVAL

POST-VEGETATIONREMOVAL

Manual Fuel Load Reduction

Archeological site (obsidian scatter) subjected tovegetation removal prior to prescribed burn at Lava Beds NM

A job too well done...

Oops.


Burning under circumstances that favor lower intensity fire…e.g., night ignition, backing fire


Permanent or temporary artifact removal

Benefit of Non-Exclusionary Measures…

Allows fire to occur on cultural resources so that fuel loads are reduced

Potential drawbacks of non-exclusionary measures…

Difficulties associated with controlling fire intensity, uncertainty about direct fire effects on cultural resources

OPERATIONAL EFFECTSA large number of potentially damaging activities are carried out in conjunction with the suppression of wildfires

Most of these involve ground disturbance, although the range of potential effects are much greater

Satellite Photograph - Cerro Grande Fire Plume

Bandelier National Monument (Summer 2000)

Examples of Operational Effects...

Constructionof fire lines


Fire camps, staging areas, helispots, etc.


Fire retardant &water drops

Historic Residential Area at Mesa Verde NPLong Mesa Fire, 2002


Mop-up and Rehabilitation


Looting

INDIRECT EFFECTS

Indirect effects are fairly elusive…can occur while fire is still burning, shortly thereafter, or later in time

Can be difficult to recognize and evaluate

Examples of Indirect Effects...

Increased surface runoff and erosion

Post-burn eroding midden in Mojave National Preserve, 2005


Increased TreeMortality


Increased TreeMortality

Shorty Lovelace Historic DistrictCrowley CabinSequoia-Kings Canyon NP

Shorty Lovelace at Crowley CabinPre-1940

1997Sugarloaf WFU

2003Williams WFU

Burned Snag


Looting

Post-burn “Looter’s pile” at Mojave NP, 2005


Increased populations of burrowing rodents

Cultural Resource Hazards and the Resource Advisor

Resource Advisors can benefit operations by disclosing the location of potential hazards

For example, barbed-wire fences, subsurface mining features,toxic materials, explosives, etc.

Join the Fire Archeology DiscussionGroup…

http://groups.yahoo.com/group/fire_archaeology

introduction to effects of fire management actions on cultural resources nelson siefkin,...

Documents

marginal cultural resources

cultural phenomena

cultural resourcesconveniently

listed resources

situ cultural resourceseffects

direct effectsfire behavior

management actions

operational effects