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INTRODUCTION TO EFFECTS OF FIRE MANAGEMENT ACTIONS ON CULTURAL RESOURCES. Nelson Siefkin, Archeologist Fire Management, Pacific West Region. DEFINING CULTURAL RESOURCES. Archeological Resources Structures Ethnographic Resources Cultural Landscapes Museum Objects.
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INTRODUCTION TO EFFECTS OF FIRE MANAGEMENT ACTIONS ON CULTURAL RESOURCES Nelson Siefkin, Archeologist Fire 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 RESOURCES Tangible 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
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
Context in space • Spatial attributes • Obsidian hydration rind • Technological attributes • Distinctive appearance • Chemical fingerprint • Use-wear/organic residues Different attributes of a feature or artifact are differentially impacted by direct fire effects Compromised >150 Deg. C Compromised >700 Deg. C Compromised variable temp Compromised variable temp Compromised at low temp What is it that we want to know?
Impediments to Accounting for Direct Effects Fire 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
Examples of Exclusionary Measures... Sprinklers, hoses, and wet lines
Examples of Exclusionary Measures... Fire retardant foams & gels
Examples of Exclusionary Measures... 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... POST-VEGETATION REMOVAL PRE-VEGETATION REMOVAL Manual Fuel Load Reduction
Archeological site (obsidian scatter) subjected to vegetation removal prior to prescribed burn at Lava Beds NM
A job too well done... Oops.
Examples of Non-Exclusionary Measures... Burning under circumstances that favor lower intensity fire…e.g., night ignition, backing fire
Examples of Non-Exclusionary Measures... 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 EFFECTS A 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... Construction of fire lines
Examples of Operational Effects... Fire camps, staging areas, helispots, etc.
Examples of Operational Effects... Fire retardant & water drops
Historic Residential Area at Mesa Verde NP Long Mesa Fire, 2002
Examples of Operational Effects... Mop-up and Rehabilitation
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
Examples of Indirect Effects... Increased Tree Mortality
1997 Sugarloaf WFU Burned Snag Shorty Lovelace at Crowley Cabin Pre-1940 2003 Williams WFU Examples of Indirect Effects... Increased Tree Mortality Shorty Lovelace Historic District Crowley Cabin Sequoia-Kings Canyon NP
Examples of Indirect Effects... Looting
Examples of Indirect Effects... 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 Discussion Group… http://groups.yahoo.com/group/fire_archaeology