First Year Ecological Effects of the Hoh Fire, Olympic Mountains, Washington

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Data_Quality_Information:

Lineage:

Methodology:

Methodology_Type: Field

Methodology_Identifier:

Methodology_Keyword_Thesaurus: None

Methodology_Keyword: aerial photo interpretation

Methodology_Keyword: vegetation survey

Methodology_Description:

Fire Extent and Intensity The Hoh Fire was photographed with color and color infrared film in September, 1978. From these photographs and ground observations in accessible portions of the fire, three fire intensity levels were mapped: (1) crown fire, where the overstory tree foliage was completely consumed by the fire, (2) crown scorch, where the fire did not consume the crowns but partially or totally scorched it, and (3) unburned islands, where little or no fire spread was apparent. Disturbance History Major forest disturbance processes were identified in the area of the Hoh Fire: snow avalanche, debris avalanche, wind, and fire. Snow and debris avalanches were mapped based on aerial photographs and ground checking. An extensive study of forest age was con- ducted using the ages of dominant trees. In most cases, Douglas-fir dominants were chosen, and ages were estimated by increment cores. The radius of the tree often exceeded the length of the borer, so that estimation of tree age was necessary. The establishment date of the present forest was estimated in three ways. The first was simply the age of the oldest specimen where little adjustment to age is necessary. The second was the age of the oldest tree, assuming a 0.5 cm ring width for uncored pith areas added to known core age. Using a ring width based on the inner rings of actual cores was rejected. It tended to overestimate age by applying to early years of growth a periodic increment calculated from a time period when the tree was older [e.g., Fritts (1976)]; estimates of uncored pith using this method ranged up to 40 percent of estimated age and resulted in ages considerably above those where much less estimation was needed for similar diameter trees. The third technique used to estimate establishment date was to make assumptions about the statistical distribution of sample trees and use characteristics of that distribution to estimate the date of disturbance. Using the subsequent regeneration pattern at the 1886-87 Cowlitz burn at Mount Rainier (Hemstrom 1979) as a more recent example, where delayed regeneration approached a normal distribution by the 1970s, it was assumed that neither the average nor the oldest aged sample tree might adequately characterize the disturbance date. Standardizing the graphed Cowlitz data allowed calculation of the area under the curve between the mean age of the regeneration and the known disturbance date. Using the 0.5 cm per ring assumption for the Hoh site, the mean age and standard deviation of twelve sampled dominant trees were calculated. When the same area under the curve was delineated, an estimated disturbance date was obtained. Forest Structure and Regeneration Vegetation and fuel characteristics were examined in burned and unburned reconnaissance- type plots in the montane zone during June, 1979. Randomly selected plots were located between 310-655 m elevation on moderately steep, south-to-southeast-facing slopes (132-170 degrees aspect; 10-105 percent slope). On each plot, tree basal area, density by height class, stand age, and herbaceous cover were measured. On most plots, selected fuel characteristics were also measured: litter and duff depths, fuel heights, and 10, 100 and greater than 100 hour timelag fuels. Basal area was measured using a 5 or 10 factor wedge prism. Live basal area and that killed by the Hoh Fire were measured so that pre-fire basal area could be determined. Density was measured on an ocularly established 100 m2 plot and segregated to live or dead in four height classes: 0.5-1 m, 1-3 m, 3-10 m, greater than 10 m. An herbaceous species list was made on the 100 m2 plot. Fuel characteristics were measured on up and cross slope line transects (Brown 1974). The 10 and 100-hour timelag down and dead fuels were inventoried using a 6 m line. A 20 m line was employed to measure greater than 100 hour sound, intermediate, and rotten fuels. Specific gravity values (USDA Forest Service 1955) were weighted by percent basal area on each plot, and were decreased by 0.05 and 0.1 for intermediate and rotten fuels. Quadratic mean diameters of 10 and 100 hour timelag fuels (Bevins 1978) were also weighted averages.

Process_Step:

Process_Description:

Statistical analysis was applied to burned and unburned plots for fuel characteristics. One way analysis of variance (ANOVA) was used where data met normality and homoscedasticity assumptions or could be transformed to do so (Sokal and Rohlf 1969). Otherwise the data were analyzed non-parametrically by the Mann- Whitney U-test. A total of six regeneration plot areas were- established in June, 1979: three in montane areas and three in subalpine areas, representing unburned, moderately burned, and intensely burned areas. Within each plot area, seven 1 m radius (3.14 m2) subplots were established at 5 m intervals along a line normal to contour. In late June and in early September, all tree seedlings less than 3 m height on each subplot were recorded by species, height class (0-1 dm, 1-2 dm, 2-5 dm, 5-10 dm, 1-3 m) and age class (1 yr - new seedlings, 2+ yrs). Two way ANOVA was applied to the first year regeneration data and all results mentioned as significant were tested at alpha = 0.05.

Process_Date: 1979

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Dr. James K. Agee

Contact_Organization: University of Washington

Contact_Position: Professor of Forest Ecology

Contact_Address:

Address_Type: Mailing and Physical Address

Address: University of Washington

Address: Box 352100

City: Seattle

State_or_Province: Wa

Postal_Code: 98195-2100

Country: USA

Contact_Voice_Telephone: 206/543-2688

Contact_Facsimile_Telephone: 206/543-3254

Contact_Electronic_Mail_Address: jagee@u.washington.edu

Distribution_Information:

Distributor:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Dr. James K. Agee

Contact_Organization: University of Washington

Contact_Position: Professor of Forest Ecology

Contact_Address:

Address_Type: Mailing and Physical Address

Address: University of Washington

Address: Box 352100

City: Seattle

State_or_Province: Wa

Postal_Code: 98195-2100

Country: USA

Contact_Voice_Telephone: 206/543-2688

Contact_Facsimile_Telephone: 206/543-3254

Contact_Electronic_Mail_Address: jagee@u.washington.edu

Resource_Description: journal article

Standard_Order_Process:

Non-digital_Form:

Article may be obtained through a library or though interlibrary loan

Metadata_Reference_Information:

Metadata_Date: 1990316

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Olympic Natural Resources Center

Contact_Position: GIS Specialist

Contact_Address:

Address_Type: Mailing Address

Address: PO Box 1628

City: Forks

State_or_Province: WA

Postal_Code: 98331

Country: USA

Contact_Voice_Telephone: 360.374.3220 x258

Contact_Facsimile_Telephone: 360.374.3336

Contact_Electronic_Mail_Address: onrc@u.washington.edu

Hours_of_Service: M-F 8-5

Contact_Instructions: Email preferred

Metadata_Standard_Name:

Content Standards for National Biological Information Infrastructure Metadata

Metadata_Standard_Version:

NBII Draft of December 1995, Based FGDC of June 8, 1994

Metadata_Access_Constraints: None

Metadata_Use_Constraints: None

Metadata_Security_Information:

Metadata_Security_Classification_System: None

Metadata_Security_Classification: Unclassified

Metadata_Security_Handling_Description: None