USDA Forest Service
 

Adaptive Management Services

 
 

United States Department of Agriculture Forest Service, Enterprise

United States Department of Agriculture USDA Forest Service Enterprise - Reinvention Lab

Projects

Joint Fire Science / NASA Project

Project Summary

Methods
General Study Area

Two study sites were established in the Sierra Nevada mountain range of California, representing the northern and southern areas of the bioregion. The northern location is on the Plumas National Forest, encompassed by the Herger-Feinstein/Quincy Library Group EIS area. The southern location is on the Sierra National Forest, and includes the King’s River Administrative Study Area and the Teakettle Experimental Forest. A third site that may or may not be included, is in the central Sierra Nevada on the Lake Tahoe Basin.

The northern project site was located approximately 40 km west of Quincy, CA (T 24N, R 9E, Section 14) at elevations of 1200 to 1850 m. The study area covered ˜ 20,000 hectares of coniferous forest and spanned in latitude from 39º 47’ 30” to 39º 57’ 30” and in longitude from 120º 57’ 30” to 121º 12’ 30”. The northern Sierra Nevada has a warm, dry summer and a cool, wet winter climate. Vegetation types include mixed conifer forests of white fir (Abies concolor), ponderosa pine (Pinus ponderosa), incense cedar (Calocedrus decurrens), sugar pine (Pinus lambertiana), and Douglas fir (Pseudotsuga menziesii ), with ponderosa pine dominate in relatively dry locations and white fir dominate in moister locations. Upper elevation plots consisted of red fir (Abies magnifica) and Jeffrey pine (Pinus jeffreyi) dominated vegetation types (Sawyer and Keeler-Wolf, 1995).

The southern project study area was located approximately 80 km east of Fresno, CA (T 13S, R 20E) at elevations of 1500 to 2600 m. The project area covered ˜ 40,000 hectares of the Sierra National Forest and spanned in latitude from 36º 55’ to 37º 20’ and in longitude from 119º 00’ to 121º 12’. The southern Sierra Nevada has a warm, dry summer and a cool, wet winter climate. Vegetation types include lower elevation mixed conifer forests of white fir (Abies concolor), incense cedar (Calocedrus decurrens), sugar pine (Pinus lambertiana), and Jeffrey pine (Pinus jeffreyi). Upper elevation plots consisted of red fir (Abies magnifica), lodgepole pine (Pinus contorta), and western white pine (Pinus monticola) vegetation types (Sawyer and Keeler-Wolf, 1995).

Site Selection

A minimum of 30 plots per major vegetation type, varying in structure, physiognomy and lifeform and thus predicted to differ in crown characteristics, were estimated as necessary to provide sufficient data and ground measurements of canopy characteristics (crown height, height to live crown, crown biomass, crown bulk density). With at least 5 different vegetation types within the major study locations, a minimum of 300 plots needed to be established. This estimate did not include additional plots for later accuracy assessment.

A point matrix with a 600-meter spacing was generated for the study area. The point matrix was buffered by 56.42 meters to produce a one-hectare sample polygon coverage. Six hundred meter spacing was selected because the area covered by the 600-meter spaced one-hectare polygons is about 3% of the total study area.

Spacing Ha-Plots Ha-Total Percent Number of Plots
600m
437.4
4929.4
2.93%
405

Prior to making the random selections, the road network was buffered by 10 meters and intersected with the one-hectare plot pool to identify those plots touching roads. Seventy one hectare plots which intersected the road network were eliminated from the plot selection pool resulting in a pool size of 335 plots. Then 224 plots were randomly selected for field data collection from the plot pool.

Once the grid system was completed, some of the plots were eliminated. A stratification process tallied plots by major physiognomic groups (ex. shrub, plantation, large trees, previously logged areas, rock outcrops) to ensure adequate representation. Overabundant plots of one physiognomy were eliminated to allow for adequate sample sizes of all vegetation types. In addition, plots located on top of existing roads were either eliminated or systematically shifted to the west. Depending on the edges of contrasting patches, plots were shifted to the west 56. 4 m. If the western shift was unsuitable, plots were moved east, north or south in consecutive order


PROJECT INFO
Project Summary
  Background
  Methods
  Design
  Deliverables
Progress to Date
Planned Work
JFS/NASA Investigators
Study Area Map [ PDF ]
Project [ PDF ]

 

USDA Forest Service - Adaptive Management Services Enterprise Unit
Last Modified: Monday, 16 December 2013 at 14:19:00 CST