Overview:
Description of the sampling density of completed soil survey efforts. Identification of under-sampled, critical areas (for solar-radiation modeling study), and creation of a sampling plan for spring 2007. A (nearly) design-based 'cluster random sampling' scheme (de Gruijter et al, 2006) will be used to address the main problems with collecting field samples at Pinnacles:

1. accessibility and navigation are limiting factors
2. travel time and navigation are equally problematic
3. significant gradients exist in known areas, and are of particular interest (landscape orientation and slope)

 
Planned Sampling Requirements:

• minimize travel time from park infrastructure
• maximize sampling in undersampled areas, across gradients (slope and solar insolation)
• minimize sample number for hypothesis testing
• minimize impact on park resources: condors and arch. sites

 
Observations and soil sampling at each site:

• field classification: mollic epipedon present and how thick
• field classification: litter layer present and how thick
• collection of material for total C and N analysis
• estimation of bulk density by ring method (3 reps for each lithology)
• A horizon thickness, texture, rock fragment content, and colors

 
Helpful References:

1. Dick, W.A.; Dane, J.H. & Topp, G.C. (ed.) Methods of Soil Analysis. Part 4: Pyhsical Methods Soil Science Society of America, Inc, 2002
2. de Gruijter, J.; Brus, D.; Bierkens, M. & Knotters, M. Sampling for Natural Resource Monitoring Springer, 2006

 

Proposed Sampling Sites
Several locations which meet the above criteria, and fill critical gaps in the soil survey pedon database have been selected (red and yellow markers). Depending on access, approximately 60 sites will be sampled this spring over the course of 2 days. Approximately 15 minutes will be spent at each site, with four workers, resulting in about 3.75 hours of time (per person) devoted just to sampling. The remaining time during each day will most likely be used accessing the sites. An approximate travel time from parking locations will be estimated to better judge time constraints.

Spring sampling mission points revision 1: Initial locations for spring 2007 sampling sites (red).

Spring sampling mission points revision 2: Secondary sampling sites for spring 2007 (yellow).

Spring sampling mission points revision 3: Third and final revision of spring 2007 sampling sites (red). Previously visited sites in blue, areas visible from condor facility in yellow. Contour lines represent 100m intervals from the condor facility.

Distance from Condor Facility: Simple 3D distance calculation from condor facility (yellow) and ridge line (black), contour interval is 100 meters. Proposed sampling sites are in red, condor facility in yellow.

Line of sight analysis from condor facility: Line of sight analysis based on an observer hight of 4 meters, from the condor facility. Colored regions represent areas visible from the view point (yellow symbol). Proposed sampling sites within this viewshed are circled with white.

Distance from Condor Facility by Sample Site: The distance from the condor facility to each proposed sampling point located on the hillslope above the campground. Points falling within the line-of-sight regions are colored red (site number 2).

Inter-pedon distance map: Map of inter-pedon (sample location) distances in meters.

Map of inter-pedon, slope-wieghted cost of reaching an unsampled location in the park: This map illustrates the relative difficulty of reaching unsampled locations within Pinnacles, based on the locations of existing observations and the cumulative change in slope one would have to over come to reach each unsampled location.

Pedon Density Estimation with a Voronoi Diagram: Visual estimation of sampling density with a Voronoi diagram. Polygon size is determined by the proximity of pedon sampling locations (larger polygons = less dense sampling).