CDF Report on Understocking of Pioneer Coastal Property

[Note: Bold Italics added for emphasis]

ANALYSIS OF THE 1997-99 POSTHARVEST INVENTORY FOR THE PIONEER COASTAL PROPERTY
May 18, 1999

Background

Coastal Forestlands, (CFL) obtained approval of their option A plan with the following conditions, as excerpted from CDF's May 4, 1998 letter.

The following assumptions are critical to the success of the proposed management:

1. Hardwood site occupancy reduced to not greater than 20% in 20 years.
2. Ingrowth will be sufficient to sustain selection management.
3. Residual stand damage will not inhibit individual tree growth or cause the harvesting of more trees than planned
4. Residual trees will be capable of releasing and accumulating the growth projected within the 10 years after harvest.
5. All mortality is captured

A monitoring program that addresses the above items is necessary to ensure timely adaption in management and/or adjustments to the option A projections. Failure to meet assumptions shall necessitate a re-analysis of the option A document with consequent adjustments to growth projections and allowable harvest.

The inventory that was planned was to sample the post-harvest areas for the 1997 and 1993 harvests. The existing permanent plots were to be used and augmented to "...be sufficient to meet a precision standard consisting of an allowable error of 20% of the mean basal area at a 95% level of confidence...". When the successor company, Pioneer Resources, attempted to relocate the permanent plot centers they could not find them. CDF cooperated with the company to design an inventory that addressed the issues of concern to the state. This analysis is based on the data collected using that inventory design.

Results

These results address the issues of site occupancy of conifers, tree damage inventory and growth. Ingrowth and mortality are most effectively evaluated over time.

Inventory

The inventory is based on 13,553 acres in parts of 66 timber harvest plans (THPs), A summary of basal area (ft2/acre), site occupancy based on basal area, and Scribner board foot gross volume is presented in table 1. These results are for all plots and do not distinguish between acres constrained by regulation, such as riparian buffers and unconstrained acres.

Table 1. Inventory of 1997-98 post harvest areas.

Species	Basal Area	Site Occupancy	Volume(BF)
Redwood	9.3		1,092.7
Douglas-fir	20.4		2,335.4
Sugar Pine	5.9		578.3
Other Conifers	0.1		6.8
Tanoak	31.5
Madrone	5.6
Other Hardwoods	9.5
Conifers	35.7	43.4%	4,013.2
Hardwoods	46.6	56.6%
Total	82.3	100.0%

The 95% confidence interval on the total basal area is 74.6-90.0. This is a 10% error and is well within the allowable error of 20%.

The property-wide site occupany of hardwoods, according to the option A plan, is 40%. This indicates that the site occupancy of the conifers is being reduced substantially. Removing cull and wildlife habitat designated trees from the inventory reduces the conifer stocking from 4,013.2 BF/Acre to 3,796.0 BF/Acre (3 5.7 ft2/ac to 34.7 ft2/ac basal area). Damage to the bole and tops of trees affect approximately 6% of the conifer trees.

Growth

Growth was estimated using increment data collected during the cruise. Table 2 is a summary of the current and projected conifer inventory. Gross board foot volume per acre is expected to increase from 4.0 MBF/Acre to 5.1 MBF/Acre in five years. This is an annual volume growth of 219 BF/Ac/Yr. This growth is substantially below the industry norms for the region and well below the productive capacity of the land, The property-wide average conifer volume from the option A plan is approximately 6.5 MBF/acre. The sampled areas will probably not recover to the pre-harvest level in ten years. Ten years is the planned re-entry period. This data shows that the conifer growing stock is being depleted so that current productivity is not being maintained. This data also indicates that the adequate site occupancy of conifers is not being met.

Table 2. Conifer inventory currently and projected in five years for the 1997-98 post harvest areas assuming no mortality.

Current			5-Years
Species	Basal Area	Volume(BF)	Basal Area	Volume(BF)

Redwood	9.3	1,092.7	12.6	1,393.4
Douglas-fir.	20.4	2,335.4	23.6	2,896.0
Sugar Pine	5.9	578.36	7.8	609.8
Other Conifers	0.1	9.2	0.2	13.76
Total	35.7	4,015.6	44.2	6,112.91

Methods

Check Cruise

CDF personnel conducted a check cruise of the inventory on May 13, 1999. THP 1-97-033MF-N (Benchie Basin) was visited and plots 74-79, 86-88 were measured. The THP appears to follow a watercourse with a narrow finger crossing the upper road. It appears that the plot line follows the adjacent watercourse to the west. This would place at least one plot out of the THP All of these plots were on steep slopes. There were some instances of hardwood species confusion, primarily between tanoak and true oaks.

THP 1-94-423 MEN (Roundhouse) was also visited. Plot numbers 310-315 were measured. These plots were on a ridgetop. The diameter measurements on the flat ground were much less variable than on the steep area. The total height and radial increment measurements that were checked were accurate.

(The report continues with details of the methodology and obtaining the measurements)

Report Prepared By:

Tim Robards
California Dept. of Forestry and Fire Protection
Forest Biometrician