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2002 Estimates of Old Growth Forests

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Table of Contents

2002 Estimates of Old Growth Forests
on the 18 National Forests
of the Pacific Southwest Region

Ralph Warbington and Debby Beardsley

US Department of Agriculture, Forest Service, Pacific Southwest Region

Abstract

Warbington, Ralph; Beardsley, Debby. 2002. 2002 Estimates of Old Growth Forests on the 18 National Forests of the Pacific Southwest Region. USDA Forest Service.

This monitoring report replaces previous estimates of old growth forests for National Forests in the Sierra Nevada and Klamath provinces. Comparisons of old growth forest areas were made of newer and previous estimates. First time estimates were developed for the National Forests in Southern California. Area tables are available by province, National Forest, and forest type.

Summary

New estimates of old growth conifer forests have been developed for the 18 National Forests in California, which are administered by the Pacific Southwest Region. For the first time, a consistent set of inventory sample plots and vegetation maps were available for obtaining these estimates, on all reserved and non-reserved lands within the National Forests. Vegetation plots, of a standard plot design and data elements, were collected from 1994 to 2000 using a 3.4-mile systematic grid sample framework. Additional plots were collected in rare forest types, using current vegetation maps to identify these areas for more sampling. Dates ranged from 1990 to 1997 for vegetation maps. The maps were developed from 30-meter TM satellite imagery, resource aerial photos and ground visitation, and served as the basis for stratification of all inventory plots. Old growth definitions for eleven conifer forest types were used as the basis for classifying plots as old growth. Productive conifer forest types without old growth definitions were assigned to one of the eleven definitions available. Plot expansion factors from existing vegetation maps formed the basis for estimating acres of old growth by National Forest, reserved and non-reserved lands. No attempt to estimate old growth hardwood forest conditions were made, due to lack of established ecological definitions for hardwood types.

Introduction

Old growth forests are of increasing importance as they contribute to the overall biodiversity of the National Forests, are key wildlife habitat of late serial dependent species, and store large amounts of carbon which contributes to the slowing of global warming. Historically, reductions in old forest condition were from two main causes, timber harvest and wildfire. Recently, harvest rates have been drastically reduced on the National Forests in California. Changes in land management plans, the Northwest Forest Plan and the Sierra Nevada Framework Plan, have provided land allocation and strategies for protecting the remaining old growth forests in the Region. A similar old growth forest strategy is a likely outcome for the Southern California Forests now under plan revision. Wildfire remains the final threat to the persistence of old growth forests areas on the National Forests.

Monitoring old growth forest conditions will need to continue as the basis for tracking losses and gains in this important natural resource. Permanent plots established through the Forest Inventory and Analysis program of the Forest Service, along with vegetation maps served as the basis of this monitoring report. The re-measurement of these same plots, with associated map updates, provides a continuous monitoring system of all forest conditions on the National Forests. Sampling site productivity, trees and large woody debris by species, size, frequency, and condition allowed for the classification of old growth using existing ecological definitions. This same data set could be used to estimate old growth for hardwood types, if ecological definitions become available.

Source Data for Old Growth Estimates

List of Source Data Information

Source Data Table

Existing vegetation maps and sample plots are the two major components used to estimate old growth forests on the National Forests in the Pacific Southwest Region. For this report, source information ranged from 1990 to 1997 for maps, and 1994 to 2000 for plots. Specific source dates by National Forest are shown in the Table below.

* The Vegetation Map date is based on the baseline source imagery date or the latest update date for changes due to fire, harvest, re-growth, and reforestation activities.

** The Sample Plots date is based on when the inventory was completed. Plot installation dates on a Forest range 1-3 years.

Existing Vegetation Maps

Existing vegetation maps form the basis for acreage estimates for land and water, forest and non-forest land, and defining sample populations for the stratification of ground plots into areas of similar vegetation types, tree sizes and canopy closure classes. The vegetation maps are also used to target additional sample plots for rare forest types and plantations.

Vegetation maps are developed from 30-meter TM imagery, field reconnaissance, map notes, photo editing, image classification for life form and forest size, forest canopy modeling for forest cover and GIS modeling for vegetation typing attributes. The CALVEG classification system is used to describe the floristic type of vegetation. Image segmentation is used to delineate vegetation stands or regions with a minimum mapping unit of 2.5 acres. Water bodies are incorporated from 1:24,000 scale USGS 7.5 minute quadrangle map base series cartographic feature files through GIS integration. Reforestation areas are incorporated from a 1:24,000 scale map of forest plantations based on agency records. Updates for changes are guided by change detection projects using TM imagery from two dates, as well as agency records of forest fires, fuel treatments, harvest, and reforestation activities. The resultant maps are available as a GIS coverage for each National Forest. An example of the existing vegetation map developed for an area on the Lassen National Forest from the process described is shown below.

Sample Area of Existing Vegetation Map on the Lassen National Forest

More information on the CALVEG classification and mapping program can be found at http://www.fs.fed.us/r5/rsl/projects/mapping/. To obtain existing vegetation GIS map coverages of the National Forests in the Pacific Southwest Region, go to http://www.fs.fed.us/r5/rsl/clearinghouse/forest-eveg.shtml.

Sample Plots

FIA (Forest Inventory and Analysis) sample plot locations are based on a systematic sample design consisting of cluster plots placed roughly 3.4 miles apart, one plot every 7,400 acres. The FIA grid design was established by the Pacific Northwest Research Station as the basis for sampling all forestlands within the State of California. On National Forest lands in the Pacific Southwest Region, all 3.4-mile sites were installed, on both forest and non-forest lands. Additional plots were installed to sample forest types that had too few samples from the 3.4-mile grid design. This occurs when a particular forest type on a National Forest has fewer than 40,000 acres. The existing vegetation map is used to identify areas of rare forest types, and is the basis for optimally allocating additional intensification ground samples on a 2.4-mile, 1.7-mile, or .85-mile grid within these mapped areas. A sample of 3.4-mile plus intensification plots for the Lassen National Forests is shown in the following graphic.

Number of Forestland Plots Classified for Estimating Old Growth Forest Condition

Lassen National Forest FIA Plot Layout

Each cluster plot consists of 5 independent subplots, sampling 2.5 acres and is installed in the field without rotation to avoid different vegetation conditions. If part of a plot crosses a vegetation type, forest size and or forest canopy cover class indicating a change in condition, portions of the cluster plot are assigned to different conditions by mapping, referred to as the mapped plot design. If a change occurred on a cluster plot, mapping was only done between subplots, and not within a subplot. At each subplot measurements of tree frequency, live or dead status, species, diameter, crown ratio, and damages were recorded. A sub-sample of trees was measured for age and height. Understory vegetation life form, species, cover and height as well as ground cover were estimated. Additional samples of down log frequency, species, large end size and length was measured along with estimates of fine forest fuels and fuel bed depth. Further information on the FIA plot design and measurement attributes used in these inventories can be found at http://www.fs.fed.us/r5/rsl/projects/inventory/sampling.shtml.

Linking Sample Plots to Vegetation Maps

Sample plots were linked to existing vegetation maps by assigning the vegetation map label from the map, where the plot is located. This is done through a GIS overlay of plot locations mapped from GPS and map vegetation polygons. Plots that fall near stand boundaries are reviewed for possible split conditions using aerial resource photos and heads up GIS views of vegetation maps and imagery. If the field installation did not recognize a split condition, then the plot is assigned to only one stand, and one map label. If the field installation mapped two or more conditions, then the best map labels are assigned to each split condition as indicated by the maps, photos and imagery. Approximately 10 percent of the cluster plots sample split conditions, where subplots are assigned to different forest populations in the vegetation map.

Developing a Population Strata Map and Inventory

Once map labels are assigned to each cluster plot/split condition, post stratification logic is assigned to the existing vegetation map. The goal is to obtain 6 or more cluster plots or 30 or more subplots per vegetation map stratum population to form a statistical sample for each vegetation condition. This in turn allows for estimating the area weight on the map that each sample cluster plot represents in the sample area expansion.

Using the post stratification process of assigning plots to map strata populations results in detailed population estimates of vegetation types, and reduces variance of overall estimates of basal area, number of trees, volume, growth and mortality. This is also useful in habitat modeling and estimating old growth forests since like vegetation types, forest size and condition are key attributes in estimating serial stages of vegetation conditions. The grid systematic sample, while a good design for tracking trends in changes over time, and for sampling common vegetation types and conditions adequately, can completely miss, and often inadequately samples rare forest types and structural conditions. Using vegetation maps to target additional plots compensates for these rare conditions, similar to what can be obtained with a stratified random sample design. Even with intensification, some rare forest types, size and canopy closure combinations have so few acres, they are still missed, and end up lumped into strata of the most similar type or structural condition.

The post stratification process starts with assigning an initial map stratum label to vegetation polygons that have the same life form, most similar floristic type and forest productivity. Some rare forest conditions, even with intensification plots, may have no further stratification for forest size and canopy cover characteristics. If more than 6 cluster plots occur within a general forest type, then forest stand size classes are used to further break out seedling, sapling, and pole sizes from small, medium and large sizes. More detailed breakdown of size classes is done if enough plots area available to do so. Within size classes, further breakdowns based on canopy closure classes of 20 to 50 percent are done, but only if enough plots still exist to create a meaningful statistical estimate. To assure consistent links of plots to a final strata map, all map labels are assigned to strata in a relational data base, and then the same logic is used assign strata labels to the plots, using the linked vegetation map label assigned to each cluster plot/split condition. A vegetation map label to strata crosswalk report is available for each National Forest at http://www.fs.fed.us/r5/rsl/projects/inventory/inv-download.shtml under the column Strata Xwalk. Here is an example report for the Lassen National Forest.

After assigning all map labels to strata labels, a GIS coverage is created by clipping the existing vegetation coverage with an administrative National Forest lands ownership coverage and then dissolving on like strata labels. The result is a simplified strata map where all polygons of the same stratum label represent the area of a vegetation population that is estimated by a set of sample plots with the same stratum label. An example map is shown below.

Sample Area of Strata on the Lassen National Forest

For more information on inventory strata maps, refer to the strata layer description found at http://www.fs.fed.us/r5/rsl/projects/frdb/layers/stra.html. For obtaining basic cluster plot data and vegetation inventory reports by plot and strata by Forest, go to http://www.fs.fed.us/r5/rsl/projects/inventory/forest-data.shtml.

Analysis Methods

List of Analysis Methods Information

Methods for estimating old growth on National Forests

Estimates of total area of forestland as well as total area of reserved, pending reserve, and available forestland were derived from the vegetation maps as described above. Areas were mapped as forestland if they had 10% cover of trees or if they were known to be stocked with trees at some time in the past and have the potential to have 10% cover of trees in the future. Estimates of old growth forestland and estimates of forestland by forest type were derived from the inventory plot expansions. Each plot was assigned an acre expansion depending on its stratum label (area of the stratum divided by the number of plots in the stratum), then typed and assessed for old growth. In our previous published estimates of old-growth in National Forests ("Old-growth Forests in the Sierra Nevada: By Type in 1945 and 1993 and Ownership in 1993", "Old-growth in Northwestern California National Forests") we did not have plots in reserves and had to use the strata maps and extrapolate from the plots outside of wildernesses to estimate old growth in those areas. Our plot sample for the current estimate covered all National Forest forestland, thus, old growth in reserve and available forestland could be estimated with the same methods.

Typing the Plots

If an inventory plot fell in a polygon mapped as forestland, it was considered forestland. Plots that had at least 10% absolute cover of conifers on it, were typed into one of the Society of American Foresters (SAF) conifer or conifer/hardwood mixed types using the key that follows the list of types below. A plot that had at least 10% cover of conifer but which was dominated by hardwoods might fall in an area mapped as hardwood but be classified as one of the conifer SAF types below because it had at least 10% cover of conifers on it. SAF type 234 (Pacific Douglas-fir/tanoak/madrone) and SAF type 243 (Sierra Nevada mixed conifer), in particular, can sometimes be dominated by hardwoods. A description of SAF forest types is in the Society of American Foresters' "Forest cover types of the US and Canada", edited by F.H. Eyre. In this analysis we used percentages of conifer basal area to type the plots into one of SAF types.

The SAF forest types do not necessarily consist of the same species across all of California. For instance, the Sierra Nevada mixed conifer type in the north may consist of Douglas-fir, white fir, ponderosa pine, incense cedar, black oak, and sugar pine but in the southern forests be dominated by bigcone Douglas-fir, Coulter pine or Jeffrey pine. (See Eyre F.H., Forest cover types of the US and Canada. Society of American Foresters, pages 118-119). Area by SAF type was derived from plot expansions.

Classifying the plots as old growth

Ecological old-growth definitions have been developed for the major SAF types in California. The purpose of the old-growth definitions was to identify by site class and forest type structural characteristics that indicated the onset of an old-growth stage. (see table 13, page 42 in "Old-growth Forests in the Sierra Nevada: By Type in 1945 and 1993 and Ownership in 1993" and table 12, page 43 in "Old Growth in Northwestern California National Forests" for definitions). However, ecological old growth definitions have not been developed for all the SAF types or for any of the pure hardwood SAF types. We did not assess old growth in the pure hardwood types. For the "other conifers" listed below we used a proxy definition, selecting a type with an old growth definition that would most closely match the form of the trees in a type with an old-growth definition. The table below shows which old-growth definition was used as a proxy for which type. Each of the plots with at least 10% cover in conifer were passed through the old growth algorithms by site class and forest type. Area of old growth by forest type was derived from plot expansions.

SAF Conifer and Conifer/Hardwood mixed types with old growth definitions

SAF Conifer types without old growth definitions

Key to SAF Conifer and Conifer/Hardwood Mixed Forest Types in California

1. If more than 33 percent conifer basal area is redwood, then type is
   SAF 232 redwood.
2. If more than 33 percent conifer basal area is Port-Orford-cedar, then type is
   SAF 231 Port-Orford-cedar.
3. If more than 90 percent conifer basal area is western juniper, then type is
   SAF 238 Western juniper.
4. If more than 25 percent conifer basal area is lodgepole pine and lodgepole pine has the plurality of the basal area stocking of species other than California red fir, then type is
   SAF 218 lodgepole pine.
5. If more than 80 percent conifer basal area is ponderosa pine and plot is east of the Sierra crest, (in the Modoc, Sierra or Mojave bioregions) then type is
   SAF 237 interior ponderosa pine.
6. If more than 80 percent conifer basal area is ponderosa pine and plot is west of the Sierra crest, then type is
   SAF 245 Pacific ponderosa pine.
7. If more than 50 percent conifer basal area is Jeffrey pine, then type is
   SAF 247 Jeffrey pine.
8. If more than 80 percent conifer basal area is comprised of ponderosa pine and Jeffrey pine:
   !     If plot is east of Sierra crest and there is more ponderosa pine than Jeffrey pine, then type is
   SAF 237 interior ponderosa pine.
   !     If plot is east of Sierra crest and there is more Jeffrey pine than ponderosa pine, then type is
   SAF 247 Jeffrey pine.
   !     If plot is west of Sierra crest and there is more ponderosa pine than Jeffrey pine, then type is
   SAF 245 Pacific ponderosa pine.
   !     If plot is west of Sierra crest and there is more Jeffrey pine than ponderosa pine, then type is
   SAF 247 Jeffrey pine.
9. If plot consists solely of ponderosa pine and juniper and more than 50 percent conifer basal area is in ponderosa pine, then type is
   SAF 237 interior ponderosa pine.
10. If more than 50 percent of conifer basal area is white fir and plot is in the Six Rivers National Forest or in the Ukonom, Happy Camp, or west Salmon River districts of the Klamath National Forest, then type is
    SAF 211 white fir-a.
11. If more than 60 percent of conifer basal area is white fir and plot is NOT in the Six Rivers National Forest or in the Ukonom, Happy Camp, or west Salmon River districts of the Klamath National Forest, then type is
    SAF 211 white fir-b.
12. If more than 10 percent conifer basal area is comprised of western white pine, whitebark pine, mountain hemlock, aspen, foxtail pine or Brewer spruce:
    !     If more than 60 percent of the conifer basal area is comprised of white fir, California red fir, and Jeffrey pine, then type is
    SAF 256-c mixed subalpine-white fir/Jeffrey pine.
    !     If more than 50 percent of the conifer basal area is comprised of western juniper, then type is
    SAF 256-d mixed subalpine-western juniper.
    !     If more than 50 percent of the conifer basal area is comprised of aspen, then type is
    SAF 256-e mixed subalpine-aspen.
    !     If more than 30% of the conifer basal area is comprised of mountain hemlock, and the mountain hemlock basal area exceeds western white pine, then type is
    SAF 256-b mixed subalpine-mountain hemlock.
    !     If more than 20% of the total basal area is comprised of western white pine, then type is
    SAF 256-a mixed subalpine-western white pine.
    !     If more than 20% of the total basal area is comprised of whitebark pine, then type is
    SAF 208 whitebark pine.
13. If more than 50% of conifer basal area is California red fir, then the type is
    SAF 207 California red fir.
14. If more than 80% of conifer basal area is comprised of California red fir and white fir:
    !     If there is more California red fir than white fir, then type is
    SAF 207 California red fir.
    !     If there is more white fir then California red fir and plot is in the Six Rivers National Forest or the Ukonom, Happy Camp, or west Salmon River districts of the Klamath National Forest, then type is
    SAF 211 white fir-a.
    !     If there is more white fir than California red fir and plot is NOT in the Six Rivers National Forest or the Ukonom, Happy Camp, or west Salmon River districts of the Klamath National Forest, then type is
    SAF 211 white fir-b.
15. If the plot is in the NORTH COAST or SOUTH CENTRAL COAST bioregions and more than 50 percent of conifer basal area is Douglas-fir (or if Douglas-fir is the sole conifer) and evergreen hardwoods (tanoak, Pacific madrone, canyon live oak) comprise at least 10 percent of conifer basal area and white fir is absent, then type is
    SAF 234 Douglas-fir/tanoak.
16. If the plot is in the NORTH COAST or SOUTH CENTRAL COAST bioregions and more than 50 percent of conifer basal area is Douglas-fir and evergreen hardwoods (tanoak, Pacific madrone, canyon live oak) comprise less than 10 percent of the conifer basal area or white fir is present, then type is
    SAF 229 Pacific Douglas-fir.
17. If more than 50 percent of the conifer basal area is comprised of a combination of Douglas-fir and ponderosa pine and Douglas-fir conifer basal area is > 20 percent and Ponderosa pine conifer basal areas is >20 percent and white fir is < 10%, then type is
    SAF 244 Pacific ponderosa pine-Douglas-fir.
18. If redwood or western hemlock or grand fir are present and redwood has the plurality of conifer basal area among these species, then type is
    SAF 232 redwood.
    Else type is
    SAF 224 western hemlock.
19. If more than 50 percent of the conifer basal area is comprised of a combination of Douglas-fir, ponderosa pine, white fir, incense-cedar, sugar pine, Jeffrey pine, California red fir, giant sequoia, big-cone Douglas-fir or Coulter pine, then type is
    SAF 243 mixed-conifer.
20. If none of the mixed-conifer species in step 19 are present and the plot has not been assigned to one of the other types in steps 1-19, a plurality of conifer basal area was used:
    A plot with a plurality of conifer basal area in gray pine was typed as
    SAF 250 blue oak-gray pine.
    A plot with a plurality of conifer basal area in knobcone pine was typed as
    SAF 248 closed cone pine.
    A plot with a plurality of conifer basal area in California juniper was typed as
    SAF 239 pinyon juniper.
    A plot with a plurality of conifer basal area in western juniper was typed as
    SAF 238 western juniper.
    A plot with a plurality of conifer basal area in bristlecone pine was typed as
    SAF 209 bristlecone pine.
    A plot with a plurality of conifer basal area in limber pine was typed as
    SAF 219 limber pine.
    A plot with a plurality of conifer basal area in cypress was typed as
    SAF 260 California cypress.

Results

The current estimates of old growth in National Forests shown in the tables below update and expand previous published estimates of old growth ("Old-growth Forests in the Sierra Nevada: By Type in 1945 and 1993 and Ownership in 1993", "Old Growth in Northwestern California National Forests"). The current estimates are based on the most recent inventory data (1994-2000) and inventory plots which samples all forestland, in and outside of reserves. In addition, these are the first estimates of old growth in the 4 southern National Forests.

We estimate that there are 2.2 million acres of old growth in National Forests in California or 15.7% of the total forestland. The forests with the most old growth are the Sierra, Inyo and the Shasta-Trinity. The majority of the old growth area is in higher-elevation types: red fir, mixed subalpine, lodgepole pine and Jeffrey pine. Over 70% of the lodgepole pine type is old growth. Whereas, the Ponderosa pine, white fir and redwood types have less than 10% of the type in old growth. Sixty percent of the old growth is in "available" forestland and 40% in reserves or pending reserves. The province of California with the greatest area of old growth is the Sierras where about 19% of the forestland is old growth.

The current estimate of old growth in all the Sierra Nevadan National Forests is about 500,000 acres greater than our published report using 1993 data. ("Old-growth Forests in the Sierra Nevada: By Type in 1945 and 1993 and Ownership in 1993"). The biggest increases in the Sierras occurred in the Sierra, Inyo, Plumas, Stanislaus and Eldorado National Forests. The increase in the estimate of old-growth in the Sierra Nevadas is most likely due to two factors: In the published report we extrapolated old-growth area in wildernesses from non-wilderness areas. We noted at the time that this may have underestimated old-growth in wilderness. In addition, the plot size of the plots used in the previous estimate of old growth for the Sierra, Tahoe, Sequoia, Tahoe Basin, Eldorado and Plumas was a 10 point cluster plot covering 10 acres. The current estimate was with a plot size of 5 points covering 2.5 acres. The smaller plot size in the Sierras would tend to "increase" the estimate of old growth because it could pick up smaller patches of old growth. This effect would not necessarily occur in the Klamath province because old growth is less patchy there.

Comparison of Current Estimate with Published Reports

* In the published report on old growth in the Sierras, "pending reserve" was included in the "available" class because it is not yet legally reserve.

The biggest increases in the Sierras occurred in the Sierra, Inyo, Plumas, Stanislaus and Eldorado.
The increase in the estimate of old-growth in the Sierra Nevadas is most likely due to two factors:

1. In the published report we extrapolated old-growth area in wildernesses from non-wilderness areas. We noted at the time that this may have underestimated old-growth in wilderness.
2. The plot size of the published data for the Sierra, Tahoe, Sequoia, Tahoe Basin, Eldorado and Plumas was a 10 point cluster plot covering 10 acres. The current estimate was with a plot size of 5 points covering 2.5 acres. The smaller plot size in the Sierras would tend to "increase" the estimate of old growth because it could pick up smaller patches of old growth. This effect would not necessarily occur in the Klamath region because old growth is less patchy there.

Old Growth Tables

List of Tables

Area (in acres) of forestland and old growth by National Forest and availability.

* Wildernesses or wild and scenic rivers by law.
** Pending legal designation as a wilderness or wild and scenic river.

Area of forestland and old growth in Region 5 National Forests by SAF forest type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Area of old growth in Region 5 National Forests by SAF forest type and availability class.

Area of old growth by SAF forest type and National Forest.

Angeles National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Cleveland National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Eldorado National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Inyo National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Klamath National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Lassen National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Los Padres National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Mendocinco National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Modoc National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Plumas National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

San Bernardino National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Sequoia National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Shasta-Trinity National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Sierra National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Six Rivers National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Stanislaus National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Tahoe National Forest by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Tahoe Basin Management Unit by SAF type.

* The proportion of forestland that is old growth does not include pure hardwoods or uninventoried forestland. It can be assumed that the non-stocked forestland (less than 10% cover of trees) is not old growth.

Area of old growth in Region 5 National Forests by elevation.

References

Beardsley, Debby; Bolsinger, Charles; Warbington, Ralph. 1999. Old-growth forests in the Sierra Nevada: by type in 1945 and 1993 and ownership in 1993. Res. Pap. PNW-RP-516. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 46 p.

Beardsley, Debby; Warbington, Ralph. 1996. Old Growth in Northwestern California National Forests. Res. Pap. PNW RP-491. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 47 p.

Bolsinger, Charles L.; Waddell, Karen L. 1993. Area of old-growth forests in California, Oregon, and Washington. Resource. Bull. PNW-RB-197. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 26 p.

Brown, Page. 1998. Climate, Biodiversity, and Forests: Issues and Opportunities Emerging from the Kyoto Protocol. ISBN Number 1-56973-285-x. World Resources Institute, 10 G Street, NE (Suite 800), Washington, DC. 40p.

Eyre, Et-t., ed. 1980. Forest Cover Types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p.

Fites, Jo Ann; Chapel, M.; Corbin, B. [and others]. 1991 a. Preliminary ecological old-growth definitions for mixed-conifer (SAF type 243) in California. Unpublished report, old-growth-define.pdf . U.S. Department of Agriculture, Forest Service, Pacific Southwest Region.

Fites, Jo Arm; Chapel, M.; Corbin, B. [and others]. 1991 b. Preliminary ecological old-growth definitions for white fir (SAF type 211) in California. Unpublished report, old-growth-define.pdf . U.S. Department of Agriculture, Forest Service, Pacific Southwest Region.

Fites-Kaufmann, Jo Ann; Franklin, Jerry F. 1996. Assessment of late-successional forests of the Sierra Nevada. In: Sierra Nevada ecosystem project, final report to Congress, vol. II, assessments and scientific basis for management options. Davis: University of California, Centers for Water and Wildland Resources: 627-662.

Hemstrom, Miles; Spies, Thomas; Palmer, Craig; Kiester, Ross; Teply, John; McDonald, Phil; and Warbington, Ralph. 1998. Late-successional and old-growth forest effectiveness monitoring plan for the Northwest Forest Plan. Gen. Tech. Rep. PNW-GTR-438. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 37 p.

Jimerson,T.; Bingham, B.; Solis, D.; Macmeeken, S. 199la. Ecological definition for old-growth Douglas-fir/tanoakIPacific madrone (SAF 234). Unpublished report, old-growth-define.pdf . U.S. Department of Agriculture, Forest Service, Pacific Southwest Region.

Jimerson,T.; Bingham, B.; Solis, D.; Macaneeken, S. 1991b. Ecological definition for old-growth Pacific Douglas-fir (SAF 229). Unpublished report, old-growth-define.pdf . U.S. Department of Agriculture, Forest Service, Pacific Southwest Region.

Old-Growth DefinitionTask Group. 1986. Interim definitions for old-growth Douglas-fir and mixed-conifer forests in the Pacific Northwest and California. Res. Note PNW-447. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 7 p.

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Northwest Forest Plan, Standards and Guidelines for Management of the Habitat for Late-Successional and Old-Growth Forest Related Species within the Range of the Northern Spotted Owl. Attachment A, ROD for Amendments to the Forest Service and BLM Planning Documents. 1994. U.S. Department of Agriculture and U.S. Department of Interior. 153 p.

Potter, D.; Smith, M.; Beck, T. [and others]. 1992a. Ecological characteristics of old-growth California mixed-subalpine forests. Unpublished report, old-growth-define.pdf . U.S. Department of Agriculture, Forest Service, Pacific Southwest Region.

Potter, D.; Smith, M.; Beck,T. [and others]. 1992b. Ecological characteristics of old-growth Jeffrey pine in California. Unpublished report, old-growth-define.pdf . U.S. Department of Agriculture, Forest Service, Pacific Southwest Region.

Potter, D.; Smith, M.; Beck,T. [and others]. 1992c. Ecological characteristics of old-growth lodgepole pine in California. Unpublished report, old-growth-define.pdf . U.S. Department of Agriculture, Forest Service, Pacific Southwest Region.

Potter, D.; Smith, M.; Beck,T. [and others]. 1992d. Ecological characteristics of old-growth red fir in California. Unpublished report, old-growth-define.pdf . U.S. Department of Agriculture, Forest Service, Pacific Southwest Region.

Sierra Nevada Forest Plan Amendment Record of Decision. 2001. U.S. Department of Agriculture, Pacific Southwest Region and Intermountain Region. 55 p.

Smith, S.; Laudenslayer, W.;Trask, J.; Armijo, M. 1991. Interim guidelines defining old-growth stands: Pacific ponderosa pine (SAF 245). Unpublished report, old-growth-define.pdf . U.S. Department of Agriculture, Forest Service, Pacific Southwest Region.

Smith, Sydney. 1991. Revised interim old-growth definitions for interior ponderosa pine (SAF 237). Unpublished report, old-growth-define.pdf . U.S. Department of Agriculture, Forest Service, Pacific Southwest Region.

Southern California National Forests, Notice of Intent, Proposed Action. 2001. U.S. Department of Agriculture, Forest Service, Pacific Southwest Region . 126 p.

U. S. Department of Agriculture, Forest Service, 1981. CALVEG: a classification of California vegetation, San Francisco, CA: Regional Ecology Group. U.S. Department of Agriculture, Forest Service.

U. S. Department of Agriculture, Forest Service, 2000. CALVEG Geobook, CDROM. On file with: Remote Sensing Laboratory, U.S. Department of Agriculture, Forest Service, Pacific Southwest Region, Sacramento, CA 95814.

U. S. Department of Agriculture, Forest Service, 2000. Forest Inventory and Analysis User's Guide. Unpublished document. On file with: Remote Sensing Laboratory, U.S. Department of Agriculture, Forest Service, Pacific Southwest Region, Sacramento, CA 95814.

Verner, Jared; McKelvey, Leven S.; Noon, Barry R. [and others], tech. coords. 1992. The California spotted owl: a technical assessment of its current status. Gen. Tech. Report, PSW-gtr-133. Albany, CA. U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 285 p.

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USDA Forest Service · Pacific Southwest Region