The Vegetation Inventory Strata map is a derived layer from two main sources, the latest mid-level existing vegetation map and vegetation inventories. Strata represent subpopulations of sample plots, grouped by vegetation map labels to reduce the statistical variance of estimates. Related volume and biomass data is available in the R5_INV_LNK_AVERAGES table that joins to the feature class on INV_LNK. The volume and biomass values in this table are derived from vegetation inventories done on National Forests in Region 5. For further information go to: http://www.fs.fed.us/r5/rsl/projects/frdb/layers/stra.html
The vegetation inventory strata map provides a means of extrapolating per-acre forest inventory population estimates across an entire National Forest area through averaging FIA inventory plots within various forest conditions. .
Procedures Used - Strata population averages are calculated by grouping FIA plots by general regional forest and cover types. Forest stand structural components (overstory tree diameter and tree cover from above classes) or age classes are used for further dividing productive forestland populations. The most current mid-level existing vegetation map is used to post stratify the FIA plots by assigning map labels to each of the subplots for all FIA plots sampled on a National Forest, then sorting subplots using the assigned map labels into regional forest types and structural classes strata. The existing vegetation map is re-coded and generalized into inventory strata, using the same population grouping logic as the inventory plots. Strata features on the map are linked to the corresponding inventory strata averages. Where map strata areas exist, but lack sample FIA plots, inventory estimates with similar vegetation conditions are borrowed from adjacent National Forests to represent non-sampled areas. For more details on developing a population strata map and inventory, go to http://www.fs.fed.us/r5/rsl/projects/inventory/compilation.shtml#strata For Vegetation and Inventory data sources, go to: http://www.fs.fed.us/r5/rsl/projects/monitoring/inv-status.shtml
ground condition
Not recommended for use at scales greater than 1:24000
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Internal feature number.
ESRI
Feature geometry.
ESRI
Life form cover type
CALVEG Classification system
Vegetation type (Regional Dominance Type)
CALVEG Classification system
Timberland Productivity
Forest Inventory Planning Unit
A concatenation of regional forest type, tree size class and tree density
Concatenation of Forest Number, Planning Unit and Strata
Alternate link to the same or similar strata in the same or a neighboring forest
Forest Survey Site Productivity Class
Region 5 (R5) Site Class
Source EVEG polygon layer with year and version
Source Inventory plot layer with year and version
Administrative Forest Number
CALVEG zone
Length of feature in internal units.
ESRI
Area of feature in internal units squared.
ESRI
This product is reproduced from geospatial information prepared by the U.S. Department of Agriculture, Forest Service. By removing the contents of this package or taking receipt of these files via electronic file transfer methods, you understand that the data stored on this media is in draft condition. Represented features may not be in an accurate geographic location. The Forest Service makes no expressed or implied warranty, including warranty of merchantability and fitness, with respect to the character, function, or capabilities of the data or their appropriateness for any user's purposes. The Forest Service reserves the right to correct, update, modify, or replace this geospatial information without notification. For more information, contact the Remote Sensing Lab, 916-640-1256.
3237 Peacekeeper Way, Suite 209
Office is closed on federal holidays