The 2002 data were developed by Aaron Di Orio, California Department of Fish and Game, Region 1. The 1946 and 1994 data were developed by: Jason Schwenkler, Geographical Information Center, Chico, CA - schwenkler@gic.csuchico.edu 20040801 vector digital data https://wildlife.ca.gov/Data/BIOS https://filelib.wildlife.ca.gov/Public/BDB/GIS/BIOS/Public_Datasets/100_199/ds112.zip This dataset displays aspen stands in the Warner Mountains south of State Highway 299. The 1946 and 1994 data are presented as polygons depicting aspen stands derived from aerial photos taken in 1946 and 1994, respectively, while the 2002 data includes the aspen stand delineations and their corresponding vegetation data (i.e., size distribution of aspen, the canopy and shrub cover, the number of species of grasses and forbs, and the ratio of conifers to aspens). The polygons ranged in size from less than 0.2 acres to more than 1,130 acres. There are 2103 records, one for each aspen stand mapped and sampled. All data were collected and summarized by Aaron Di Orio, California Department of Fish and Wildlife. This is one of three data sets for a study investigating change in the size of aspen stands since 1946. Other available data sets are 1946 and 1994 aerial photo mosaics. The purpose of the project was twofold: 1) To detect changes in the amount and distribution of aspen within the study area in the South Warner Mountains over a 48 year duration using aerial photograph interpretation. 2) To collect field data on the current condition of aspen stands, and their use by wildlife. METHODS: An initial visit to the project area was taken where field studies in aspen stands were being conducted. Discussion was held on mapping aspen stand perimeters, associated vegetation, and other field techniques with field crew members. The 1946 photographs, with some preliminary aspen stands mapped, were also looked at in the field. GPS points and perimeters were obtained from the field study efforts to use for reference purposes in the historic aspen mapping. ArcView 3.X was used to create the aspen layer using heads-up digitizing from stereo pair ortho photographs. Visual identification, stereoscopes, and the GPS points and perimeters were all used to find and identify aspen polygons. In general, individual aspen stands were visually identified by differences in color and texture on the black and white aerial photographs. In areas where shadows appear, aspen is mixed with conifers, or immature trees that may be confused with shrubs, the stereoscope and reference GPS points and perimeters were used to help determine if stands were aspen or other species. A code system was developed to reference certainty of identification. A rating system of 1 to 3 was used with 1 being certain, 2 fairly sure and 3 being questionable and with a possible conifer content (see 'comment' field). Stands where a 2 or 3 certainty code was used may be candidates for future field checks. In transition areas, a polygon line is drawn to confine the aspen and exclude the mixed conifer-aspen. For the 2002 data, all vegetation and pellet data for each stand were obtained by measuring these characteristics in 10m by 10m plots, with the number of plots (1 to 6) dependent on the size of the stand being surveyed. The values of the variables in this data set are intended to represent the entire stand by averaging the values obtained from all the sample plots within each stand. A Trimble GeoExplorer III GPS receiver was used to determine the extent of the aspen stands. Coordinates were originally measured in UTM NAD27. Complete None planned -120.334784 -120.098094 41.521078 41.071003 None Aspen Populus tremuloides vegetation structure stand size distribution trend ISO 19115 Topic Categories location None California Modoc Warner Mountains Department of Fish and Game use only. License: This work is licensed under Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). Using the citation standards recommended for BIOS datasets (https://www.wildlife.ca.gov/Data/BIOS/Citing-BIOS) satisfies the attribution requirements of this license.Disclaimer: The State makes no claims, promises, or guarantees about the accuracy, completeness, reliability, or adequacy of these data and expressly disclaims liability for errors and omissions in these data. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, fitness for a particular purpose, and freedom from computer virus, is given with respect to these data.Check with Contact person for use constraints. California Department of Fish and Wildlife, Region 1 Aaron Di Orio physical

Shasta Valley Wildlife Area

1724 Ball Mountain Road

Montague CA 96064 US 530-340-3913 adiorio@dfg.ca.gov The 2002 data were collected and summarized by Aaron Di Orio, California Department of Fish and Wildlife, Region 1. The 1946 and 1994 data were collected and compiled by Jason Schwenkler, Geographical Information Center, Chico, CA - schwenkler@gic.csuchico.edu Microsoft Windows Vista Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 9.3.1.4095 Vector GT-polygon composed of chains 2102 NAD 1983 California Teale Albers 34.0 40.5 -120.0 0.0 0.0 -4000000.0 coordinate pair 0.0001 0.0001 meter D North American 1983 GRS 1980 6378137.0 298.257222101 ds112 In summer 2002, aspen (Populus tremuloides) stands were identified in the South Warner Mountains. The perimeter of each stand was delimited via GPS. Within each of these stands, 1-6 vegetation sample plots (10m x 10m) were measured. The number of plots measured per stand was determined by stand size. The values of the variables in this dataset are intended to represent the entire stand by averaging the values obtained from all the sample plots within each stand. The abbreviation "POTR" represents Populus tremuloides, or aspen. Shape_Length Length of feature in internal units. Esri Positive real numbers that are automatically generated. Shape Feature geometry. ESRI Coordinates defining the features. SHAPE_area Area of feature in internal units squared. ESRI Positive real numbers that are automatically generated. ACRES Approximate area of stand in acres. YEAR Year AREA_ Area of polygon in square meters PERIMETER_ Length of perimeter in meters COMMENT Rating system for confidence in aerial photo interpretation. 1 Certain 2 Fairly certain 3 Questionable and with a possible conifer content. STAND_CODE Unique identifier for aspen stands. DOMSIZE Dominant size class of the stand. Dominance was calculated as total basal area of trees using the median Dbh value for each Dbh class. CON_ASP_RA Conifer to aspen ratio for the stand. PCTCC Average percent canopy closure among plots for the stand. PCTSHRBCOV Average percent shrub cover among sample plots for the stand. FORBSPP Average number of forb species among sample plots for the stand. GRASSSPP Average number of grass species among sample plots for the stand. SUCKERS_PE Average number of aspen suckers <1" Dbh per acre within the stand. POTR2ACRE Average number of aspens 1-2" Dbh per acre within the stand. POTR2_4ACR Average number of aspens 2-4" Dbh per acre within the stand. POTR4_8ACR Average number of aspens 4-8" Dbh per acre within the stand. POTR8_12AC Average number of aspens 8-12" Dbh per acre within the stand. POTR12_16A Average number of aspens 12-16" Dbh per acre within the stand. POTR16ACRE Average number of aspens >16" Dbh per acre within the stand. X1_POTR Average number of aspens <1" Dbh among sample plots for the stand. X2_POTR Average number of aspens 1-2" Dbh among sample plots for the stand. X2_4POTR Average number of aspens 2-4" Dbh among sample plots for the stand. X4_8POTR Average number of aspens 4-8" Dbh among sample plots for the stand. X8_12POTR Average number of aspens 9-12" Dbh among sample plots for the stand. X12_16POTR Average number of aspens 12-16" Dbh among sample plots for the stand. X16_POTR Average number of aspens >16" Dbh among sample plots for the stand. PCTCONCEAL Average percent concealment among plots for the stand. Concealment was measured at a distance of 61m using a 1m x 1m sight target board, set vertically on the ground and facing the observer, in 4 directions at each plot and averaged. SUMDEERP Average number of deer pellets counted among sample plots for the entire stand. SUMELKP Average number of elk pellets counted among sample plots for the entire stand. SUMCOWP Average number of cow pies counted among sample plots for the entire stand. SUMSHEPP Average number of sheep pellets counted among sample plots for the entire stand. GPS_DATE Date of GPS collection of stand location and perimeter. GPS_TIME Time of GPS collection of stand location and perimeter. DATAFILE GPS file name. HECTARES Approximate area of the stand in hectares. UNFILT_POS Feature geometry. Esri Coordinates defining the features. SHAPE Feature geometry. ESRI Coordinates defining the features. In summer 2002, aspen (Populus tremuloides) stands were identified in the South Warner Mountains of Modoc County, CA. The perimeter of each stand was delimited via GPS. Within each of these stands, 1-6 vegetation sample plots (10mx10m) were measured. The number of plots measured per stand was determined by stand size. The values of the variables in this dataset are intended to represent the entire stand by averaging the values obtained from all the sample plots within each stand. The abbreviation "POTR" represents Populus tremuloides, or aspen. 20210609 Region 1, California Department of Fish and Wildlife Aaron Di Orio mailing and physical

Shasta Valley Wildlife Area

1724 Ball Mountain Road

Montague CA 96064 US (530) 340-3913 adiorio@dfg.ca.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 local time