Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN STYLE="font-weight:bold;"><SPAN>Title:</SPAN></SPAN><SPAN><SPAN> </SPAN></SPAN></P><P><SPAN><SPAN>Forest Conditions in the Northern Sierra Nevada, California – Digital Version</SPAN></SPAN></P><P /><P><SPAN STYLE="font-weight:bold;">Date started:</SPAN><SPAN><SPAN> </SPAN></SPAN></P><P><SPAN><SPAN>September 12, 2005</SPAN></SPAN></P><P /><P><SPAN STYLE="font-weight:bold;"><SPAN>Date completed:</SPAN></SPAN><SPAN><SPAN> </SPAN></SPAN></P><P><SPAN><SPAN>January 10, 2005</SPAN></SPAN></P><P /><P STYLE="font-weight:bold;"><SPAN><SPAN>Summary:</SPAN></SPAN></P><P><SPAN><SPAN>In 1902, the U.S. Geological Survey published </SPAN></SPAN><SPAN STYLE="font-style:italic;"><SPAN>Forest Conditions in the Northern Sierra Nevada, California</SPAN></SPAN><SPAN><SPAN>, by John B. Leiberg. This book contains generalized vegetation information on about 3.5 million acres between 39º and 40º N latitude and between 120º and 121.5º west longitude. This information is in the form of both a written description and maps of the area.</SPAN></SPAN></P><P /><P><SPAN><SPAN>In an effort to utilize the maps in this book in a GIS, we digitized the maps using ArcMap 8.3. First, all maps were scanned to a digital format (tif format). The digital maps were then georeferenced using ArcMap 8.3. Finally, we used on-screen digitizing techniques to delineate the polygons for each map unit of interest.</SPAN></SPAN></P><P /><P><SPAN><SPAN>There are four main themes in the Leiberg maps and in the final digital product.</SPAN></SPAN></P><OL STYLE="margin:0 0 0 0;padding:0 0 0 0;"><LI><P><SPAN STYLE="text-decoration:underline;"><SPAN>Cover</SPAN></SPAN><SPAN><SPAN> – The “cover” theme is divided into six distinct 30-minute quad maps (Bidwell, Colfax, Downieville, Sierraville, Smartsville and Truckee). In the “cover” theme, each polygon is labeled as either:</SPAN></SPAN></P><OL STYLE="margin:0 0 0 0;padding:0 0 0 0;"><LI><P><SPAN><SPAN>less than 2000 merchantable board feet/acre</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>2000-5000 merchantable board feet/acre</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>5000-10,000 merchantable board feet/acre</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>10,000-25,000 merchantable board feet/acre</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>greater than 25,000 merchantable board feet/acre</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>chaparral</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>cultivable</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>cultivated</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>pasture</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>rock</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>water</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>woodland</SPAN></SPAN></P><P><SPAN><SPAN>**** It is not clear whether the board/feet estimates in the maps are calculated using the “Michigan practice” or the “local practice”. The Michigan practice includes trees greater than 8” dbh and having at least 10 feet clear lumber in the trunk. The local practice includes pine trees over 12” dbh and fir trees over 16” dbh. Neither practice, we believe, includes incense cedar.</SPAN></SPAN></P><P /></LI></OL></LI><LI><P><SPAN STYLE="text-decoration:underline;"><SPAN>Culled Timber</SPAN></SPAN><SPAN><SPAN> – Polygons in this theme represent areas where cutting of trees has occurred, whether for timber, mining or fuel. No information exists as to the intensity the cutting. However, the intensity of cutting appears to vary from very light to complete clearing. The “culled timber” theme is divided into six distinct 30-minute quad maps (Bidwell, Colfax, Downieville, Sierraville, Smartsville and Truckee).</SPAN></SPAN></P><P /></LI><LI><P><SPAN STYLE="text-decoration:underline;"><SPAN>Species Distributions</SPAN></SPAN><SPAN><SPAN> – This theme shows the geographic distributions of:</SPAN></SPAN></P><OL STYLE="margin:0 0 0 0;padding:0 0 0 0;"><LI><P><SPAN><SPAN>Douglas fir</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>Grey pine</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>Mountain hemlock</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>Red fir</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>Sugar pine</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>Western juniper</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>Western white pine</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>Yellow pine (ponderosa and Jeffrey)</SPAN></SPAN></P><P /></LI></OL></LI><LI><P><SPAN STYLE="text-decoration:underline;"><SPAN>Fire</SPAN></SPAN><SPAN><SPAN> – These polygons represent fire perimeters and the intensity of those fires. The categories are as follow:</SPAN></SPAN></P><OL STYLE="margin:0 0 0 0;padding:0 0 0 0;"><LI><P><SPAN><SPAN>5-25% of timber burned</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>25-50% of timber burned</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>50-75% of timber burned</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>75-100% of timber burned</SPAN></SPAN></P></LI></OL></LI></OL><P><SPAN><SPAN> </SPAN></SPAN></P><P><SPAN STYLE="font-weight:bold;"><SPAN>Data format and delivery:</SPAN></SPAN></P><P><SPAN><SPAN>All data is delivered in a zip file named “leiberg.zip”. This zip file contains the following files and documents:</SPAN></SPAN></P><OL STYLE="margin:0 0 0 0;padding:0 0 0 0;"><LI><P><SPAN><SPAN>This brief final report (Leiberg_final_report.doc)</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>A geodatabase containing vector information for the four themes described above (Leiberg.mdb).</SPAN></SPAN></P></LI><LI><P><SPAN><SPAN>A folder labeled “images_rectified”, which contains the digitally-scanned, georeferenced images from which the geodatabase was digitized. </SPAN></SPAN></P></LI><LI><P><SPAN>FGDC metadata (leiberg_metadata.html). </SPAN></P></LI></OL><P><SPAN /></P></DIV></DIV></DIV>
Service Item Id: 376e1da5802844f1a3b1aa345cf1aa05
Copyright Text: Authors: Sean A. Parks and Sarah L. Thrasher
USDA Forest Service, Pacific Southwest Research Station, Sierra Nevada Research Center
2121 Second St., Suite A-101, Davis, California 95616
530-759-1717 (ph), 530-747-0241 (fx); sean_parks@fs.fed.us
Source: Leiberg, John B. 1902. Forest Conditions in the Northern Sierra Nevada, California. United States Geological Survey, Department of the Interior. Government Printing Office, Washington D.C.