Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN><SPAN>We used existing information to convey the general boundary and geographical limits of where Joshua trees occur on the landscape, as represented by polygons. The existing information comes from a number of sources, but primarily from Rowlands (1978, entire), Cole </SPAN></SPAN><SPAN STYLE="font-style:italic;"><SPAN>et al. </SPAN></SPAN><SPAN><SPAN>(2003, entire and 2011, entire) and Godsoe </SPAN></SPAN><SPAN STYLE="font-style:italic;"><SPAN>et al. </SPAN></SPAN><SPAN><SPAN>(2009, entire). The polygon maps were verified using Godsoe </SPAN></SPAN><SPAN STYLE="font-style:italic;"><SPAN>et al</SPAN></SPAN><SPAN><SPAN>. (2009, p. 592) who mapped 5,767 presence points across the Joshua tree range. Cole’s 2003 distribution mapping was updated in 2011 using presence points recorded in plots contained within the LANDFIRE Reference Database (2007, entire), the Central Mojave field data (Thomas </SPAN></SPAN><SPAN STYLE="font-style:italic;"><SPAN>et al. </SPAN></SPAN><SPAN><SPAN>2002, entire), and the Beatley Plots (Webb </SPAN></SPAN><SPAN STYLE="font-style:italic;"><SPAN>et al. </SPAN></SPAN><SPAN>2003, entire). The Service’s distribution map also incorporates a number of additional datasets (e.g., SEINet, Consortium of California Herbaria) that were combined to create the most likely distribution, or range boundary. The Service will continue to refine the polygon boundaries as more information is received on current Joshua tree distribution. </SPAN></P></DIV></DIV></DIV>
Copyright Text: US Fish and Wildlife Service; Center for Conservation Biology; UC Riverside; National Park Service, Joshua Tree National Park; iNaturalist; Bureau of Land Management; Jepson Herbarium; USGS Southwest Biological Service Center; Grand Canyon-Parashant National Monument; Godsoe et al, 2009; SEINet; California Deparment of Fish and Wildlife; Fort Irwin; Edwards Air Force Base.