The survey approximated that 38% of the trees on the site would be "transferable," implying that the rest would likely be cut down and discarded. You can download the full report on the website of San Bernardino County's Land Use Services Department in the list of EIRs. Scroll down to the Hacienda project for the "Joshua Tree Survey Report and Management Plan." In terms of Mojave Desert habitat, I'm not sure how prevalent Joshua Tree woodland is, especially since a good portion of woodland likely existed in the higher elevation areas surrounding the San Bernardino and Los Angeles mountains. Since this area is being squeezed by population growth, I am curious to know if woodland regions of the Mojave Desert are particularly imperiled compared to other habitat types, such as creosote scrub areas.
Above: Designed by Mother Nature to tolerate years of drought and extreme temperatures, but the Joshua Tree will be no match for a proposed massive residential development in Apple Valley
Below: A screenshot of the Hacienda at Fairview Valley Joshua Tree density report. Red and yellows are higher desnity and green is lower density Joshua Tree woodland.