The northern Mojave Desert, as are many deserts, is characterized in part by small "fertile islands" in which exist individual shrub clumps each containing two or more plants. These fertile sites promote characteristic organization of both plant and animal activity in the desert. Destruction of these fertile sites makes revegetation extremely difficult because most seedlings germinate in these sites. Some pioneer species do, however, germinate and survive in the bare areas between the fertile sites. Four such species in the northern Mojave Desert are Acamptopappus shockleyi Gray, Lepidium fremontii Wats., Sphaeralcea ambigua Gray, and Atriplex confertifolia (Torr. & Frem.) Wats. These four species may have a role in starting new fertile islands.
Wallace, A. and Romney, E. M.
"The role of pioneer species in revegation of disturbed desert areas,"
Great Basin Naturalist Memoirs: Vol. 4
, Article 5.
Available at: http://scholarsarchive.byu.edu/gbnm/vol4/iss1/5