2022 年 32 巻 S 号 p. 19-23
Desert greening and animal feed production are needed in the Republic of Djibouti, in east Africa. It is important to have information on the plants that are abundant in Djibouti. The Global Biodiversity Information Facility (GBIF) database records the occurrence of organisms worldwide by integrating specimens and discovery information. This study collected basic data on plant species in Djibouti, especially with regard to the frequency of occurrence of vascular plants, using the GBIF database, to understand the potential for greening and grazing.
In total, 6982 vascular plants from 561 species were in the GBIF database. The literature reports 783 vascular plant species in Djibouti. Thus, 71.6% of the species are in the GBIF database. The most frequently registered family was Fabaceae (19.2%), followed by Poaceae (10.9%), Asteraceae (8.0%), Solanaceae (4.8%), Malvaceae (4.4%), and Euphorbiaceae (4.4%). The most frequently registered species were Vachellia (previously Acacia) tortilis (3.8%), Solanum somalense (2.2%), and Rhigozum somalense (2.1%). Vachellia spp. accounted for five of the top 10 species. Fabaceae can grow on infertile soil because of nitrogen fixation. Poaceae and Asteraceae are recently evolved plant taxa that have adapted to arid land. The rank-frequency relationship of families and species (log-log scale) was significantly linear, where x denotes rank order of families or species, and y denotes frequency of occurrence, (log(y) = -1.24 log(x) + 7.70, (R2 = 0.93, P < 0.001), log(y) = -0.521 log(x) + 5.48, R2 = 0.98, P < 0.001), following Zipf’s law.
