Geospatial Distribution Pattern of Xanthostemon F. Muell. Species (Iron Wood) in the Philippines Based on Updated Literature and Internet Digital Checklist Platforms

Abstract

Unsustainable harvesting, land conversion, and mining activities have raised conservation concerns about the remaining stands of vulnerable to critically endangered Philippine Xanthostemon in its natural habitat and with restricted distribution. Mapping the current distribution is essential in developing conservation strategies and protecting these threatened species. This paper generated the distribution patterns of Xanthostemon in the Philippine islands by data mining from published and digital checklist platforms and translated them into distribution maps using Quantum Geographic Information System (QGIS). The data comprised 20 reported provincial occurrences of Xanthostemon species in the Philippines. Three endemic Xanthostemon species are widely distributed in selected provinces, and two have a restricted distribution pattern, making them more vulnerable to threats. Additional distribution of a possible introduced species, X. chrysanthus was reported in Agusan del Norte. The morphological description of the six Xanthostemon species reported was described based on the available data. The provinces of Leyte, Samar, Agusan del Norte, and Surigao del Sur obtained the highest number, having three species per province based on the number of reported occurrences. As per the island scale, Mindanao has the highest number of occurrences having ten provinces with four and one unidentified Xanthostemon species, naming it as the center of Xanthostemon in the country. Areas rich in heavy metals are a growing preference for ironwood and have been exploited for mining, which has been concluded for the threatened conservation status. The generated distribution map will significantly benefit from addressing intervention between local agencies and different sectors regarding the conservation and management of the natural population of Xanthostemon, especially in mining exploited areas, and could also serve as insight for further research into the collection of ironwoods for morphological, taxonomic, ecological, and molecular studies.