Contributions to the Central Luzon myxobiota: a rapid assessment of litter-inhabiting species in submontane forest on Mt. Mingan, Philippines

Abstract

The Sierra Madre Mountain Range, the longest mountain chain in the Philippines, serves as an important biogeographic corridor in Luzon Island but remains poorly studied for protistan diversity. Within this landscape, Mt. Mingan in Aurora Province has not yet been explored for myxomycetes. In this study, records were generated through direct field sampling of fruiting bodies and moist chamber preparation of aerial leaf litter (AL), ground leaf litter (GL), and twigs (TW) collected from two sites situated within the lowland areas to submontane forest zones of Mt. Mingan. A total of 109 records representing five orders, 14 genera, and 24 species were obtained. Seven species were classified as abundant with Arcyria cinerea having the highest number of records. Three species were common, four were occasional and 10 – rare, each represented by a single record. Although diversity values did not differ significantly between sites, Site 2 exhibited slightly higher species diversity than Site 1, and TW supported the highest taxonomic and species diversity among substrates. Community analysis yielded a Coefficient of Community value of 0.25 and a Percentage Similarity index value of 0.74 between sites, indicating that each site harbored a high number of unique taxa. Notably, this study provides the record of a rare species of the genus Physarina recovered directly from field collections. The species accumulation curve indicated that only 60% of the estimated diversity was recorded, suggesting that nearly half of the species present in the area remain undocumented, thereby warranting further systematic sampling. These findings highlight Mt. Mingan as a previously undocumented yet ecologically significant habitat for myxomycetes in Central Luzon, likely harboring many unreported species awaiting discovery. Additionally, previous surveys and checklists across Central Luzon have documented 97 species in 23 genera including 31 new records highlighting the region’s rich myxomycete diversity.