In: Sydowia 77, (2024): 129-139; ISSN 0082-0598, DOI 10.12905/0380.sydowia77-2025-0129, Published online on October 28, 2024

Protosteloid amoebal assemblages as microbial models for elevational diversity gradient in tropical montane landscape

Akira T. Komoda, Lanz Aidan Daryll A. Tan, Allan Miguel G. Tomimbang, Kristian Andrei R. Tan, John Carlo Redeña-Santos, Nikki Heherson A. Dagamac* & Christian Elmarc Ocenar-Bautista

1 Department of Biological Sciences, College of Science, University of Santo Tomas, España 1008 Manila Philippines
2 Initiatives for Conservation, Landscape Ecology, Bioprospecting, and Biomodeling (ICOLABB), Research Center for the Natural and Applied Sciences, University of Santo Tomas, España 1008 Manila Philippines
3 The Graduate School, University of Santo Tomas, España 1008 Manila Philippines
4 D’ABOVILLE Foundation and Demo Farm Inc., 1200 Makati City, Philippines
* e-mail: nhadagamac@gmail.com

Komoda A.T., Tan L.A.D.A, Tomimbang A.M.G., Tan K.A.R., Redeña-Santos J.C., Dagamac N.H.A. & Ocenar-Bautista C.E. (2023) Protosteloid amoebal assemblages as microbial models for elevational diversity gradient in tropical montane landscape –
Sydowia 77: 129–139.

Protosteloid amoebae are small, fungus-like protists belonging to Class Amoebozoa whose diversity and distribution in the Southeast Asian tropics remained little known. A systematic collection of aerial and ground litter collected at different elevation belts (0–300, 301–600, 601–900, 901–1200, 1201–1500 m a.s.l.) on the north- and south-facing slopes of Mt. Calavite Wildlife Sanctuary (MCWS), Philippines was cultivated on weak malt yeast agar (wMYA). A positive wMYA plate where morphologically determinable protosteloid amoebae were distinguished served as a taxonomic unit for the ecological analysis employed in PAST (Paleontological Statistics) and R studio. The following trend was observed amongst the protosteloid amoebal communities: (i) highest species diversity was found on middle elevation, aerial substrates, and south-facing slope; (ii) the cosmopolitan species Protostelium mycophagum appeared to be the most abundant; and (iii) the beta diversity clusters lower elevation and higher elevation sites separately indicating variations in species composition. Interestingly, the ecological pattern of elevational diversity gradient (EDG) applied to macroorganisms seems to be a potential pattern even in cultivable fruiting bodies of protosteloid amoebae. This work is the first in-depth species diversity study of protosteloid amoebae in the Philippines and the whole of Southeast Asia.

Keywords: abundance, eumycetozoan, microbial ecology, morphological species concept, slime molds.