Patterns of co-occurrence of epifoliar fungi in the Makiling Forest Reserve (MFR).

Abstract

Patterns and mechanisms of species co-occurrence in spatial and temporal considerations are noteworthy questions in community and conservation ecology. Much of the debate focuses on randomness or non-randomness in the structuring process of ecological assemblies, and the extent to which local/deterministic or regional/stochastic mechanisms may drive their composition. Here we studied assemblages of epifoliar fungi--diverse, mostly Ascomycetous microfungal unit communities typified by benign, asymptomatic and folicolous habit to determine its patterns of co-occurrence and to determine community diversity. We used a null model analysis of 30 identified morphospecies of epifoliar fungi found on 76 leaves from vascular plants along the Makiling Forest Reserve (MFR) understory. C-board, Combo and C-score indices were used to quantify co-occurrence and the Shannon-Wiener index to assess diversity at leaf- and whole MFR-levels. Species assemblages were shown to demonstrate segregative, non-random patterns of co-occurrence, as evidenced by C-Score (Obs=16.65517; Exp=15.86471; p=0.00000) and C-board scores (Obs=375.00000; Exp=363.08580; p=0.00030) that are greater than the expected null distribution, and a Combo score (Obs=36.00000; Exp=53.38610; p=0.00000) that is lower than the expected null distribution. While not evaluated in the study, plausible mechanisms that influenced the pattern observed, notably competitive exclusion and neutral processes, were discussed. Both leaf- and MFR-level Shannon-Wiener indices reveal a community of low species diversity, possibly an upshot of the segregative pattern observed.