Fern communities in lowland tropical forests of Brunei Darussalam, Borneo: diversity, indicator species, and environmental drivers across forest types

Ferns, as a large and biodiverse group, significantly contribute to the
vascular plant diversity of the lowland tropical forests of Brunei
Darussalam, Borneo. These forests encompass three main types: Mixed
Dipterocarp Forest (MDF), Peat Swamp Forest (PSF), and Heath
Forest (HF). This study aims to describe and compare fern communities in
these three forest types, focusing on species richness, diversity, and the
identification of indicator species. Additionally, it investigates the
environmental factors that shape these communities. We conducted fieldwork
in 48 plots across Brunei's lowland forests. We identified fern
species and abundance through a visual census and analyzed environmental
parameters, including soil pH, organic matter (OM)
content, nutrient availability, and soil texture. The results
showed 83 fern species, with MDF having the most (57 species). Peat
Swamp and HFs had similar fern species richness (33 and 34
species, respectively). Our environmental analysis indicated that
specific combinations of fern species and environmental
parameters significantly correlate and effectively discriminate between
the three forest types. Finally, we identified a selection of indicator
species for each forest type. Our findings highlight the heterogeneity of
Bornean lowland forests and the importance of preserving a diversity of
habitats to maintain fern biodiversity. The study underscores the
intricate interplay between environmental factors and fern diversity.This
dataset accompanies the manuscript “Fern communities in lowland tropical
forests of Brunei Darussalam, Borneo: diversity, indicator species, and
environmental drivers across forest types”. It consists of three Excel
files: 01_Species_abundance_plots.csv – Contains fern species composition
and abundance data from 48 forest plots. Rows represent species (with
family and scientific name), and columns represent plots. Cell values
indicate the number of individuals recorded per species per plot.
02_Species_Life_Forms.csv – Provides the life form classification
(epiphytic, climber, or terrestrial) for each fern species included in the
survey. 03_Environmental_Data.csv – Includes measured environmental
variables for each of the 48 plots, used to explore environmental drivers
of fern diversity and distribution. Together, these datasets support
analyses of fern community composition, species–environment relationships,
and potential indicator species across different forest types in Brunei.