10.5061/DRYAD.0CFXPNW3V
Mežaka, Anna
0000-0002-1900-8614
Daugavpils University
Salazar Allen, Noris
Smithsonian Tropical Research Institute
Mendieta-Leiva, Glenda
0000-0002-0156-4153
Philipp University of Marburg
Bader, Maaike Y.
0000-0003-4300-7598
Philipp University of Marburg
Life on a leaf: the development of spatial structure in epiphyll communities
Dryad
dataset
2021
Community dynamics
epiphylls
rainforest
neighbour interactions
spatial association
spatial point pattern analysis
Stress-gradient hypothesis
European Union Framework Programme for Research and Innovation Horizon
2020, Marie Skłodowska-Curie action Global Fellowship*
project Nr. 708585 - EPIDYN
2021-12-01T00:00:00Z
2021-12-01T00:00:00Z
en
1540217 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
1. The spatial structure of biotic communities can be shaped by
niche-based or stochastic processes, and the importance of both can change
through time. Niche-based processes include neighbour interactions, which
can change in intensity and quality as communities develop in dependence
of environmental conditions. Epiphylls, miniature communities of
liverworts, lichens, algae and fungi on leaves, develop only in relatively
moist forests, but their leaf-surface habitat is still characterised by
moisture stress, especially in more exposed parts of the forest. As
neighbours may alleviate moisture stress, we expected that in forest gaps
(dryer, brighter) epiphyll communities would show more positive neighbour
interactions, resulting in more clustered spatial patterns, than in closed
forest, in accordance with the stress-gradient hypothesis. 2. To
understand how the processes shaping epiphyll communities change through
time and differ between gaps and closed forest, we examined the fine-scale
spatial structure within and between epiphyll functional groups (algae,
fungi, lichens, liverworts) during 12 months on 60 leaves across twelve
sites in a tropical rainforest in Panama. We analysed changes in spatial
positions and spatial associations within and between functional groups
using spatial point pattern analysis based on repeated photography. 3.
Epiphyll densities increased through time for most epiphyll functional
groups. However, although epiphyll groups changed their positions through
time, the general types of spatial patterns remained similar for most
groups: only lichen patterns shifted from mostly random to mostly
aggregated through time. We found only random and aggregated spatial
patterns within groups, while among groups we additionally found
segregated spatial associations, but no consistent temporal trend.
Patterns did not differ between gaps and closed forest, thus not
supporting the stress-gradient hypothesis. 4. Synthesis. Our results only
weakly support the assumption that community-shaping processes change from
neutral to niche-based as communities develop. We do provide empirical
evidence that epiphyll communities are dynamic and exhibit different
spatial association patterns within than among groups. This suggests
different interactions and processes within than between groups.
Experimental studies and monitoring of individual epiphyll patches are
recommended to shed further light on what processes shape life on leaves.
The dataset was collected based on digital photographies with tree or
shrub leaves with epiphylls, taken four times a year from the same
leaves in tropical rainforest on Barro Colorado island, Panama from the
November 2016 till November 2017. Each digital photography was processed
with Arcmap programme, where each epiphyll functional group patch (fungi,
algae, lichens, liverworts) and leaf shapes were mapped manually. For
spatial data analysis, centroids were calculated of each epiphyll
functional group patch.
The dataset was exported from Arcmap programme and consists of spatial
data files (shp) which can be processed with GIS programmes. Explanatory
file (txt) is attached to uploaded files.