EpIG: Epiphyte Inventory Group
Vascular epiphytes are a conspicuous component of most tropical forests, comprising up to 50% of the local diversity in some tropical rainforests. While small-scale distributional patterns are increasingly well understood, there is limited knowledge of their regional diversity patterns, and little to no theoretical understanding of the processes and mechanisms driving diversity in this ecologically important group. Diversity patterns are the result of multiple processes at multiple scales. Without studying patterns and drivers at a large scale we will not be able to understand epiphyte diversity fully.
Conceptually, there are two other types of structurally dependent plants sharing the habitat and some ecological characteristics with epiphytes (more about epiphytes in Spanish here):
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Our interest group focuses on vascular epiphyte diversity. We formed the group in the course of an international epiphyte workshop in August 2018 and together we created a platform to consolidate our databases collected throughout the Neotropics.
OUR GOAL:
To bring together epiphyte inventory data from across the world
EPiG-DB: A Database of Vascular Epiphyte assemblages in the Neotropics
The first output of our group is “EpIG‐DB: A database of vascular epiphyte assemblages in the Neotropics", published in January 2020 in the Journal of Vegetation Science.
Figure 1: EpIG‐DB A database of vascular epiphyte assemblages in the Neotropics.
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Figure 2: Graphical representation of the structure of epiphyte inventory data.
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EpiG-DB 1.0
The current version of EpiG-DB consists of 463,196 individuals from 3005 species (including 960 morphospecies) belonging to 60 families and 411 genera, collected from 18148 relevés (17762 trees and 386 understory plots) with 76% of trees sampled within 687 forest plots (Fig. 2).
Figure 3: Spatial distribution of the 40 datasets integrated in EpIG‐DB 1.0 across the Neotropic WWF biomes.
All in all, 40 datasets have been gathered from 9 countries, 6 biomes and 45 ecoregions in the Neotropics (Fig. 3). More than half of the relevés (66%) are distributed in natural ecosystems, only 19% are found in anthropogenic areas and 15% in semi-natural ecosystems. We need more data for disturbed or regenerating sites!
Figure 4: Climate envelope of EpIG‐DB 1.0 data across Whittaker biomes.
The spatial distribution of datasets, indicates data deficient areas; for instance, the Amazonian and the Caribbean, where more data needs to be collected (Fig. 5).
Because EpIG-DB is keen to expand, data from other tropical areas are welcome. The more data available, the better we can understand the diversity and drivers of epiphytes assemblages. |
Datasets are distributed along a broad climate range, covering tropical and subtropical biomes where epiphytes typically grow, but also cold and very rainy ecoregions from the tropics (Fig. 4).
Figure 5: Density of EPIG-DB datasets across the tropics and subtropics, the heat map shows a kernel density of plots, with red colours on the most sampled areas.
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We aim at using this database, EpIG-DB, to test the generality of the findings of individual case studies to define large scale diversity patterns of epiphyte diversity. We also plan to use EpIG-DB to test general ecology diversity hypotheses of interest for the development of ecological theory and the understanding of the mechanisms underpinning diversity, not only in the tropics but also in other ecosystems.
Do you want to read about what went into the making of the paper, or why studying epiphytes is very hard! and get to know EpIG members? please visit the Journal of Vegetation Science Blog.
Current projects
At the moment there are 50 collaborators contributing with 70 epiphyte datasets. These cover 9 countries and over 20 regions. We expect that publicizing our initiative will lead to future collaborations and contributions of data to EpIG-DB, thus extending its geographical distribution.
• Can the more-individuals hypothesis (MiH) explain vascular epiphyte diversity in the Neotropics?
In the framework of the MiH we will evaluate which factors drive different aspects of epiphyte diversity and disentangle their influence across scales (Fig. 6).
We expect that predictors related to water availability (directly and indirectly) and tree structure (directly) are likely to be the most important determinants of epiphyte diversity, although their importance will vary according to the diversity aspect (species richness or abundance), taxa (e.g. orchids, ferns and aroids), and scale. |
Figure 6: Relationships between richness and abundance of vascular epiphytes and major predictors. Squares represent local (light green) and tree (dark green) scales.
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• Understanding the epiphyte – host network interaction across scales
We will characterize the epiphyte-host network, for the first time at the continental scale of the Neotropics and bioregions and will evaluate its drivers and implications for ecosystem functioning (Fig. 7).
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Figure 7: Orchid-host networks of lowlands & highlands (left section is below 800 & right section is above 2 000 m asl). Host genera are at the bottom and epiphyte species at the top.
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If you wish to contribute to EpIG-DB, consider including the following data in your epiphyte inventories:
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International Workshop on Vascular Epiphytes
We met in Marburg (Germany) from August 30th to September 1st. We were 25 scientists from Latin America and Europe. For a longer and more detailed video, please click here.
The goals accomplished were:
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