|Screenshot of Turboveg v3 prototype|
Today there are about 1500 users of the software worldwide managing more than 1,5 million relevés. Turboveg can export relevés in various file formats, which is useful to enable further analysis. Support for exporting relevés as species occurrence data packaged as a Darwin Core Archive (DwC-A) was added to v2 in 2011. Guidance on how to use this feature can be found in the Turboveg User Manual.
Version 3, due to be released in 2017, will export relevés as sampling event data packaged as DwC-A - a format that more accurately reflects the original data.
Sampling event dataSampling event data derive from environmental, ecological, and natural resource investigations that follow standardized protocols for measuring and observing biodiversity. This is in contrast to opportunistic observation and collection data, which today form a significant proportion of openly accessible biodiversity data. A good example of sampling data is data coming from vegetation sampling events using the Braun-Blanquet protocol. Because the sampling methodology and sampling units are precisely described the resulting data is comparable and thus better suited for measuring trends in habitat change and climate change.
Sampling event data modelA data model provides the details of the structure of the data. Previously sampling event data couldn't be modelled in a standardized way in Darwin Core due to the complexity of encoding the underlying protocols. Over the past two years, however, GBIF has been working with EU BON and the wider bioinformatics community to develop a data model for sharing sampling event data. In March 2015 TDWG, the international body responsible for maintaining standards for the exchange of biological data, ratified changes that enabled support for modelling sampling event data.
Note additional tables of information can also be added to a Sampling event, such as Multimedia (e.g. to record images of the plot). More information about this preferred data model for sampling event data can be found in the IPT Sampling Event Data Primer.
Sampling event data model for vegetation plot dataVegetation surveys or relevés produce a wealth of information on species cover and on substrate and other abiotic features in the plot. Species cover can be measured using dozens of different vegetation abundance scales such as the Braun-Blanquet scale or Londo decimal scale to name a couple. To standardize how this information is stored, a custom Relevé table is used instead of the Measurements or Facts table.
This data model for vegetation plot data in Darwin Core consists of three tables: Sampling event, Relevé and Species Occurrence.
Example DwC-A export by Turboveg: Dutch Vegetation Database (LVD)Fortunately, the Dutch Vegetation Database (LVD) has recently been republished using the new sampling event format and can thus serve as an exemplar dataset. LVD is a substantial dataset published by Alterra (a major Dutch research institute) that covers all plant communities in the Netherlands with more than 85 years of vegetation recording for some habitats. The latest version of this dataset has more than 650 thousand relevés associated with almost 12 million species occurrences.
Alterra uses Turboveg v3 to manage this dataset and export it in the standardized DwC-A format. It is important to note that special care is taken by the software to protect sensitive species: the location of plots, which have red list species observed in them, are obfuscated to a level of 5x5 km squares. Furthermore the software converts all coverage values to the same unit (e.g. species coverage values are converted into percentage coverage) in order to make the data easy to use and integrate with other sources.
Sampling event data on GBIF.org: Dutch Vegetation Database (LVD)
|GBIF.org map of LVD georeferenced data|