Demonstrating the potential of iNaturalist as a tool for scientific curation to maintain the value of herbarium collections
As the saying goes, teamwork makes the dream work; and what a team (community) iNaturalist is!
By Ashton Welcome and Kamogelo Langa
Dried, pressed plants, better known as herbarium specimens have been used to describe, name and classify species for thousands of years. These specimens are heavily relied on when conducting taxonomic revisions of genera. They are used to describe species by carefully studying each character and they are also used to determine useful characters to distinguish between closely related species. The individual localities of each specimen are also used to produce distribution maps of species.
Not only have they been used for taxonomic research; but digitized herbarium data have also been used for other studies.
These studies include the mapping out of vegetation types, or determining habitat changes over time; since each specimen is time-stamped and represents a specific area at a specific time. This is important when it comes to determining threatened species as well as the invasion potential of alien species.
Herbarium specimen data have also been overlapped with the distribution ranges of cultural groups to determine which species are available to be used by each group (read more about it here). The many uses of herbarium data are still being discovered and many interesting and important studies are possible because of this data.
For this digitized data to be useful however, it is important that they are based on specimens that have been correctly identified and georeferenced.
Georeferencing is simply the process of ensuring that the locality noted on a specimen is correctly plotted on a map. With free software such as QGIS and google maps, as well as different map layers and plugins that can assist with correctly locating a point on the map; georeferencing has become a mostly straightforward task, although very time-consuming.
Accurately identifying a specimen to species level however is not always that straightforward and usually requires some level of taxonomic expertise. In recent times, taxonomic expertise has been decreasing at a rapid rate and has even been coined as the taxonomic impediment. Museums and herbaria worldwide are experiencing a reduction in trained staff and funds which will ultimately affect the quality of the collections as well as their usefulness over time. In the JRAU or University of Johannesburg herbarium there is no full-time curator or herbarium technician. It is therefore necessary to determine if tools such as iNaturalist can assist with scientific curation tasks to ensure that the collection is well curated over time.
iNaturalist is a citizen scientist platform where people share and identify observations. You simply need to upload a few photos of the specimen you found in the field and plot it on the map and then wait for others to comment on it with a suggested identification. The more agreements there are with the suggested identification, the higher the confidence level is in the identification. These observations also contribute to many different projects and therefore become a research resource.
As a small research project, we decided to determine if iNaturalist could be used as a tool for scientific curation, by uploading images of herbarium specimens along with their distribution data and then waiting for identification suggestions from the iNat community.
We selected the Hermannia collection in the JRAU herbarium to conduct this study, because there was one specific specimen which was collected in 2015 on a field trip in the Minwater region in the Western Cape. This specimen was collected during an ethnobotanical survey conducted by Dr. Margaret Hulley and Prof. Ben-Erik Van Wyk which I was lucky to join in on. The nature guide Louis Jordaan informed us that the specimen was an edible species which went by the name jakkalskos (translated into “jackals food” in English).
Along with the specimen of jakkalskos, there are 21 specimens of Hermannia in the JRAU collection. These specimens were all scanned and the collection information was recorded in an excel spreadsheet (we recorded the collector and collector number as well as the date it was collected and where it was collected).
The accurate coordinates as well as screen grabs of parts of the scanned images (close ups of the stem, leaves, stipules, flowers and flower bracts) were used for the iNaturalist observations along with newly allocated barcodes (because there were no allocated barcodes since the collection is yet to be digitized).
Barcodes or accession numbers are unique identifiers which allow us to keep track of information relating to specific specimens and will ensure that any name changes on iNat will stay connected to the correct specimen.
It can take from a few minutes to a few hours before you get citizen scientists making suggestions about the identification of your observations and it is usually a quick process. In our case, we found that we did not get any suggestions for a few days and this could be due to the fact that our observations were backdated to accurately represent when the specimen was collected.
Using iNaturalist as a tool for scientific curation is great for smaller herbaria since these collections do not always have many specimens of the same species. Having more than one specimen of a species allows for comparisons to confirm identifications.
Not only could we rely on the iNaturalist community to assist with scientific curation, but we could also use the platform ourselves. We soon discovered that our unknown jakkalskos was in fact Hermannia pulverata; also known as the little brown Hermannia. And to our surprise, there was no food plant record for this species in literature and also no reference to the common name jakkalskos. This however did not surprise the nature guide Louis Jordaan from Minwater, as he said that there are many species which he himself enjoys eating that have never been recorded in literature.
This project not only revealed new dimensions of an already wonderful species but it brought to light, the value of herbarium collections as well as the value of iNaturalist.
This project was conducted by an honours student by the name of Kamogelo Langa at the University of Johannesburg under my supervision. I am so proud of her hard work and the enthusiasm that she brought to this work!
It is still in its very early stages, but please follow us on iNaturalist here and comment and suggest ID’s as we go along :) thank you!
