Scientists have been documenting plant species for centuries to help us understand and protect the incredible diversity of flora in our world. But according to new research, many have never been photographed in their natural habitats — and that’s a problem.
Researchers from UNSW Sydney and the Australian Institute of Botanical Science, part of the Royal Botanic Gardens and Domain Trust, searched 33 major online plant photo databases to examine the photographic record of Australian plant species. The findings, published in Young Phytologist, reveal of the 21,077 native Australian vascular plant species, almost 20% lack verifiable photography.
Lead study author and UNSW Science PhD student Thomas Mesaglio says Australia is one of the richest areas in the world for native species.
“It was surprising to see how many plant species just had line drawings, illustrations, paintings, or even no media at all,” says Mr. Mesaglio.
Dr Hervé Sauquet, co-author of the study and senior researcher at the Australian Institute of Botanical Science, is based at the National Herbarium of New South Wales.
“All plant species ultimately rely on specimens in herbarium collections for their identification,” says Dr. Sauquet. “However, even in this digital age where most herbarium specimens have been scanned and are accessible on the web, photographs of living plants in the wild are still critically needed.”
The study’s senior author from UNSW Associate Professor of Science Will Cornwell says the lack of detailed photographs can have real consequences. Many species of plants that are difficult to identify in the wild may become extinct if scientists cannot correctly identify them with the help of photographs.
“We had assumed that every plant species would simply have been photographed by someone, somewhere, throughout history. But it turns out that’s not the case,” says A/Prof. Cornwell.
“This is where citizen scientists can come in and help us fill that gap with their photos.”
Gaps in the photo file
Photographs can help botanists and taxonomists working with plant specimens by preserving characteristics such as flower color that are lost over time in their specimens. They can also display additional features, such as leaf orientation or bark appearance, and add ecological context.
“Having a complete photographic set helps us to be confident in our identifications,” says Mr Mesaglio. “Especially when it is practically difficult to collect and preserve the whole plant, photographs supplement the physical voucher by showing the type of soil, the habitat in which it grows, and other species growing alongside it.”
But it turns out that not all plant groups are photographed equally. Just as some animals receive less attention than others, there can also be a bias against less gifted plants.
The study found that the most well-photographed groups of plants tend to be shrubs or trees with more noticeable or spectacular features, such as colorful flowers. Banksia, for example, is one of only two Australian plant genera with more than 40 species to have a complete photographic record. Meanwhile, the family with the most significant photo deficit was Poaceae — commonly known as grasses — with 343 unphotographed species.
“We’ve seen a deficit of charisma, so the genres that tend to be harder to see are the ones that lose out,” says Mr. Mesaglio. “They may have innocuous or pale flowers or be smaller and harder to spot grasses, sage and herbs.”
Geography also influenced the photographic archive. While most species in Australia’s southeastern states have complete records, Western Australia had the largest gap, with 52 percent of all unphotographed species found there.
“Australia’s main unphotographed plant hotspots are areas of great plant diversity, but the environments are rugged and often difficult to access, particularly by road,” says Mr Mesaglio. “But it means there’s an exciting opportunity to visit these sites because we might capture something that’s never been photographed before.”
Political scientist activation
It is one thing to have comprehensive photographic archives for professional scientists to use in identification guides. But when plant life is threatened on multiple fronts, including habitat clearing and climate change, photographs can help engage the public in plant science.
“People can engage, empathize and get much more excited about plants with photos, which is vital when our natural environment is more at risk than ever,” says Mr Mesaglio.
“Because digital photography is so accessible now, anyone can also help make meaningful contributions to science by using the camera in their pocket.”
Using a platform like iNaturalist, experienced citizen scientists can identify their expert snapshots and share the data with aggregators like the Atlas of Living Australia and the Global Biodiversity Information Facility for use in research and conservation.
“Since April last year, we’ve identified almost 10 per cent of these previously unphotographed species thanks to members of the public uploading their photos and experts kindly spotting them,” says Mr Mesaglio. “There could be many more in personal collections or behind paywalls waiting to be shared.”
The researchers recommend the development of a standardized system for scientific plant photography, starting with a requirement in the International Code of Plant Nomenclature to include at least one field photograph wherever possible in descriptions of new species. They also suggest that all new species descriptions be published as Open Access in searchable databases under a Creative Commons license to maximize their use.
“We also suspect that there are more photos, but they are hidden on social media or behind scientific paywalls that are not accessible, traceable or searchable,” says Mr Mesaglio.
“Of the items with photos, many have one photo. We not only want to capture these underrepresented species, but also continue to build the photographic archive for all species.
“Doing so will help us identify, monitor and preserve our native species for future generations.”