Researchers discover new plant species on recent Norfolk Island expedition

A team from the Australian Institute of Botanical Science has collected about 400 plant specimens on the recent Australian Museum-led expedition to Norfolk Island, helping the community identify new weeds that potentially could cause havoc to local ecosystems.

Botanic team on a mission to fill knowledge gaps

Norfolk Island, about 1,600km north-east of Sydney, has a diverse environment and provided a great research opportunity for a team from the Australian Institute of Botanical Science (Institute).

The Institute team’s mission was to collect herbarium specimens to help fill knowledge gaps of Norfolk Island’s flora, focusing on areas where no or few collections have been lodged in Australasian herbaria, such as the National Herbarium of New South Wales.

Although weeds are not part of Norfolk Island’s endemic and unique flora, they have the potential to threaten the local ecosystem and became a matter of interest for the researchers. The threat of Oxalis pes-caprae (Soursob), which is a very serious, pernicious weed, was of particular concern.

Senior Botanist Marco Duretto said as well as Oxalis pes-caprae, Soliva anthemifolia (Button Burweed) and Hypochaeris albiflora (White Flatweed) were provided to the team by locals and are new records for Norfolk Island. A new species of fern in the genus Blechnum was also a significant find, and may represent a new, possibly naturalised, species for the island.

While the researchers had their eyes on weeds, team member Honorary Research Associate Matt Renner collected bryophytes (mosses, liverworts and hornworts), which are his research speciality. Matt’s collections significantly expanded the knowledge of the bryophyte flora of the region with first records of families, genera, and species for the region commonplace.

All up the team made c. 400 collections (including 160 bryophytes) of c. 140 species and the numbers of species will increase as identifications are finalised, especially that of the bryophytes.

Collaborating with the community to improve conservation

The team also included Senior Technical Officer ID Counter Andrew Orme, Digitalisation Officer Mel Wong, and Plant Information Network Officer Wayne Cherry. They joined forces with the local community, the Australian Museum, Parks Australia and the Auckland War Memorial Museum in a biological survey covering many animal and plant groups.

Marco said building close contacts with the local community to develop long-term relationships was very important in helping the team to discover new flora.

“The local Flora and Fauna group on Norfolk Island has been meeting for many years and has built up a wealth of knowledge,” Marco said.

“We were lucky enough to be able to engage with some of them and hopefully form some long-term relationships so that together we can continue to build on the knowledge and understanding of Norfolk Island’s flora."

“Often scientists like us will sometimes go about our work and not connect with locals but both Museums and the Gardens were very keen to build long-term relationships with the local community.”

“This Oxalis weed is a real scary one – it’s a spectacular species and beautiful to look at – but it has underground bulbs and is a very serious weed. Once it gets into local areas it’s hard to get rid of. It forms monocultures because other things that live on the ground next to get excluded."

“Local people knew it was there, but records didn’t exist in herbaria collections, and now we have a permanent record for this species of weed on Norfolk Island. And our confirmation of the identity will help the local council take appropriate action to eradicate it before it becomes an issue,” Marco said.

Why weed knowledge is important

Weeds are very important in terms of economic and conservation impacts because they are a major threat to native flora communities.

The weeds were brought to Norfolk Island by various settlers, from Polynesians to Europeans, and many weeds are recent introductions.

Wherever people go they bring weeds with them – on their clothes, and in their equipment, and now more people are moving weeds to Norfolk Island all the time.

The weeds smother and out-compete the native plants, and once the vegetation goes, endemic plants as well as habitat for indigenous wildlife can be lost.

Marco said that Norfolk Island has many endemic species and conservation of this flora is a high priority.

“The local agriculture community might want to know it’s there because it’s a very serious weed and outcompetes grass and impacts local animals,” Marco said.

Keeping digital records

Herbarium collections provide permanent records of plants and where they were growing. They are invaluable resources, physically and electronically, that are available to the community and researchers from around the world. The collections are being imaged and these images and associated data are what the public can use.

In addition to herbarium material, the team also collected tissue samples for DNA extraction and analysis for future projects. All material, including tissue samples, will also be made available to researchers far and wide.

“Digitisation of the herbarium collections and having quick access to these images has helped research enormously. For example, 10 or 15 years ago before digitisation occurred, if I wanted to see a plant from Europe I would have to wait a year or two for it to come here as a loan,” Marco said.

“Someone may be researching any of the species we collected and might want to know where they are growing around the world. They may be working on taxonomy or on how to control a weed and so having this information is beneficial,” said Marco.

To view the original article, and to view more Stories from the Garden, please go to: https://www.rbgsyd.nsw.gov.au/stories/2022/researchers-discover-new-plant-species-on-recent-n