Solomon Islands’ Expedition: the ferns

During the recent expedition to central Guadalcanal in the Solomon Islands, my job was to document the ferns and lycophytes. This was at the invitation of Marika Tuiwawa (University of South Pacific) who led the expedition’s plant team. It built on my previous experience working with ferns in Fiji, New Caledonia, Australia, and New Zealand. (As well as holiday-dabbling in Tonga, Vanuatu, and Niue.)

Me, Sarah Pene (University of the South Pacific), and Shelley James (Florida Museum of Natural History) collecting plants. At the floor of a valley near base camp. Photo © Matt Renner, used with permission. — Me, Sarah Pene (University of the South Pacific), and Shelley James (Florida Museum of Natural History) collecting plants. At the floor of a valley near base camp. Photo by Matt Renner, used with permission.

See Te Papa blog posts:

Expedition to the Solomon Islands for general background.
Solomon Islands’ Expedition: the camp for living conditions.

Listen to interview about the expedition, with Radio New Zealand National.

The Solomon Islands are home to approximately 370 species of ferns and lycophytes. That’s more than any other Pacific Island group.

The Solomon Islands are a gateway between the hyperdiverse (but poorly documented) New Guinea and the other Pacific Islands to the east. Understanding the fern floras of, say, Fiji or Vanuatu, necessitates a good knowledge of the Solomon Islands. This is because most fern species on the Pacific Islands are shared across multiple countries. For example, only about 10% of the Solomon Islands’ ferns are confined there; the rest also occur naturally somewhere else.

Clusters of spore-making capsules on the underside of the frond of Pleocnemia leuzeana. This large ground fern naturally occurs both to the west and east of the Solomon Islands. Photo Leon Perrie. © Te Papa. — Clusters of spore-making capsules on the underside of the frond of *Pleocnemia leuzeana*. This large ground fern naturally occurs both to the west and east of the Solomon Islands. Photo Leon Perrie. Te Papa

There is no modern published account of the Solomon Islands’ ferns and lycophytes. However, we did have access to a draft Flora prepared by David Glenny (was with Te Papa; now at Landcare Research) while he was based in the Solomon Islands for a couple of years in the 1990s. This was a big help to us.

During our expedition, I worked with Sarah Pene (University of South Pacific). In our nine days in the field, we made 167 collections (in triplicate, with specimens for the herbarium collections of Honiara, Suva, and Te Papa). These represent about 140 species of ferns and lycophytes.

Sarah and I taking advantage of dry space under one of the sleeping tarpaulins to press and identify our fern collections. Photo courtesy of Sarah Pene.

The fern and lycophyte diversity we encountered was staggering. Our c. 140 species came from a tiny area. Our furthest collecting points were probably no more than 15 kilometres apart, and we spanned elevations between c. 700 and c. 1300 m. By comparison, all of New Zealand, including its outlying islands, is home to just 201 species.

Few scientific visits have been made to the highlands of Guadalcanal. Consequently, we pushed up the elevation records for many of the species we detected. We also found what appear to be new records of a few species for Guadalcanal and even the Solomon Islands. However, as best I can tell, we did not find any globally new species. Even so, there is still much work remaining to do with the ferns and lycophytes of Guadalcanal’s highlands, especially with Mount Popomanaseu some 1000 m higher than what we reached.

I worked through one night in order to get our fern specimens pressed so they would make the next morning’s helicopter flight to Honiara. Frogs were constant companions, calling from the dampness of the surrounding jungle. My torch light attracted all sorts of insects, including some sizeable flyers at high velocity to my head. This moth alighted more gently, on fern subsamples stored in silica gel for later DNA analysis. Photo Leon Perrie. © Te Papa. — I worked through one night in order to get our fern specimens pressed so they would make the next morning’s helicopter flight to Honiara. Frogs were constant companions, calling from the dampness of the surrounding jungle. My torch light attracted all sorts of insects, including some sizeable flyers at high velocity to my head. This moth alighted more gently, on fern subsamples stored in silica gel for later DNA analysis. Photo by Leon Perrie. Te Papa

I take photos of everything I collect, technology and weather permitting. Here I’m photographing a terrestrial Ophioglossum. Photo © Matt Renner, used with permission. — I take photos of everything I collect, technology and weather permitting. Here I’m photographing a terrestrial *Ophioglossum*. Photo by Matt Renner, used with permission.

The photos of the ferns and lycophytes that we collected should be on Te Papa’s Collections Online website within the year. In the meantime, I’m tweeting some of the more aesthetic photos.

Fern photos from recent Te Papa field work in New Caledonia and Fiji.

Finishing the drying of our plant specimens on return to Honiara. The specimens are in the presses on top, within newspaper and card. The presses are sitting on a grill, above a gas-powered burner (like you might use for campsite cooking). We had these plant-dryers with us at the Valevahalo field camp. Photo Leon Perrie. © Te Papa. — Finishing the drying of our plant specimens on return to Honiara. The specimens are in the presses on top, within newspaper and card. The presses are sitting on a grill, above a gas-powered burner (like you might use for campsite cooking). We had these plant-dryers with us at the Valevahalo field camp. Photo Leon Perrie. Te Papa

Te Papa’s WELT herbarium has a duplicate set of David Glenny’s fern and lycophyte collections from the Solomon Islands. Together with our recent specimens, it means Te Papa has one of the world’s best collections of Solomon Islands’ ferns and lycophytes. I hope to use this to improve the documentation of the Pacific’s ferns; some checklists with updated names would be a good start.