Plait moss (Hypnum cuppressiforme), may be one of the most common moss types on earth but Lincoln University post-graduate ecology student, Rebecca Dollery is hopeful it may hold the key to successful germination of key plant species found in Ngāi Tahu Farming kānuka reserves.
Hypnum cupressiforme, the cypress-leaved plait moss or hypnum moss, is a common and widespread species of moss belonging to the genus Hypnum. It is found in all continents except Antarctica and occurs in a wide variety of habitats and climatic zones. All the same, Rebecca was surprised to find it in abundance in the remnant kānuka stands at Te Whenua Hou, in what is essentially a dry plains environment.
“When we first planned the biodiversity programme we were unsure of which species to plant in restoration areas,” says Rebecca.
“That prompted an in-depth study of nearby reserves and remnant kānuka stands at Te Whenua Hou that had not been touched for 50-100 years. I took soil samples and I was surprised to discover that soil in those areas was as wet as soil under the irrigation pivots, and that a thick layer of moss was well established.”
Her resulting doctorate studies have focussed on determining the importance of that moss to the kānuka ecosystem – what role it plays in seed germination, whether or not it acts as ‘a blanket’ to retain moisture and inhibit weed growth; and whether it can be restored along with key vascular plant species. She is also looking at the chemistry of moss to study the nutrients it gets from the air and how those might be of use to other plants in the ecosystem when the moss decomposes.
But it is the fact that, in a harsh, dry, stony habitat, the moss appears to be acting like “a growing blanket,” that most interests Rebecca.
“I have a series of experiments underway in the campus greenhouses, looking at different plants and whether seeds germinate and establish in moss. At the moment they’re certainly germinating more readily than they do onsite.
“I’ve been doing trials on Pomaderris (Pomaderris amoena), one of the rarer plants at Te Whenua Hou and I’ve discovered I have to heat the seed to 105-degC in an oven before it will germinate – and I have a 40% germination success rate in the incubator versus an 80% success in moss germination. That’s very promising,” she says.
“The ultimate goal of course, is to find an efficient and cost-effective way for Ngāi Tahu to restore these pockets of native vegetation. In traditional restoration, seeds are geminated and grown at a nursery before they are put in the ground. That costs money and then a lot of time and money is also spent on maintaining the reserves.
“I’m looking for a holistic restoration project where you Put all the components of the habitat together and you let them do their own thing. It’s a system with far less intervention and to achieve that we need vascular and non-vascular plants (like mosses), which appear to be important to the hydrology and chemistry of an area.”
Rebecca has planted out one reserve area with young plants (kānuka, Pomaderris and prickly mingimingi [Leptecophylla juniperina]), protected by a thick moss mat inside Combiguards. She intends monitoring those for a year but already the trial is looking promising.
“I just have to find the best way of integrating the moss,” she says.
She is also gathering forest floor litter from nearby forest stands at Eyrewell, which will be spread across reserve ground and planted out with new native trees,
“I’m lucky I can harvest ‘the whole forest floor’ for this research and even a fragment of moss included in that will grow in the new habitat. The litter contains all the right microbes to assist plant growth so I’m hoping the trial will go well.”
Her current experiments are due to be completed at the end of 2016, by which time Rebecca hopes to have established a growing technique that can be applied to any reserve on the Ngāi Tahu Farming properties.
“I’d like to come up with a method that is easy, efficient and cost-effective so that if any farmer wants to undertake an economically viable restoration project they can. That’s a big driver for me and I’m committed to it.
“I hope that this research will ultimately help farmers to create a better environment aesthetically; and that other research into soil structure and nitrogen-fixing plants may help minimise the impacts of any nitrate leaching. Introducing biodiversity may also enhance carbon credits, as there is research to show that kānuka in particular does take up a lot of carbon.”
She says there are also potential business opportunities associated with mānuka and kānuka stands – honey, oils or firewood for instance; and with the scale of the Te Whenua Hou farms, it is possible to create a chain of reserves linking the mountains to the sea, providing ‘stepping stones’ for birds, lizards and insects.
For Ngāi Tahu Farming chief executive Andrew Priest, the biodiversity partnership with Lincoln University is working so well.
“This is an important part of the “Natural Environment” pou within Ngai Tahu Farming’s quadruple bottom line strategy and reporting, and we’ve very excited about the potential for some of this research,” he says.