How this flower can tell us more about the Nova Scotian sand barrels

Researchers from Acadia University have completed a study on rockrose, a critically imperiled plant species from the sand barrels of the Annapolis Valley.

Rockrose, also known as Canada frostweed, grows in dry, sandy and acidic soil. But its natural habitat has been reduced by 97 per cent due to agriculture, transportation and housing developments, leading to massive population decline.

Kendra Sampson of Acadia’s KC Irving Environmental Science Center, who led the research, said she obtained seeds and sand from the plant’s natural habitat and used them for propagation in the lab.

“This plant is a small piece of a larger picture,” said Sampson. “We look at some individual plants, but they all make up the big goal of the mandate of maintaining biodiversity in these ecosystems.”

The study found a type of fungus, arbuscular mycorrhizal fungi, formed mutually beneficial relationships with the plant’s roots, aiding it in absorbing water and nutrients in the acidic soils of sand barrels.

Kendra Sampson’s research was part of her honors study at Acadia University. She now works at the KC Irving Environmental Science Center. (Cassia Lawrence)

“(AMF) form a root-like structure that’s much smaller in diameter than plant roots,” she said. “It extends much further into the soil and can gather up nutrients for the plants, so phosphorus or nitrogen, even acquire water for the plants.”

Sampson hopes the study will assist conservationists in gaining a better understanding of the connections between species in the sand barrels and how the preservation of one species could benefit all the others.

She said the specimens she grew in the lab could be planted back into the wild, and the fungi could be used as a green alternative to fertilizers.

After sterilizing the seeds, Sampson and her team inserted them into a jelly-like subtract called tissue culture, which is full of nutrients. Then they propagated them to have multiple specimens (Craig Paisley/CBC)

The sand barrels in Annapolis Valley are extremely delicate ecosystems that depend on naturally occurring forest fires to clear tall vegetation.

The species that live there exchange nutrient-rich soil for bright sunshine, which is why AMF is important to any plants growing in this sandy, acidic soil, Sampson said.

Alain Belliveau, collections manager at Acadia’s EC Smith Herbarium, was part of a team of specialists that developed the Nova Scotia Recovery Plan for the Rockrose in 2021.

He has been monitoring the plant and surveying its population trends every couple of years to get a sense of how the sand barrels are doing.

“A big part of it is that these plants, what we call species at risk, represent the type of the iceberg,” Belliveau said.

“The rockrose is so rare and so threatened that we look at it as representing the ecosystem as a whole.”

Rockrose helps the sand barren ecosystem by filtering water and providing a habitat for local wildlife. (Craig Paisley/CBC)

Belliveau hopes more studies like this will improve their conservation efforts for the rockrose and other at-risk species in the ever-rarer Nova Scotia sand barrels.

He said he would like to see the provincial government, universities and non-profits investing in more research as they are struggling to secure funding and staff.

“There’s a lot of work ahead,” he said.

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