Dr Sara Kross, a University of Canterbury senior lecturer, is leading research into how native hedgerows and shelterbelts on farms could help boost biodiversity.
Dr Sara Kross, a University of Canterbury senior lecturer, is leading research into how native hedgerows and shelterbelts on farms could help boost biodiversity.
Canterbury researchers are exploring how planting native shelterbelts and hedgerows on farms could deliver biodiversity benefits and make good business sense.
While stands of weather-worn macrocarpa and pine are still a common sight in rural Canterbury, a growing number of farmers are planting native trees on their land.
Conservation biologist Dr Sara Kross is leading a series of projects aimed at better understanding this trend.
Kross is a senior lecturer in the School of Biological Sciences at Te Whare Wānanga o Waitaha University of Canterbury.
Her team is investigating how the conservation and rewilding potential of increased native planting can coexist alongside the commercial imperatives of farming.
Non-crop planting features such as shelterbelts, hedgerows, and bush blocks are of particular interest to the researchers.
“These features provide shelter for crops and livestock, as well as preventing erosion and runoff,” Kross said.
“But they’re also important for biodiversity and because those habitats exist at the field margin there’s a lot more interaction with the farmland and the way it’s managed.”
Kross sees huge potential for farmers to assist in the establishment of green corridors of native plantings across Canterbury.
These pathways of habitats can provide food, water, nesting, breeding, and migration sites for native species including birds, lizards, and invertebrates.
While this could significantly improve biodiversity on the plains, Kross acknowledged this goal could be at odds with the commercial side of farming.
“Most farmers are really passionate stewards of their land and want to leave it in better condition,” she said.
“At the same time, their farms are businesses and that creates a hierarchy of needs.”
She hoped the new research would show that improving biodiversity and meeting economic goals needn’t be mutually exclusive.
Encouragingly, similar research from around the world has shown an overall positive impact for farmers who develop native habitats on farm margins.
“There aren’t just ethical or aesthetic reasons to plant natives,” Kross said.
“It has the potential to deliver real production and financial benefits in the long run.”
While it’s not currently known how much Canterbury land is planted in non-crop features, an early part of the research will involve University of Canterbury PhD student Mary Buford Turnage using remote sensing technology to map existing plantings.
This hedgerow is a mix of native and exotic plantings. Photo / Hayden Oliver
“We’re hoping to use methods that will allow us to differentiate between the native hedgerows and the exotic shelterbelts,” Kross said.
“That will also help us to see where the gaps are and to map connectivity.”
Several plant nurseries now specialise in advising farmers in the choice of natives to suit their requirements.
Dairy farmers might select low-growing natives like flaxes, coprosmas or pōhuehue (muehlenbeckia) for hedgerows in the centre of pasture, so that pivot irrigators can move across them.
Fast-growing natives can be used for shelterbelts at the edges of fields, to provide weather protection for stock and to enable slower-growing natives to become established.
Though their research is still in the early stages, Kross’ team has already discovered some farmers who want to bring native birdsong back to the plains.
