Eco-buffers | Dense tree and shrub system is designed to trap more snow, improve yields and provide habitat for bees, insects and birds
Shelterbelts are getting more complicated.
Called eco-buffers, they are a complex tree system that encourages biodiversity.
This new approach to shelterbelts involves planting two to seven rows of trees and shrubs in a narrow, dense arrangement.
The goal is to quickly establish a concentrated group of plants that models a natural hedgerow. The trees and shrubs should be native to the region, chosen specifically for the site and include a variety of species with diverse characteristics.
Planting around established shelterbelts, riparian areas, wetlands and sloughs is recommended.
Don Ruzicka is experimenting with eco-buffers on his 800 acre organic farm near Killam, Alta.
He was approached by agrofrestry specialists with Agriculture Canada’s agri-environment services branch, who helped him choose a suitable location for the experiment.
Ruzicka began working the field and adding mulch last April.
Agro forestry specialists Gary Bank and Mark Wonneck, along with their crew of five, started planting by hand May 10. It took less than a day to plant four 100-metre east to-west eco-buffers 10 metres apart.
Layers of trees and shrubs were planted first and the spaces were then filled in to complete the intended design.
Shade tolerant plants were planted on the north side of the eco-buffer and sun loving plants on the south side.
Varying heights and clumping of tall and short trees and shrubs were used to maximize structural and plant diversity.
Small areas on the south side either have no plants or only shrubs and herbs. This is intended to create hot areas and bare soil areas that can be used for nesting.
The biggest and most complex eco-buffer is 12 metres wide and comprises seven rows of 41 species of trees, shrubs, herbaceous plants, berry bushes and native flowers.
Another eco-buffer is six metres wide and features three rows of 12 species of trees and shrubs, while the smallest is three metres wide and comprises two rows. It is a monoculture of berry bushes.
Bank and Wonneck will monitor the project over the next five to 10 years, specifically during the spring and summer, to see which of the three eco-buffers attract the most pollinators and the largest variety of insects and birds.
Eco-buffers first caught on in Europe, particularly in the Netherlands, where they’re grown to foster diversity. Creating and designing them on the Prairies grew out of a need for functionality.
Bank said the key question behind the research was determining the types of tree systems that could optimize farm survival under changing circumstances.
He wanted systems that would stand up to longer periods of drought and pestilence, reduce energy reliance, increase pollination and be less dependent on large amounts of inputs.
Bank’s solution was to produce more complex systems, which matched natural systems.
“So more complex equals more biodiversity. Farmers should learn to recognize that and leverage biodiversity so that they can have more resilient systems,” he said.
“Thus, this idea of farming systems that mimics more natural systems and shelterbelts that became more diverse.”
Bank encouraged farmers to think outside the box.
“If you’re in a system where you’re farming wall to wall, then the bush gets in the way. But another way of looking at agriculture is, we need these natural areas to help the agriculture proceed and survive, that it will take benefit of these natural ecosystems services,” he said.
“I call this stacking the benefits of shelterbelts.”
Bank said the typical single and double row shelterbelt traps snow and increases yields by 10 to 20 percent, depending on the crop. The eco-buffer should raise those percentages.
One of the key areas that Bank is studying on Ruzicka’s farm is the effect of the natural habitat in the eco-buffer on the presence of wild bees.
He will measure the amount of pollinated stigma in canola at the edge of the field, in the middle of field and close to the natural pollinators.
“Most literature reports that canola yields will increase between 10 and 30 and some as much as 50 percent through additional pollination from wild bees,” he said.
Building more complex vegetative areas has other benefits as well.
Bank thinks nutrient cycling of nitrogen and phosphorus should become more available to adjacent crops.
Pest suppression is also important by increasing the number of birds and insects, particularly carnivorous pest-eating beetles.
It’s important to know what a eco-buffer is expected to achieve before designing it.
“I think you’ll get more than one thing, always,” he said. “It’s just trying to strike the right balance. “
He said more farmers are looking for shelterbelts that are closer to ecological integrity. The eco-buffer may be the answer because it allows them to reduce their economic risk by lowering their input costs and producing a wider range of products.
“We’re finding that there’s a group of farmers emerging who are very interested in this kind of work and we’re responding to that. Not everybody wants a 50 quarter section with six quarter section fields,” he said.
“They may be growing wheat but they may be growing vegetables in the shade, or they may be growing alfalfa where they get assured pollination from leaf cutter bees. They may harvest the berries from these kinds of shelterbelts because they will be organic by nature. They might be able to get some of their fuel from these things (biomass) if we design them the right way.”
Bank said he sees tremendous potential for eco-buffer designs on large farms.
“Is it better to have two rows or six rows every half mile or one mile for these people, and shelterbelts that would work within their riparian areas (places they can’t farm)?” he said. “There’s a range of products you can get from shelterbelts that are properly designed. You, as a farmer, can customize it: I want a lot of timber out of this one, I want a lot of fibre for fuel, or I want berries, or I want pollination services.”
Bank said more research is needed.
“There’s a lot of science out there that suggest this will work, but we haven’t proven that it will work this way,” he said.
“We’re very interested in testing these different designs and what’s both effective and economic. We want to get there at some point. We may get all these services, but we find that this is too expensive to do or too hard to do.”
Two more eco-buffers are planned on Ruzicka’s farm this spring. He said experiences like these help him become more intimate with the land.
“We are slowly figuring out where everything belongs and why,” he said. “Well known biologist E.O. Wilson claims that ‘the more diversity that there is in an ecosystem, the more able that it is to survive droughts and other environmental challenges.’ I couldn’t agree more.”