Meristem: Crop Science

Ask many producers the value they place on patches of natural remnant vegetation on their land and chances are they'd simply say they haven't given it much thought. If they have, there's a good chance some would think of them as sources of crop pests or obstacles that could easily be removed to streamline the cropping process.

But is there more to these sites – which include wetlands, natural shelterbelts, road allowances and other natural areas that have not been developed for agricultural or industrial use – than something that gets in the way of systemized cropping? That's the question posed by Kim Schmitt, director of Natural Advantage, a planning service which helps Alberta farmers and ranchers manage wildlife habitat resources on their operations.

"The loss of bee populations across North America has been a wake-up call on how the loss of one key element in the ecosystem can have a far-reaching impact that filters down to producers' own bottom lines," he says. "A big question is the level of risk we are assuming by not proactively conserving natural areas and remnant vegetation in the agricultural landscape. For example, how much do we really know about the relationship between remnant habitats, insects and agricultural production?"

Perhaps the first step toward answering those questions, says Dan Johnson, a professor of environmental science at the University of Lethbridge and a prominent researcher in the field of sustainable grassland ecosystems, is dropping the general misconception that nature is simple.

"Nature is variable, quite messy, and more wired together than highly balanced. But we're seeing that if we can identify some general patterns, there may be some rules of thumb that can be used for telling pests from non-pests, getting the most from the beneficial species, and for managing remnant areas, not only for sustainability, but for the real economic benefits that they can provide."

Lessons from bee losses

Farmers tend to think in terms of the bottom line and any discussion of natural habitat value to cropping systems may seem theoretical. Benefits of on-farm wildlife habitat can take a long time to appear and may not seem to be as economically gratifying as converting it to farmland.

Perhaps the clearest example of the importance of wildlife habitat to agriculture, however, lies in the recent, unexplained phenomenon of declining bee populations in North America. According to a recent article in Reader's Digest ("What's Happening to the Bees?" July 2008, pg. 92), the pollination services honeybees supply are worth between $1 billion and $2 billion a year and account for one of every three bites in the average Canadian meal.

As a canola producer whose production success is directly tied to the pollination activity of bees, Harry Schudlo of Rycroft, Alberta understands this connection. "I don't know if we can afford to take the chance of destroying remnant habitats. I really believe many producers are taking bees for granted and the role they play in cross-pollination and in the production of other flowering vegetation."

Taking this into account, maintaining natural vegetation may be of more value than currently thought, says Schmitt. "We know, for example, that native lands with plants with overlapping bloom times in their habitat may help bees thrive in the monoculture of agricultural crops. Perhaps consistent care of these areas and using more integrated management practices may be of broader benefit."

Benefits of insects

There are some strong but highly variable relationships geographically and year-by-year between remnant habitats and insects, says Johnson. Despite some popular misconceptions, however, their value is more often positive than negative.

"In general, it's been found that, more often than harbouring pests, natural vegetation will harbour the natural enemies of pests - for example, spiders or tiny wasps that attack the eggs of pest species," he says. "They also provide habitat for native pollinators such as bees; soil fertility contributors; decomposers that do the job of removing carrion and breaking up dead vegetation; and other contributors to ecological processes."

However, when producers see large populations of grasshoppers in the field, remnant vegetation areas such as shelterbelts or "unimproved" pastures are often singled out as the source. Johnson says the question is whether the grasshoppers the farmer is seeing are pests, as not all grasshopper species consume crops to the same extent, or even at all.

"Some people say grasshoppers hide out in remnant areas and then come back, and this can happen in rare years. But in most cases the grasshoppers they see in remnant areas are rarely the pest species. In fact, many of the grasshopper species found in remnants and shelterbelts do no damage and simply support birds and the parasites and diseases that attack insects, and these natural enemies may even offer some help when the pests return. But granted, in a rare outbreak year, pests may be everywhere," says Johnson.

It's also important to remember that, in those rare instances in which remnant areas provide habitat for pest species, that it's not always a bad thing from a resistance perspective, says Johnson. "There are cases in which some pest refuge populations that have not been subjected to insecticides are actually good for slowing down the acquisition of insecticide resistance."

A resource for decision-making

In many cases, putting management practices in place requires a connection to a greater level of scientific and technical knowledge than many farmers possess. That's why Natural Advantage: The On-Farm Wildlife and Biodiversity Planning Service has been developed as a free service for Alberta producers. In 2007, the pilot version of the service quickly sold out with 62 farms and ranches covering over 90,000 acres across the province filling available spots.

Offered by Ducks Unlimited Canada (DUC), the Natural Advantage process starts by signing a simple letter of understanding which outlines to producers in straightforward terms how the work is carried out. From that point, trained biologists from DUC analyze the habitat resources on the property and conduct a phone interview to discuss the project with the participant.

Habitat areas are then analyzed and classified using aerial photography and Geographic Information System (GIS) mapping. Biologists then spend up to half a day meeting with the landowner to discuss their findings, also taking time to complete field verification and a rapid assessment of the condition of the areas identified.

The final product for producers is a comprehensive written report on the knowledge gathered, including resource materials and contact information to assist with implementing the report's recommendations. "Last year, the majority of responses indicated that clients were most impressed with the information and professionalism of the final personal report, with several saying that it exceeded their expectations," says Schmitt. "The 2008 program year is approximately two-thirds filled for this year so now is a good time to sign up."

Farmers can sign up for the Natural Advantage program by contacting DUC biologist Julie Pierce toll-free at 1-866-479-3825 or 780-930-1255 or by email at j_pierce@ducks.ca. Kim Schmitt can be reached by e-mail at or by phone at (403) 342-1314. Dan Johnson can be contacted at the University of Lethbridge at (403) 329-2040 or .

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Natural habitat remnants and native insects

Lessons from bee losses

Benefits of insects

A resource for decision-making