The drive for greater productivity in agriculture has led to an unprecedented level of food security for much of the world.
But according to an article published by the journal Nature in September, that has come at the expense of environmental stability, making it more difficult to sustain high productivity.
Why it matters: Biodiversity loss negatively affects farming systems over time. Experts say improving biodiversity would make agricultural systems more resilient and potentially less expensive for farmers.
The authors say future agricultural systems must account for this trade-off and address humans’ historical tendency to prioritize production above all else.
The article, “The productivity-stability trade-off in global food systems”, analyzes a wide breadth of humans’ historical management of food systems, and how changes in management affected the size and diversity of organisms in land and aquatic environments.
It then looks at how food webs — all the food chains in a single ecosystem — changed as a result. With the addition of results from a swath of large-scale ecological studies, the authors conclude the drive for production has led to the homogenization of landscapes, and caused greater fluctuation within food webs that threaten the environmental stability that supports high agricultural production.
Marie Gutgesell, a post-doctoral researcher working with Alaska’s Forest Service, contributed to the article while studying how agriculture influences food webs during her time at the University of Guelph.
The article’s take-away message, she says, is that environmental heterogeneity has to be considered in the pursuit of future production systems. She says there is need to think in terms of systems, rather than linear solutions and individual production challenges.
“Let’s say a common issue that might be increasingly frequent is more drought conditions. Traditionally, crops might be irrigated more. That’s a cost to the farmer. But if you can restore the capacity for soils to hold more water with perennial crops, or adjacent land that can capture more water, then it might reduce the amount of irrigation input that you might have to use,” says Gutgesell.
“Are there ways that could be mutually beneficial, where you can buffer your production against environmental vulnerability? The [article] isn’t a call to say not to produce as much food. But on a larger landscape scale, how do we mitigate that stability loss?
“This doesn’t have to involve giant changes to have a significant impact. Is there a portion of a property that can be repurposed? You get more people to do that, then it starts to have an impact at the larger landscape scale.”
Recognizing the problem
For Kevin McCann, another contributing author and professor in the University of Guelph’s integrative biology department, the article is part of a wider conversation about biodiversity and resilience “around and on the field,” and a recognition that large-scale conventional farming systems do have significant cascading effects across ecosystems.
“When you homogenize a landscape, you basically change the structure that nature is operating around. What we do in farming, it creates one energy pathway for a food web. In natural systems, that’s not how it goes,” says McCann.
“What we’re really doing in our drive to maximize productivity, we’ve driven this massive instability in the system that exists on the field and adjacent to the field. And a similar thing in fisheries as well … Over decades, suddenly you’re in a position where you’re throwing on a ton of pesticides and fertilizer to maintain the system. That’s the cost of instability.
“We’ve got to think about this as nature being a really highly connected system. What we do on the fields ends up in lakes and oceans. An action 100 kilometres away can cause a dead zone in Lake Erie.”
Some of the article’s conclusions may seem obvious – the idea that farming indeed affects natural ecosystems, for example. However, Gutgesell and McCann argue landscape-level thinking is still not reflected in the way many people, organizations and governments think about environmental problems.
Part of the challenge from McCann’s perspective is people interested in making environmental gains – improving water quality, for example – don’t readily communicate with agriculture or fishery ministries, agriculture groups, and others whose input is vital for developing an effective strategic plan to address the issue in question.
The slow pace of environmental degradation also makes biodiversity loss hard to see in real time, so it is challenging to convince people there is a real problem.
However, McCann reiterates that a critical first step is recognizing that biodiversity loss is real. If biodiversity improvements are pursued strategically, and on a landscape-scale, farmers would also see production benefits.