Maintaining more areas with natural vegetation ensures the presence of insect pollinators in our crops” Interview with Ainhoa Magrach and Ignasi Bartomeus

We have two very ambitious challenges: the first is to continue to grow enough food for an exponentially growing population and the second is to do so without depleting the planet’s resources. We talked about this topic with Ainhoa Magrach, researcher at the Basque Centre for Climate Change, and Ignasi Bartomeus, researcher at the Doñana Biological Station.

̶For many years, in order to produce more, the choice was made to homogenise the landscape, i.e., to reduce the variety of crops. What are the consequences?

Ignasi Bartomeus (IB): The homogenisation of the landscape is a complex process derived from globalisation and the fact that the large-scale economy encourages single-crop-producing regions. However, this often benefits entrepreneurs, but not farmers.

Ainhoa Magrach (AM): At the landscape scale we are observing how areas once covered by mosaics of different habitat types are now covered by a single habitat type, e.g., agricultural areas, which already occupy more than 40% of the ice-free land area.

There is also homogenisation at the species composition level, as many generalist species are facilitated by human impacts and are able to survive in many places at the expense of other specialists. But we also observe a homogenisation at the genetic level, and this can be observed both in the case of wild species and in crops, as fewer and fewer varieties are facilitated.

̶Is it serious to replace biodiversity with the dominance of certain crops? What awaits us if we don’t stop to rethink the way we produce food?

IB: For a long time, certain natural processes such as pollination, soil regeneration or pest control have been taken for granted, since biodiversity provided these services. However, the thousands of species that coexist with us in agricultural landscapes need minimum conditions to survive, and when we oversimplify the landscape, we lose those conditions, we lose many species, and we lose the services they were providing to us.

AM: By replacing biodiversity with a reduced number of crops, which in many cases are planted as monocultures, we increase the possibility of a pathogen affecting them. This is the case of pine trees in the Basque Country, for example, which are currently affected by a fungus that compromises the leaves and prevents them from photosynthesising. By growing in plantations of this single species, the fungus has been transmitted from tree to tree in a simple manner, something that would not occur in a wild forest where several different species would coexist, and the fungus would not be able to spread as quickly.

̶The population is growing steadily, but our resources are finite. Can biodiversity contribute to help us produce with the least possible environmental impact?

IB: It is a fallacy that the problem of feeding a growing population is the capacity to produce food. At present, enough is produced, but it is poorly distributed, and a large proportion is thrown away. Conserving biodiversity in agricultural landscapes is not only a matter of production, but also a matter of sharing space with other species.

AM: Exactly. The current problem is not so much one of production as of distribution and waste. Today we waste a great deal of food.

̶ What is the role of pollinators and why is it so essential?

IB: Flowering plants need animals to pollinate them in order to bear fruit, so pollinators, especially bees and hover flies in our latitudes, are a key element for the functioning of the planet. Many crops can bear fruit without pollinators, but often yield and fruit quality decline.

AM: 85% of wild plants and more than 70% of the crops we consume depend in some way on pollinators, i.e., the movement of pollen between different individual plants increases yields. And these pollinator-dependent crops include those that contain the highest amounts of minerals and vitamins. In many crops honeybees in hives are used to pollinate crops. However, the honeybee is not always the most efficient pollinator, and each crop has a different flower structure (i.e., size and shape).

Thinking that we can rely solely on the honeybee is like thinking we can use a Phillips screwdriver for absolutely every screw we have. It just doesn’t work in the same way. In addition, as with the pine trees of the Basque Country, this species can suffer from diseases or be affected by climate change, and having a diversity of pollinators is an insurance against possible accidents and losses.

̶ What can producers do to rebuild biodiversity?

IB: Paradoxically, many traditional practices are compatible with biodiversity. Having smaller fields, increasing the number of different crops in the landscape, respecting field boundaries and margins, and keeping less productive areas with natural vegetation ensures that thousands of insects and other animals find shelter and can coexist with us. Conserving large mammals requires large natural parks, but for many insects a few square metres of good habitat is enough to thrive.

AM: I agree. In many cases doing nothing is almost better than doing something. Naturally in many areas there are seed banks in the soil that, if allowed to grow, include many of the flowering species used by these pollinators. In addition to floral resources they need nesting areas, so having areas with wood or not removing the soil would allow different species to establish their nests based on their needs.

̶And how can we as consumers support the transformation?

IB: It is difficult to put the responsibility on consumers, because we are immersed in a system that we do not control. Consuming local, seasonal products and reducing consumption is important, but it is much more important to demand from our politicians a commitment to sustainable agriculture in the long term, especially in a context of climate change.

AM: At the individual level we can take small actions, but major changes must be made at the institutional level and at increasingly larger scales, using the latest scientific advances as the basis for decision-making.

̶What reflection would you pass on to those who read this?

IB: I think we are at an important stage because there is a clear warning sign that we may lose many species that are the result of millions of years of evolution, but we have not yet extinguished most of them. We still have time to react and use scientific knowledge to take care of all species on the planet. Ultimately, the current model encourages a few to get rich at the expense of destroying the natural legacy we have, so changing the system to empower small farmers can have positive consequences both socially and ecologically.