Biodiversity is vitally important. We read and hear a lot about it and in particular that things are not going well. In a series of articles, we will investigate what exactly is going on and how farmers in the peat meadow area can contribute positively to biodiversity. But we start with the question: what do we actually mean by ‘biodiversity’ and what does it have to do with agriculture?
More than “many species”
Is biodiversity everything to do with nature? To have as many different species as possible in an area? Everyone has their own association with the term biodiversity. Yet it is a multifaceted and complex concept. “Biodiversity is much more than the number of species. It is also, for example, about the variation within a species, the genetic variation,” stresses Louise Vet, professor of ecology at Wageningen University & Research. Louise is indirectly involved in the work of Wij.land through her position on the board of Commonland, and as chairwoman of the Delta Plan for Biodiversity Restoration, she works with nature organisations, farmers, citizens, knowledge institutions, governments and businesses to restore biodiversity in the Netherlands.
“Biodiversity is also about the function of species within an ecosystem and the variation therein,” she continues. “The interaction between species determines what function a species can fulfil in a system. Biodiversity, therefore, ranges from the smallest molecular level to the level of the landscape. It is the versatility of life in all its forms.”
The official definition of biodiversity – as formulated at the United Nations Convention on Biological Diversity in 1992 – is:
“The variability among living organisms from all sources including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.”
Many people now know that biodiversity in the Netherlands is not doing well. That is also the case in the countryside, according to Vet. “If you just look at the landscape, we have lost a lot of variety. Everything has been straightened out, and so we have lost the small scale and the changes in the landscape. Hedges, groves, ditches and streams have disappeared, and with them a lot of species for which it was a habitat.”
But also in agricultural plants and animals, a lot of variation has disappeared – right down to the genetic level. “In the past, all farmers had a mixed farm and there was a lot of variation in the plants and animals they worked with. Slowly but surely, farmers have started to specialise and now all farmers work with the same breeds of animals and the same breeds of grain, etc. That also brings risks, for example, that diseases can spread quickly within a farm and also quickly spread to other farms.”
More and more farmers want to contribute to the restoration of biodiversity. A good start is the restoration of soil life. But even then, the question is at what scale level you should look at biodiversity. Do you only look at what lives in your own meadow? Or do you look at the contribution of your land to the ecosystem of the surrounding area? Joachim Deru, a researcher in agrobiodiversity at the Louis Bolk Institute, also noticed the difference. He studied how farmers in the peat meadow area can contribute to soil biodiversity, from earthworms to small springtails, mites and nematodes.
Joachim studied twenty agricultural plots and twenty natural grasslands. Surprisingly, it turned out that more different species were present in the soil on an average agricultural plot. The number of earthworms was also higher. “Agricultural fields are fertilised with animal manure and that is food for the soil life,” Joachim explains the surprising result. “Also, aeration is often better; natural grasslands are less drained, so the soil is also colder in the spring and soil life gets going later.”
Yet the picture is different if you look at biodiversity in a different way and analyse the same figures differently. It is true that an agricultural plot has more species per plot on average, but if you take the biodiversity of all the agricultural grasslands studied and do the same for the natural grasslands, the natural grasslands come out better. “The natural grasslands differ much more in terms of species composition, so altogether there is more diversity. The agricultural plots are all similar, so the sum total is lower. So it makes a big difference at which scale level you look at biodiversity.”
Combining nature and agriculture
Deru also investigated what soil life, and especially worms, delivers to meadow birds. Fertilisation, especially with a good ratio of separated manure, appeared to have a positive effect on the number of earthworms, and thus on the food for meadow birds. But meadow birds need more than just earthworms. Farmers in the research area indicated that many meadow birds nest in the natural grasslands. There is plenty of shelter and food in the form of insects for the young. But the adult birds come to get worms in the fertilized fields. Therefore, Deru concludes that the overall biodiversity would probably benefit from a combination of agricultural and natural grounds, preferably in a varied mosaic.
Natuurmonumenten also recognises this. The nature organisation itself manages valuable marshes, peat moss reed lands and bogs, but it also has a large number of natural grasslands in the peat meadow area that are used and managed by tenants. These agriculturally used nature lands are also very important for biodiversity, according to Baukje Sijtsma, ecologist at Natuurmonumenten. “It is important to realise that the landscape in the peat meadow area was almost entirely created by human hands, including many of the nature areas that we now manage ourselves. The meagre grasslands were once created by people mowing them or allowing them to be grazed,” says Baukje.
From tenant to farmer
Until the middle of the last century, all farmland was rich in species. The land was used less intensively, it was much more flowery and therefore richer in insects and birds. Together with their agricultural tenants, Natuurmonumenten is trying to regain some of this biodiversity. In recent years, this was done in the project “From tenant to partner“, which was supervised by Wij.land. “We really entered into a dialogue with the farmers to develop the cooperation even further and to make the grasslands even more part of the nature reserve. Together, we went into the field to see how the nature value could be further increased, but also to see what works well for the farmer’s business. There is a National Nature Network of nature areas, but that is not enough. To preserve biodiversity, we need farmland to be part of it.”
Transitional areas are critical
Farmers can, to a greater or lesser extent, adjust their operations to benefit biodiversity. Louise is enthusiastic about the three-zone approach of Commonland and Wij.land, which is based on a mixed zone between nature areas and real production land. “In the Netherlands, we have quite a lot of agricultural land next to nature areas; you can’t draw a hard line there. You have to pay more attention to biodiversity in those agricultural areas and the influence of agriculture on the neighbouring nature area. But working more nature-inclusively also applies in the agro-zone, biodiversity is something we all have to work on.”
How can farmers concretely contribute to biodiversity and what successes are already being achieved? You can read that in the next article in this series on biodiversity.