Studying habitats to support sustainable farming
Nature provides benefits worth billions of euros a year to EU agriculture - such as pest control by insect predators. An EU-funded project has improved knowledge of the habitats that foster these so-called ecological services, helping to support an increase in sustainable farming and food security.
© sherez #1771585 2019, source:stock.adobe.com
Ecological or ecosystem services include control of pests by their natural predators, as well as crop pollination, largely by bees and other invertebrates. Semi-natural habitats are those affected by human activity, such as hedgerows, woodland and grass strips, that foster such services.
Current farming systems rely on chemicals that may pollute semi-natural habitats and disrupt ecological services. As the expected need to meet 60 % more food demand by 2050 will require intensification of agriculture, greater knowledge of the role of these habitats could support such an increase in harmony with nature.
The EU-funded QUESSA project has quantified the actual and potential contribution of semi-natural habitats to ecosystem services mainly pest control and pollination, but also soil erosion mitigation, soil fertility, carbon sequestration in soil and biodiversity. It developed heat maps highlighting room for improvement.
One interesting finding regarding the pollinators' heat maps was that the nearby presence (ca. 100 m) of woody vegetation was associated with higher yields in open-pollinated flowers. However, large bodies of forest do not help pollination as many beneficial insects do not go deeply into forests, which is a good indicator of the agroecosystem supporting this ecosystem service, combining crops with hedgerows.
If we are to develop more sustainable farming systems and reduce reliance on agrochemicals, we need to better utilise beneficial invertebrates for pollination and pest control, especially given the decline of some invertebrate groups like insects and worms, says project coordinator John Holland of the Game and Wildlife Conservation Trust in the UK. To achieve this, we need to fill in the gaps in our understanding of these species requirements and improve existing habitats or develop new ones targeted towards beneficial invertebrates.
Honing in on habitats
QUESSAs research focused on impacts on seven crop types wheat, oilseed rape, sunflowers, pumpkins, pears, olives and vines in eight countries Estonia, France, Germany, Hungary, Italy, the Netherlands, Switzerland and the UK.
The first step entailed identification of key habitats, their vegetation composition and main ecological service providers. The habitats were given a score for their service delivery potential and methodologies were developed for measuring actual delivery, which was displayed on heat maps. QUESSA found greater potential for improving the contribution of semi-natural habitats to pest control than to pollination and no indications that semi-natural habitats cause adverse effects.
Along with information on synergies between services, landscape and farming systems, the maps supported the upscaling of models for predicting the effect of semi-natural habitats on pollination and pest-control from farm to European level and the development of a web-based tool to measure on-farm service provision.
QUESSA found that as semi-natural habitat vegetation varies between countries and types of habitat, it alone is not a suitable predictor of ecological services delivery. Also, the impact of semi-natural habitats is dependent on the type of habitat, service and landscape. Furthermore, synergy levels between ecosystem services vary according to landscape composition.
In some cases, we were able to demonstrate the beneficial effects of semi-natural habitats at field and landscape scale, but not always, says Holland. Such variation is not unexpected given the complexity and diversity of agricultural ecosystems but shows potential to better exploit ecosystem services.
To achieve this, for farmers and other stakeholders, QUESSA suggests improving soils, further investigating potential semi-natural habitat contributions to pollination, increasing their presence to facilitate delivery of multiple ecological services and improving their management, especially the proportion of flowering plants, to fully benefit from biodiversity.
For policymakers, the project recommends strengthening legislation aimed at protecting semi-natural habitats, promoting their importance and supporting the development of new, specially adapted areas of this type. Holland adds that while agri-environment funding schemes provide opportunities to develop semi-natural habitats on-farm, they need to focus more on functional biodiversity.
Finally, QUESSA also advocates revising legislation on ecological focus areas land where environmentally beneficial agricultural practices are carried out to enhance their contribution to ecosystem services.