Diversity in Farm Landscapes Helps Wildlife, Global Study Finds

More diverse wildlife thrives on farms, benefitting both farmers and the environment, when there is variety in the agricultural landscape, a global study has found.

Specifically, the types of crops and non-crop features on farms, as well as how they are arranged, should be varied, according to research led by Nanyang Technological University, Singapore (NTU Singapore).

The optimum approach would be to grow different crops like vegetables, cereals and fruit trees on the same farm in varying field sizes and layouts, as well as have semi-natural landscape features that are not crops, like shrubs, grassy borders and strips of wildflowers.

This variety increases the number of native animal and plant species such as pollinators and predators of pests, compared to agricultural lands that have just one type of crop grown on a single, uniform landscape.

Such an improvement in biodiversity arises because variability in crops and non-crop features, creates diverse “mini habitats” for different types of wildlife.

One of the main drivers of declines in biodiversity is increased farming to raise food production, so boosting the diversity of wildlife on farmlands is key in helping the environment.

Farmers stand to gain, too, as past research suggests that better farm biodiversity could improve crop yields; for example, by encouraging more pollinators of the crops and more predators to feed on crop pests, say the researchers of the latest study published in March 2024 in Ecology Letters.

Associate Professor Eleanor Slade, from NTU’s Asian School of the Environment (ASE) and senior author of the study, said: “Our study demonstrates that maintaining diverse crop and non-crop habitats within agricultural landscapes is important for agricultural biodiversity on a global scale. This finding holds significant implications and provides valuable insights for policymakers, land managers and conservationists. By prioritising strategies that promote crop and landscape heterogeneity, stakeholders can help preserve biodiversity and also support sustainable agricultural practices.”

The scientists also believe that increasing the diversity of crop types and non-crop features within farms could be a more appealing and practical approach for farmers to contribute to biodiversity conservation than existing methods.

Wide Study Scope

The researchers analysed close to 6,400 farmlands reported in 122 previous studies conducted in 24 countries across Asia, Europe, North and South America. The wide scope of the study means its findings are more globally applicable than earlier studies, which drew conclusions largely based on North American and European countries.

The findings are relevant to a wider range of wildlife, too. Unlike past research that focussed only on specific types of animals, this study analysed many different types of wildlife including pollinators like bees, hoverflies and butterflies; predators like birds, carabid beetles and spiders; pests like aphids, plant bugs and weevils; herbaceous plants that do not have woody stems; and decomposers like dung beetles and springtails. 

By analysing all the results from the earlier studies together, the scientists found that variety in crops and non-crop landscape elements on farms consistently improved the biodiversity of vertebrates like birds and invertebrates like insects, herbaceous plants, pollinators and predators.

Some types of wildlife had more gains in biodiversity than others. Statistically, vertebrates and plants benefitted more when both crop and non-crop features were diverse, while invertebrates showed similar benefits from either the diversification of crops or other non-crop features.

Pollinators gained more from having crops and non-crop elements with more varied layouts that better link them to one another, while predators favoured higher diversity within the types of crops and non-crop features.

These positive effects on farmlands were also consistently demonstrated in both tropical and temperate environments, in annual and perennial crops, and at different spatial scales, from within a few hundred metres of the farm to an area over several kilometres beyond the farm.