Increase crop diversity across a farm or farmed landscape

Overall effectiveness category Awaiting assessment
Number of studies: 2
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How is the evidence assessed?

Effectiveness

not assessed
Certainty

not assessed
Harms

not assessed

Calculating overall effectiveness category

Background information and definitions

Agricultural landscapes are often homogenous, with the same crops being grown across a large area. Increasing the diversity of crops within a single farm, or across a farmed landscape, may improve the habitat suitability for butterflies and moths by increasing the availability of resources, or making that availability more consistent over time. For example, differences in flowering time or harvest time may increase the permability of the landscape for butterflies and moths, or mean that nectar resources are available for longer across the summer than if only a single crop type was present.

For studies on increasing diversity within a field, see “Plant more than one crop per field (intercropping)”.

Study locations

Key messages

Two studies evaluated the effects on butterflies and moths of increasing crop diversity across a farm or farmed landscape. Both studies were in Switzerland.

COMMUNITY RESPONSE (2 STUDIES)

Richness/diversity (2 studies): Two replicated, site comparison studies in Switzerland found that farms and landscapes with a greater number of habitats or crop types had a similar species richness of butterflies to farms and landscapes with fewer different habitats or crop types.

POPULATION RESPONSE (1 STUDY)

Abundance (1 study): One replicated, site comparison study in Switzerland found that farms with a greater number of habitats had a similar abundance of butterflies to farms with fewer different habitats.

BEHAVIOUR (0 STUDIES)

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A replicated, site comparison study in 2009–2011 in 133 mixed farms in the Central Plateau, Switzerland (Stoeckli et al. 2017) found that farms with a greater number of habitat types (including crop types) had a similar abundance and species richness of butterflies to farms with fewer habitat types. Both the abundance and species richness of butterflies on farms with more different habitats (>3/farm) were similar to farms with fewer habitats (<3/farm) (data presented as model results). A total of 133 farms (17–34 ha, 13–91% arable crops) were managed with “Ecological Compensation Areas” under agri-environment schemes. Management included extensive and low-input meadows with reduced fertilizer and later cutting dates, and the presence of trees, hedgerows and wildflower patches, as well as arable crops and pasture. From May–September 2009–2011, butterflies were surveyed six times on 10–38 transects/farm, totalling 2,500 m/farm. Each transect ran diagonally through a single crop or habitat type, with all available crops and habitats represented. All visits to a farm were completed in a single year, and the species richness was summed across all visits. Total abundance of butterflies was calculated from the number recorded in each habitat, and the availability of each habitat across the farm. Habitats on each farm were mapped between May and August.
Study and other actions tested
Referenced paper
Stoeckli S., Birrer S., Zellweger-Fischer J., Balmer O., Jenny M. & Pfiffner L. (2017) Quantifying the extent to which farmers can influence biodiversity on their farms. Agriculture, Ecosystems & Environment, 237, 224-233.
A replicated, site comparison study in 2010–2014 in 91 agricultural areas in the Swiss Plateau, Switzerland (Zingg et al. 2018) found that landscapes with a higher diversity of crops had a similar species richness of butterflies to landscapes with lower crop diversity. The species richness of butterflies was similar in agricultural areas with 7–12 different crops (11–33 species) and 1–6 crops (12–33 species). Ninety-one mixed farming areas (1 km²) were selected where 1–12 crop types were grown. Butterflies were surveyed seven times along a 2.5-km transect through each 1-km²area in one of five years (2010–2014).
Study and other actions tested
Referenced paper
Zingg S., Grenz J. & Humbert J. (2018) Landscape-scale effects of land use intensity on birds and butterflies. Agriculture, Ecosystems & Environment, 267, 119-128.

Please cite as:

Bladon A.J., Bladon, E. K., Smith R.K. & Sutherland W.J. (2023) Butterfly and Moth Conservation: Global Evidence for the Effects of Interventions for butterflies and moths. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

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This Action forms part of the Action Synopsis:

Butterfly and Moth Conservation

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