Leave unharvested crop headlands within arable fields

Overall effectiveness category Awaiting assessment
Number of studies: 1
Share Tweet Email

View assessment score

How is the evidence assessed?

Effectiveness

not assessed
Certainty

not assessed
Harms

not assessed

Calculating overall effectiveness category

Background information and definitions

Harvesting crops creates a dramatic change in the farmed landscape, by suddenly and simultaneously removing plants, which may be providing nectar resources to butterflies and moths, from a large area. Even if butterflies and moths are not using the crop itself, harvesting disturbs the structure of the field, and may cause mortality of caterpillars living on other plant species within or around the crop. Leaving unharvested strips, known as headlands, at the edge of fields may provide both shelter and a continued resource availability to butterflies and moths.

Study locations

Key messages

One study evaluated the effects of leaving unharvested crop headlands within arable fields. This study was in France.

COMMUNITY RESPONSE (1 STUDY)

Richness/diversity (1 study): One replicated, paired, site comparison study in France found that unharvested alfalfa headlands had a greater species richness of butterflies than harvested alfalfa or wheat fields.

POPULATION RESPONSE (1 STUDY)

Abundance (1 study): One replicated, paired, site comparison study in France found that unharvested alfalfa headlands had a higher abundance of butterflies than harvested alfalfa or wheat fields.

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, paired, site comparison study in 2009–2010 on 24 farms in Champagne-Ardennes and Haute-Normandie, France (Manil & Chagué 2014) found that unharvested alfalfa Medicago sativa headlands had a higher abundance and species richness of butterflies than harvested alfalfa or wheat Triticum spp. fields. In unharvested strips of alfalfa, the abundance (53 individuals/transect) and species richness (4 species/transect) of butterflies was higher than in harvested alfalfa (abundance: 12–15 individuals/transect; richness: 2–3 species/transect) or in conventional wheat fields (abundance: 3–6 individuals/transect; richness: 1–2 species/transect). See paper for individual species results. On each of 24 farms, one alfalfa field was harvested conventionally 4–5 times/year, one alfalfa field had a rotational 7-m strip left unmown during each harvest, and one winter wheat field was managed conventionally. From May–September 2009–2010, butterflies were surveyed visually five times/year on two 200–400-m transects in each field (15–17 farms surveyed/year).
Study and other actions tested
Referenced paper
Manil L. & Chague J. (2014) Differentiated management of alfalfa fields: a positive impact on butterfly populations (Lepidotera: Rhopalocera). Revue d'Écologie (La Terre et La Vie), 69, 101-111.

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

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Butterfly and Moth Conservation

Related Actions

Actions	Effectiveness	Studies	Category
Plant nectar flower mixture/wildflower strips Action Link	Evidence not assessed	23	Synopsis Link
Leave uncropped, cultivated margins or plots Action Link	Evidence not assessed	4	Synopsis Link
Undersow spring cereals, with clover for example Action Link	Awaiting assessment	2	Synopsis Link