Buffer zone width: influence on biodiversity of butterflies and pollinating insects
Item is


Nimgaard, Rasmus1, Forfatter
Navntoft, Søren1, Vejleder
Esbjerg, Peter1, Vejleder
1Det Biovidenskabelige Fakultet, København, Danmark
skjul Ophav
Vis Ophav


Ukontrollerede emneord: -
 Abstract: This thesis presents a one-season field investigation of the influence of buffer zone width on the biodiversity of butterflies and pollinating insects. The buffer zones, bordering hedgerows, were placed in spring barley fields, but did not receive fertilizers or pesticides. The Danish Ministry of Environment, in a response to a review on buffer zones in arable fields (Sigsgaard et al. 2007), made a call for research. The present project started in 2008 and incorporates buffer zones of 4, 6, 12 and 24 m width and a 0 m control.The aim of the project was to investigate the influence of the 4 different buffer zones on the biodiversity of butterflies and pollinating insects. If possible the project should also try to identify a buffer zone width, which would provide a significant increase in abundance and biodiversity. The buffer zones were placed along hedgerows in four large fields at Gjorslev Estate on Eastern Zealand. In May, June and July butterflies and pollinating insects such as honey bees, bumblebees andhoverflies were recorded by transect counts along with sweep net sampling of the field and hedge bottom areas. In addition systematic photographic recordings of flowers providing nectar and pollen resources as well as butterfly larval host plants were performed.Butterflies and pollinating insects were identified to species except for solitary bees and hoverflies and analysed in relation to; buffer zone width, distance to hedgerow, abundance of flowers and butterfly larval host plant cover.The abundance of hoverflies, when considering all stages (adult, pupa and larva), increased significantly with a buffer zone width of 12 m in June and 6 m in July, whereas the activity of adult hoverflies was not affected by buffer zone width. The activity of bumblebees and butterflies in July was positively correlated and increased significantly with abundance of thistle flowers in the hedge bottom, and in general with the number of flowers in the field. Further there was found a positive relation between the activity of abutterfly genus (Pieris) and larval host plant cover. Bumblebees were low in numbers, and effect of buffer width on neither their activity nor their diversity was found. For butterflies a buffer width of 12 m increased the activity significantly in July, and the diversity was increased with just a 6 m wide buffer zone. Therefore, a buffer width between 6 and 12 m seems to be the best compromise when considering the trade-off between biodiversity gains and costs of buffer zones, and they should be worth considering as a general measure to counteract the decreasing biodiversity in the arable landscape, which constitutes 62 % of Denmark’s area.The butterflies proved to have potential as indicators of other increases in biodiversity found in a larger adjacent project.
skjul Indhold
Vis Indhold


Buffer_zone_width_FINAL_all.pdf (Hovedtekst)
Mime-type / størrelse:
application/pdf / 7MB
Copyright dato:
Copyright information:
De fulde rettigheder til dette materiale tilhører forfatteren.
skjul Filer
Vis Filer


Bogmærk denne post:
 Type: Speciale
skjul Basal
Vis Basal


Vis Links


Sprog: English - eng
 Datoer: 2009
 Sider: 90 pages
 Publiceringsinfo: København, Danmark : Institut for Jordbrug og Økologi
 Indholdsfortegnelse: -
 Note: Agricultural Science, Agronom
 Type: Speciale
skjul Detaljer
Vis Detaljer


Vis Kilde