Anna Persson. Foto.

Anna Persson

Forskare

Anna Persson. Foto.

When beggars are choosers—How nesting of a solitary bee is affected by temporal dynamics of pollen plants in the landscape

Författare

  • Anna S. Persson
  • Florence Mazier
  • Henrik G. Smith

Summary, in English

Wild bees are declining in intensively farmed regions worldwide, threatening pollination services to flowering crops and wild plants. To halt bee declines, it is essential that conservation actions are based on a mechanistic understanding of how bee species utilize landscapes. We aimed at teasing apart how foraging resources in the landscape through the nesting season affected nesting and reproduction of a solitary bee in a farmland region. We investigated how availability of floral resources and potentially resource-rich habitats surrounding nests affected nest provisioning and reproduction in the solitary polylectic bee Osmia bicornis. The study was performed in 18 landscape sectors dominated by agriculture, but varying in agricultural intensity in terms of proportion of organic crop fields and seminatural permanent pastures. Pasture-rich sectors contained more oak (Quercus robur), which pollen analysis showed to be favored forage in early season. More oaks ≤100 m from nests led to higher proportions of oak pollen in nest provisions and increased speed of nest construction in early season, but this effect tapered off as flowering decreased. Late-season pollen foraging was dominated by buttercup (Ranunculus spp.), common in various noncrop habitats. Foraging trips were longer with more oaks and increased further through the season. The opposite was found for buttercup. Oak and buttercup interacted to explain the number of offspring; buttercup had a positive effect only when the number of oaks was above the mean for the studied sectors. The results show that quality of complex and pasture-rich landscapes for O. bicornis depends on preserving existing and generating new oak trees. Lignose plants are key early-season forage resources in agricultural landscapes. Increasing habitat heterogeneity with trees and shrubs and promoting suitable late-flowering forbs can benefit O. bicornis and other wild bees active in spring and early summer, something which existing agri-environment schemes seldom target.

Avdelning/ar

  • Centrum för miljö- och klimatvetenskap (CEC)
  • Biologiska institutionen
  • BECC - Biodiversity and Ecosystem services in a Changing Climate

Publiceringsår

2018-06-01

Språk

Engelska

Sidor

5777-5791

Publikation/Tidskrift/Serie

Ecology and Evolution

Volym

8

Issue

11

Dokumenttyp

Artikel i tidskrift

Förlag

Wiley-Blackwell

Ämne

  • Ecology

Nyckelord

  • agri-environment schemes
  • central-place forager
  • farmland biodiversity
  • organic farming
  • pollen foraging
  • pollinator
  • red mason bee

Status

Published

Projekt

  • Scale-dependence of mitigation of pollinator loss

ISBN/ISSN/Övrigt

  • ISSN: 2045-7758