Natural and within-farmland biodiversity enhances crop productivity

L. G. Carvalheiro^1,2*, R. Veldtman^1,3, A. G. Shenkute², G. B. Tesfay², C. W. W. Pirk², J. S. Donaldson^1,4 and S. W. Nicolson²

Abstract
Ongoing expansion of large-scale agriculture critically threatens natural habitats and the pollination services they offer. Creating patches with high plant diversity within farmland is commonly suggested as a measure to benefit pollinators. However, farmers rarely adopt such practice, instead removing naturally occurring plants (weeds).

By combining pollinator exclusion experiments with analysis of honeybee behaviour and flower-visitation webs, we found that the presence of weeds allowed pollinators to persist within sunflower fields, maximizing the benefits of the remaining patches of natural habitat to productivity of this large-scale crop. Weed diversity increased flower visitor diversity, hence ameliorating the measured negative effects of isolation from natural habitat. Although honeybees were the most abundant visitors, diversity of flower visitors enhanced honeybee movement, being the main factor influencing productivity.

Conservation of natural patches combined with promoting flowering plants within crops can maximize productivity and, therefore, reduce the need for cropland expansion, contributing towards sustainable agriculture.


Source
Ecology Letters (2011) 14: 251-259
DOI: 10.1111/j.1461-0248.2010.01579.x


Author Locations and Affiliations
(1) Applied Biodiversity Research, South African National Biodiversity Institute, Kirstenbosch Research Centre, Private Bag X7, Claremont 7735, South Africa
(2) Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa
(3) Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
(4) Botany Department, University of Cape Town, Rondebosch, Cape Town, South Africa
* Corresponding author, E-mail  l.g.carvalheiro@leeds.ac.uk


Posted March 2011