Promoting Native Bumblebees in Agricultural systems for conservation and ecosystem service

Project Overview

GW09-018
Project Type: Graduate Student
Funds awarded in 2009: $20,074.00
Projected End Date: 12/31/2009
Grant Recipient: University of California, Berkeley
Region: Western
State: California
Major Professor:
Dr. Claire Kremen
University of California, Berkeley

Annual Reports

Commodities

  • Animals: bees

Practices

  • Education and Training: on-farm/ranch research, workshop
  • Farm Business Management: whole farm planning
  • Natural Resources/Environment: biodiversity, hedgerows

    Abstract:

    Invasive plant species have been observed altering plant-pollinator webs and devastating plant communities by out-competing native plant species. Despite these observations, little is known about the direct effects invasive plants have on native bees, or if these effects are positive, negative or neutral.

    This project focuses on understanding the direct effects of invasive plants on a native bee species. By identifying use, preference and nutrition of native and invasive plants, I hoped to better understand how the encroachment of invasive plants are influencing native bee pollen resource use and nutrition.

    This information will be used to improve hedgerows in agricultural areas and to inform land-managers of the most important floral resources for conservation of native bees.

    Introduction

    Global pollinator declines threaten the sexual reproduction of an estimated 90% of flowering plant species and 70% of crop species (Klein et al. 2007; Kearns et al. 1998; Potts et al. 2010; Ashman 2004). In species that require or benefit from animal-mediated pollination, these declines can result in pollen limitation and seed limitation that have demographic consequences on plant reproduction (Knight et al. 2005; Young et al. 2005; Aguilar et al. 2006) and threaten food security, ecosystem stability and the provision of valuable ecosystem services (Allen-Wardell et al. 1998; Potts et al. 2010). The rapid decline of European honeybee (Apis mellifera) colonies, the primary agricultural pollinators, from Colony Collapse Disorder threatens to drastically impact food production and has intensified the need to seek alternate pollinators, such as native bees (Winfree et al. 2007). However, native pollinators are also declining (Biesmeijer et al. 2006), placing even greater need on understanding and conserving this crucial ecosystem service.

    Although conserving pollinators has become a major area of research, especially in agricultural areas, one major limitation is a lack of specific information on pollinator needs and preferences. Using Bombus vosnesenskii as a model species, we determined plant preferences in natural environments and identified characteristics of plants that influence preference.

    Project objectives:

    1) Quantify the available pollen resources in grassland sites.

    2) Identify pollen sources chosen by bumble bees.

    3) Evaluate the characteristics of the plants chosen by bumble bees.

    4) Identify the native plants that are essential to bumble bees throughout their life cycle.

    5) Quantify changes in bumble bee abundance after improving hedgerows.

    6) Provide information to farmers, researchers and societies to improve conservation, pollination and restoration efforts, especially oriented toward these important agricultural pollinators, bumble bees.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.