In the summers of 2017-2019, we’re sampling Portland area gardens for pollinators.  You can learn more about our work, here.

  • Garden Selection:  Our goal was to sample 20-30 Portland area home and community gardens over three years.  We advertised our project at the Fall 2016 Metro Master Gardener re-certification, which was attended by ~250 Master Gardener volunteers.  At that event, 123 folks registered their interest in participating.  After circulating a follow-up survey, with more details about the study, 56 folks noted that they remained interested in participating in the study.  From these 56 potential study sites, I chose three transects with 31 potential study sites:
    • the Urban Core:  gardens located within Portland, in highly populated neighborhoods
    • the Forest Edge: gardens located within Portland, located adjacent to Forest Park
    • the Portland Suburbs:  gardens located outside of Portland, in a peri-urban landscape

We contacted these 31 potential study sites, and heard back from 25 people.  In April, visited each of these 25 potential study sites, to ensure that they are suitable sites for this study.  We ultimately settled on 24 study sites for our 2017 sample. In 2018, we scaled back to 22 sites, to make the study a bit easier to manage.

  • Bee Sampling Methods:  we will be using a modification of the standardized method for monitoring bee populations, developed by LeBuhn, Griswold, McKinley, Droege, Roulston, Cane, Parker, Buchmann, Tepedino, Williams, Kremen and Messenger.  Specifically, we will use colored bowl traps to passively sample bees from home gardens.  Following Fetridge et al. (2008), we will focus our collections in flowerbeds, rather than lawns.  We’ll place six water pan traps into each garden (two blue, two yellow and two white).  We will also hand collect bees, allocating 10 minutes of collection time within each garden.
  • Preliminary Results:
  • Bees (more will be added, as they are identified to species)
    • Apis mellifera
    • Anthidium manicatum
    • Bombus flavifrons
    • Bombus californicus
    • Bombus mixtus
    • Bombus rufocinctus
    • Bombus sitkensis
    • Melissodes sp.
    • Agopostemon virescens
    • Agopostemon angelicus/texanus
    • Agopostemon texanus
    • Lasioglossum pacificum
    • Lasioglossum sisymbrii
    • Lasioglossum zonulum
    • Lasioglossum titusi
    • Megachile rotundata
    • Megachile angelarum
    • Ceratina (subgenus Zadontomerus)
    • Halictus ligatus
    • Halictus tripartitus
  • Butterflies
    • Cabbage white
    • Woodland Skipper
    • Grey Hairstreak
    • Western Tiger Swallowtail
    • California Tortoiseshell