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2019 Update: Pollinators on Roadsides

The diversity and abundance of bees native to the tallgrass prairies of Minnesota are declining; one potential reason is changes in how land is used and managed. Native bees provide vital pollination services to our native prairie plants as well as agricultural crops. It is important to understand the factors involved in the decline of pollinators so they can be combatted and our plants be protected. In summer 2019, the focus of the Pollinators on Roadsides project was to collect bees using yellow pan traps and to take into account the burn history of the collection sites. We investigated the burn history of the collection sites to compare the bee collections from the last three years and determine if there is a relationship between burning and pollinator community composition. Thanks to local government records, inquiry with private land owners, and observation of recent burn evidence we discovered which of the 38 sites had a history of prescribed burning.

In summer 2019 Shea Issendorf and John Van Kampen collected a total of 422 bees from 38 yellow pan traps placed six times throughout the field season (June 28, July 11, July 18, July 31, August 8 and August 19). Trap locations include different land types such as agriculture, restored prairie and developed land. We determined the burn history of the trap locations in the last three years (2019, 2018 and 2017,) and whether the burns occurred in the spring, fall or both. We stored the bees in in vials of ethanol in freezers until they were pinned by Shea Issendorf and Mike Humphrey. We found that a lunchbox with ice packs could comfortably hold all the vials from a collection date for transportation from the field to the CBG.

The design and goal of this experiment is based on the original 2004 experiment by Wagenius and Lyon. They studied the relationship between characteristics of land and the abundance and diversity of pollinators. Using the data that came out of 2004, the reboot in 2017, and the continuation throughout 2018 and 2019, we observe how pollinator abundance and diversity has changed. With this valuable evidence of declining native pollinator communities, there is opportunity to change the way in which natural lands are used and how surrounding lands are treated (such as through burning, herbicide application and fragmentation).

Yellow pan traps resemble the yellow flowers of the Asteraceae family that native bees are attracted to.

 Start Year: 2004, rebooted 2017

Location: Roadsides/ditches around Solem Township. GPS coordinates for each trap are in a Google Map which Stuart Wagenius can share as needed.

Overlaps With: Ground nesting bees

Data/Materials Collected: 386 bee specimens collected; currently dried, pinned and stored at the Chicago Botanic Garden.  Specimens will be classified by Mike Humphrey before being sent to the University of Minnesota for further identification

Pinning records:

~Dropbox\teamEchinacea2019\sheaIssendorf\YPT 2019 Si\Si_YPTdatasheets2019.xlsx

 Land uses/7 traps that have burn history within last 3 years:

~Dropbox\teamEchinacea2019\sheaIssendorf\YPT 2019 Si\YPT trap land uses 1.xlsx

Other files associated with the project can be found in the folder

~Dropbox\ypt2004in2017\YPT2019

Team Members involved with this project: Shea Issendorf (2019,) Mike Humphrey (2018-2019,) John Van Kampen (2018-2019,) Kristen Manion (2017-2018,) Alex Hajek (2017,) and Steph Pimm Lyon (2004)

You can read more about pollinators on roadsides, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.

2018 Update: Pollinators on Roadsides

A bumblebee on a yellow flower. We use yellow pan traps to mimic these Asteraceae

Pollinator diversity and abundance are declining due in part to land use change such as habitat destruction and fragmentation, pesticide contamination, among other numerous anthropogenic disturbances. The extent to which pollinator and native bee diversity and abundance is changing is not well understood, especially within tallgrass prairie ecosystems. Pollinators are important in the prairie and they provide valuable ecosystem services to native plants and to economically important plants used in agriculture.

In summer 2018, we collected bee specimens from 37 roadside sites using yellow pan traps. These sites are located within a gradient of various surrounding landscapes, some surrounded by natural areas, semi-natural areas, agricultural fields, development, or a mixture of the above. IN summer ’17 we sampled over 600+ bee specimens across 8 sampling weeks. IN summer ’18, we captured similar abundances of bees (~450 specimens) collected across 6 weeks. Once specimens are collected, they are stored in ethanol until we are able to pin them. Once specimens are processed, we catalog specimens and keep a record for later specimen identification. Identifying specimens to species requires specific, expert knowledge of the families and genera of native bees and pollinators in this ecosystem.

The goal of this experiment was to repeat a similar study done in 2004 by Wagenius and Lyon, in which they collected information on pollinator abundance and diversity. The aim of the project was to understand how landscape characteristics may influence bee community composition. The information from this project allows us to make comparisons between the pollinator communities collected in 2017, and a similar project from 2004. This information can inform diversity and abundance changes across the 13-14 years and provide valuable insight into native bee declines in this system.

Year started: 2004, rebooted in 2017

Location: Roadsides in and around Solem Township, Minnesota.

Overlaps with: Ground nesting bees (link to come)

Samples collected: Over 450 bee specimens, currently being pinned at CBG

GPS points shot: Locations for each of the pan trap sites

Team Members who have worked on this project include:  Steph Pimm Lyon (2004), Alex Hajek (2017), Kristen Manion (2017 & 2018), and John VanKempen (2018). Also, a big thank you to Mike Humphrey who has worked in the lab pinning, processing, and cataloging native bee specimens from the 2017 and 2018 field seasons.

You can find out more about the pollinators on roadsides project and links to previous posts regarding it on the background page for this experiment.

2017 Update: Pollinators on roadsides

This summer we collected samples of pollinators from 39 roadside sites using yellow pan traps. We captured over 400 insects across 8 weeks. The specimens are stored frozen until pinning and identification. We will use this information to make comparisons between the pollinator communities collected in 2004. This information could inform potential diversity and abundance changes across the 13 years, and provide valuable insight into potential pollinator decline in this system.

Pollinator diversity and abundance are declining due in part to land use changes such as habitat destruction & fragmentation, pesticide contamination, and numerous other anthropogenic disturbances. The extent to which pollinator diversity and abundance is changing is not well understood, especially within tallgrass prairie ecosystems. Pollinators are important in the prairie: they provide valuable ecosystem services to native plants and to important plants used in agriculture.

The goal of this experiment was to repeat a similar study done in 2004 by Wagenius and Lyon, in which they collected information on pollinator abundance and diversity with the aim of relating landscape characteristics to bee community composition.

Augochlorella sp. foraging for pollen. Our yellow pan traps are similar in color.

GIS analysis of pollinator habitat

Read Ben’s Lee’s report and look at his map about pollinator habitat in Echinacea land.