Acknowledgments

1
The effects of knapweed on pollinator decline
Curtis Monteau Jr., University of Montana,
Project TRAIN Undergraduate Research Fellowship
Abstract In the summer of 2005, we conducted
pollinator research on the Bandy Ranch located 55
miles east of Missoula, Mt. on hwy 200. Two sites
with similar elevations had 75m x 75m modified
Whittaker plots laid out, and vegetation
assessments were conducted on both sites, weather
data were collected and bee pollinators were
netted. These were then typed into cover
classes, and the data was analyzed. The percent
of forbes were the same for each site. But, each
site contained different species. Site 1 was the
control site, and was overrun with knapweed.
Knapweed is classified as a forb, and this is why
the forb values were so similar. No differences
were shown in the weather data from each site,
for the entire research project. The bees that
were collected from each site showed that a
greater percentage of the Halictidae, and
Megachilidae families preferred the knapweed
control site. More research should be done to
find out why this is.

• Results
• The percent cover of the forbes values on the
  pie graphs in figures 1, and 2. were the same
  but, the species were different. Knapweed is a
  forb, and is highly represented in site 1. Which
  was our control site for, the research project.
• The weather data showed no significant
  differences for the research project.
• The percentage of bee families (figure 4,5)
  did show some differences in each site.
• Halictidae, and Megachilidae preferred site 1
  the control site with heavy knapweed.
• These results show that some families have a
  preference for knapweed.
• Too small a sample size, number of bees caught,
  may have been a factor in our research.
• The spraying of vegetation by managers at Bandy
  Ranch may have contributed to the small sample
  size.
• The time of year may also have been a factor.

Introduction Knapweed is an invasive weed that
is prevalent in North America and has become a
problem in the United States, especially in
Montana. There are two types of knapweed in
Montana, spotted knapweed (Centaurea maculosa),
and diffuse knapweed (Centaurea diffusa). Both
knapweed types originated in Europe where it
favors dry soils, and disturbed areas (Anez, B.
2005). Knap weed costs the state of Montana 42
million dollars per year to control. The invasive
weed has overrun more than 8.2 million acres in
Montana alone. This noxious weed takes over
pasture land, wildlife forage, native plants, and
effects water quality for fish habitats. Knapweed
is spread by wind dispersal, vehicle tires, pets,
horses, and the shoes of outdoor adventurers.
Bees are pollinators of fruits, vegetables, and
wildflowers for human and wildlife consumption.
There has also been a decline in the native bee
populations world wide (Corbet, 1997). The
purpose of our research project was to see if
knapweed has an effect on pollinator communities
in Western Montana.

• Methods
• A 75m x 75m modified Whittaker plot was measured
  out, and divided into nine 25m x 25m quadrates on
  two sites. The two sites were located on the
  Bandy Ranch located 55 miles east of Missoula Mt.
  on hwy 200. The elevations of the two sites were
  similar, site1 was 3,176 feet, and site2 was
  3,104 feet. The plots were measured out with a
  50m tape. A vegetation assessment was then
  conducted on each site, and then typed into a
  cover class( see fig.1, fig.2).
• Bees were collected using two methods, yellow
  pan method, and the aerial net method. The yellow
  pan method is done by filling pie pans a quarter
  to half ways full with a soap and water mixture.
  This mixture helps break the surface tension of
  the water, and helps drown the bees as they fly
  into the pans of soapy water mixture.
• A total of nine pans were laid out one for each
  quadrate by 1000am, and were picked up by 200pm
  each day of collection.
• The aerial net method was conducted twice a day.
  The aerial netting was preformed by walking
  through each quadrate, and moving the net through
  the vegetation in a sweeping motion. Any bees
  that were captured with nets or in the pans were
  collected, and labeled with the appropriate site
  information. The bees were then taken back to the
  lab and classified into the appropriate families,
  and genera.
• Materials
• etrex Legend GPS unit
• Kestrel 3000 pocket weather meter
• aerial nets
• yellow pie pans
• 50m tape
• 1m x1m pvc quadrate
• marker flags
• water proof note book
• aspirators
• storing jars
• pro mark agricultural foam marker

Discussion and Conclusions Bees are important
to the stability of the yield of food crops all
over the world, and are showing a significant
decline (Meffe, 1997). There may have been great
losses in the pollinator communities already,
that may lead to extinctions of some bee species
( Corbet, 1997). Devastations may also occur to
fruits, and flowers that are greatly counted on
by wildlife and humans alike. I think the Bandy
Ranch is a great place to do research, and
further investigations should be done here to see
if there is a decline in pollinators. One of the
main reasons for the inconclusive results for bee
communities was our sample size. We think a
greater sample size is need to show significant
results for this type of research project. A
longer collection period for pollinators would
also show greater results.
Literature Cited Cook, B.J. 2001. Temporary
connections make isolated wetlands function at
the landscape scale. Ph.D. dissertation. Division
of Biological Science, The University of Montana.
Missoula, MT. 70 pp. Meffe, G.K. 1998. The
potential consequences of pollinator declines on
the conservation of biodiversity and stability of
food crop yields. Department of Sustainable
Development and Conservation Biology, The
University of Maryland. Volume 12, No. 1 p
8-15. Corbet, S.A. 1997. Role of pollinators in
species preservation, conservation, ecosystem
stability and genetic diversity. Department of
Zoology, Cambridge University, United Kingdom. p
219-228.
Figure 1.
Figure 2.
Acknowledgments I would like to thank Penny
Kukuk and Anne Greene of the TRAIN Program, Larry
LaCount, Heather Cahoon of the McNair Scholars
Program, all the staff of the TRAIN Program, my
wife Sherry, and most of all My friend John Hill
for all his help and mentoring, thank you all.
Figure 3.
Figure 4.