Roadside Revegetation

MONITORING PROCEDURES
Alternatively, Idaho fescue did show an increase in mean crown cover from 2001 (cell C10) to
2006 (cell C5). This increase was found to be significantly significant because both the upper
and lower confidence limits were positive. The team could be 90 percent confident that there
was a true increase in crown cover.
12.10 POLLINATOR MONITORING PROCEDURES
This standardized monitoring procedure provides instructions for monitoring native bees,
honey bees, and monarch butterflies to assess the quality of revegetated roadsides as
pollinator habitat. The data collected from these procedures will allow the project designer
to determine if the revegetation project successfully addressed pollinator-specific DFCs. The
procedure can be used to assess roadside vegetation in three ways: (1) to indicate whether
revegetation efforts have increased pollinator diversity and abundance (by including nearby
non-revegetated roadsides in samples as reference sites), (2) to determine if pollinator diversity
and abundance change over time, and (3) to compare the effects of different management
strategies or seed mixes on pollinators. This straightforward pollinator sampling procedure
can be conducted with minimal training and time, yet provides a quantitative measure of bee
diversity. This procedure only requires that the user be able to differentiate native bees from
other insects visiting flowers and recognize honey bees and monarch butterflies during two
half-hour visits per location per year.
It is important to note that counting individuals of European honey bees alone cannot provide
a measure for the value of habitat for native bees or other pollinators because the number
of individual honey bees visiting habitat is primarily determined by the number of managed
hives in the vicinity. Although the presence of honey bees does indicate that the vegetation
supports bees, it does not demonstrate how well the vegetation increases abundance and
diversity of other species of bees or pollinators.
To evaluate a particular site, two separate visits need to be made per growing season to conduct
a timed assessment to observe and count bees on flowers along two transects. Samples should
be made in the middle of the growing season. In California, for example, May through July
is the ideal sampling window, while in the Upper Midwest or Northeast July through August
is preferred. Samples should also be made only when weather conditions are warm, sunny,
and calm, with air temperatures over 60° F, wind speeds less than 10 miles per hour, and skies
mostly clear. Pollinators are most active between 8 a.m. and 4 p.m.
Two linear transects of 100 feet each should be established per site, ideally in full sun because
bee activity declines in shade. To begin sampling, walk the transect for 7.5 minutes and
count bees on flowers within a 3-foot-wide strip of the transect. Walk so that your shadow is
behind you rather than in front, and watch all the open flowers within 3 feet to one side of
the transect. Record each bee that lands on the reproductive structures of the flower for more
than 0.5 second. Use a timer and pause it as needed to record an insect before restarting it
when ready to resume observations. Set a careful pace so that the whole 100-foot transect is
covered within 7.5 minutes. While moving through the transect, keep a tally of the number
of native bees, honey bees, and monarch butterflies observed. The same bee or butterfly
should not be counted twice even if it visits multiple flowers because the overall goal is to
count the number of individuals using the site rather than the rate of floral visitation. Records
of samples should also include the site name, date, name of the sampler, weather conditions,
time of visit to the site, and any pertinent notes about the site and the vegetation present,
such as which flowers in bloom seem to be attracting the most pollinators. An example of a
data sheet is included in the appendix.
The number of native bees counted through this survey procedure correlates positively with
the overall diversity of native bees at a site; therefore, if a large abundance of individuals is
present, that indicates higher diversity. If multiple roadside sites are surveyed, the differences
observed in native bee abundance will reflect differences in habitat quality among sites. Native
Roadside Revegetation: An Integrated Approach to Establishing Native Plants and Pollinator Habitat
412