I used visual surveys to own bumble bees at each and every of your 7 websites for the exact same about three census symptoms as we measured flowery investment range (twenty-eight Could possibly get so you’re able to 7 June, 22-31 Summer, 22-31 July). For each and every of your about three bumble bee surveys, we went to per website 3 times, after throughout the each one of three-time periods (0800-1100, 1100-1300, 1300-1700 occasions). Most of the sampling try carried out towards sunny weeks which have temperatures between 19 and you can thirty-two°C.
I caught and you can noted for each and every bumble-bee that have a small mark out-of coloured correction liquid towards the thorax to end counting individuals more than once during a sampling several months at web site. We submitted bumble bee types, caste, together with plant variety about what the latest bumble bee is found foraging and you will put out the bee. I spent 30 minute for every single head to in the several web sites which have an area of ?2,000 m dos , forty five min within a couple of ten,000-m dos sites, ninety min on a couple 29,000-yards 2 internet, and you will 120 minute during the two 70,000-yards 2 web sites. I checked out to have a sampling date bias playing with rarefaction (look for Analytical Study)parisons of wealth regarding bees stuck hourly so you can capital thinking otherwise environment systems got rid of prospective sampling go out biases.
I identified bumble bees in the world having fun with Mitchell (1962) while the a first expert; to own descriptions regarding regional species, i utilized Medler and you can Carney (1963). Hendrix within College out of Iowa. New bush varieties had been afterwards categorized because indigenous otherwise brought so you’re able to get acquainted with if the bumble bees, which are local, presented preferences to possess indigenous blooming kinds.
Statistical Analyses.
We used the log2 Shannon-Wiener index to calculate bumble bee species diversity using cumulative abundances across all censuses. We also used cumulative abundances of ramets of plant species visited by bumble bees to obtain seasonal totals of available floral resources for each site. Plants included on the list were those from which we captured bumble bees in this and related studies (C. Gienapp, unpublished data). Only rarely did a plant species appear in more than one census, and therefore it is unlikely that the same ramets were counted twice in seasonal abundance measures. We examined plant diversity using the Simpson index rather than the Shannon-Wiener index because the former is less sensitive to rare plant species. These rare species are unlikely to have a strong effect on bumble bee diversity and abundance.
I identified prospective predictors of bumble bee assortment and you will abundance for every single time using original easy regression analyses evaluating them against the payment and you will LRI of every individual and you will shared land changeable ( Desk dos) at one another five hundred- and 700-yards radii and web site variables (abundance, range, and you can density of bumble bee-visited flowering ramets). Landscaping predictors indicating advantages, and therefore picked for further analyses was in fact LRI of landscaping at five hundred and you will 700 yards (with and with no site) and the part of mutual grasslands throughout the land ( Table 2). I chose to play with LRI thinking having and without having any website integrated to examine brand new relative benefits off flowery types of new landscape and you will site itself so you can range and you will variety including the result of the landscape and you may site shared. Tall webpages predictors was basically Simpson range, abundance, and you will density off flowering ramets of bush types decided to go to of the bumble bees.
Voucher specimens of bumble bees are in the brand new line of Stephen D
We made use of Pearson device-moment correlation analyses to look at having collinearity ranging from potential predictors regarding bumble bee range and you will abundance each hour before numerous regression data. Diversity, abundance, and you will density off blooming ramets in the webpages weren’t synchronised toward LRI of your landscaping (which have and with no website integrated) during the five-hundred- otherwise 700-yards radii (all of the roentgen 0.16). not, there clearly was poor collinearity between the webpages features away from thickness and wealth out-of blooming ramets off varieties employed by bumble bees (roentgen = 0.668, P = 0.07), and simply one of them a few regional measures out of information was found in any given regression design. Kazakstan-naiset In every activities, we only use predicators appearing zero collinearity (P > 0.10).