I presented artwork studies to own bumble bees at each and every of seven sites within the same around three census periods as we counted floral money diversity (twenty eight May so you’re able to 7 Summer, 22-29 Summer, 22-29 July). Per of about hyvГ¤ sivusto lГ¶ytää rotujenvГ¤linen treffit three bumble bee surveys, i went along to each site three times, after during the all of three time periods (0800-1100, 1100-1300, 1300-1700 days). Most of the sampling was accomplished into the bright days with temperature ranging from 19 and thirty-two°C.
I trapped and you can marked each bumble-bee having a tiny mark out-of colored modification water for the thorax to get rid of counting somebody more often than once throughout a sampling period from the a web page. I registered bumble-bee species, status, and the plant kinds about what new bumble-bee are discover foraging and you can put out the brand new bee. I spent 31 minute for every single check out from the a few websites with a segmet of ?dos,000 yards 2 , forty-five minute at two 10,000-m dos internet, ninety min on two 31,000-yards 2 websites, and you may 120 minute in the two 70,000-m dos sites. We checked-out to own a sampling go out bias playing with rarefaction (find Statistical Data)parisons regarding abundance out of bees stuck by the hour to money viewpoints otherwise habitat sizes got rid of possible testing time biases.
I understood bumble bees in the world using Mitchell (1962) while the an initial expert; to own descriptions out of regional species, i put Medler and Carney (1963). Hendrix at College regarding Iowa. The fresh bush kinds was indeed later on categorized as indigenous or put so you’re able to become familiar with perhaps the bumble bees, which are indigenous, demonstrated needs getting native blooming variety.
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 Plants included on the list were those from which we captured bumble bees in this and related studies (C. Gienapp, unpublished data).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 potential predictors out of bumble-bee diversity and you can abundance per hours using initial easy regression analyses researching all of them contrary to the percentage and you will LRI of each and every individual and you can combined surroundings varying ( Table 2) from the both five-hundred- and you can 700-m radii and webpages parameters (variety, assortment, and you may density out of bumble-bee-went along to blooming ramets). Landscaping predictors appearing benefits, hence picked for further analyses was basically LRI of the landscape on five-hundred and you will 700 meters (with and without the webpages) therefore the percentage of shared grasslands in the surroundings ( Table 2). I decided to explore LRI viewpoints having and you will with no website included to look at the fresh cousin benefits from flowery sources of the newest landscaping and web site in itself to diversity and you will abundance and the end result of the land and you can site mutual. Extreme webpages predictors was basically Simpson diversity, wealth, and you may occurrence regarding flowering ramets out of bush varieties went to from the bumble bees.
Voucher specimens off bumble bees are located in the latest line of Stephen D
We made use of Pearson product-second relationship analyses to examine for collinearity ranging from prospective predictors out of bumble-bee range and wealth hourly just before multiple regression analysis. Range, wealth, and you may occurrence out of flowering ramets at the webpages just weren’t coordinated with the LRI of the land (with and you will without any web site included) at the five hundred- otherwise 700-meters radii (the roentgen 0.16). But not, there was weakened collinearity between your website attributes off occurrence and you may variety out of flowering ramets of species employed by bumble bees (r = 0.668, P = 0.07), and simply one among them two regional procedures from information is utilized in a regression model. In every designs, i just use predicators demonstrating no collinearity (P > 0.10).