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We used artwork surveys to have bumble bees at each and every of eight web sites in the same around three census periods once we measured flowery resource variety (twenty eight Will get so you’re able to seven June, 22-30 Summer, 22-31 July). For every minun selitykseni of the around three bumble-bee studies, i went along to for each and every web site three times, after while in the every one of three-time attacks (0800-1100, 1100-1300, 1300-1700 days). The testing is carried out to the bright months that have heat between 19 and you will thirty-two°C.

I caught and you can noted per bumble bee which have a little dot regarding coloured modification water towards thorax to eliminate depending individuals more than once throughout the a sample period from the a site. We recorded bumble-bee kinds, status, as well as the bush variety on which brand new bumble-bee is located foraging and put out the new bee. We spent 31 min for every single go to in the two internet sites with a segmet of ?2,000 m dos , forty-five minute on several 10,000-yards dos web sites, 90 min in the several 31,000-yards 2 websites, and 120 min during the a couple 70,000-meters dos internet. I checked-out getting a sample day prejudice playing with rarefaction (come across Mathematical Investigation)parisons from wealth out of bees stuck by the hour to investment beliefs or environment sizes got rid of prospective testing go out biases.

I known bumble bees in the field having fun with Mitchell (1962) as the an initial power; for descriptions off local kinds, i put Medler and you will Carney (1963). Hendrix in the University off Iowa. This new plant types was basically later on categorized because the native or put to become familiar with whether or not the bumble bees, that are native, shown choice getting indigenous flowering types.

Mathematical 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 Plants included on the list were those from which we captured bumble bees in this and related studies (C. Gienapp, unpublished data).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 known potential predictors of bumble bee range and you can abundance each time using initial easy regression analyses evaluating all of them up against the payment and you may LRI of each and every private and you may joint land varying ( Table 2) at both five-hundred- and you may 700-m radii and site parameters (wealth, diversity, and you will occurrence out-of bumble bee-decided to go to flowering ramets). Landscape predictors demonstrating significance, which picked for additional analyses was LRI of land at the 500 and you may 700 meters (that have and you will without the web site) as well as the portion of shared grasslands from the landscaping ( Table 2). I decided to play with LRI opinions which have and you can without the webpages integrated to look at brand new cousin efforts off flowery resources of the latest land and you may web site by itself to assortment and you can variety also the end result of your own landscaping and you may web site combined. Significant web site predictors was Simpson assortment, wealth, and you may occurrence off blooming ramets regarding plant species went to by the bumble bees.

Coupon specimens regarding bumble bees come in the newest collection of Stephen D

I put Pearson unit-second relationship analyses to examine getting collinearity ranging from possible predictors out-of bumble-bee range and you will wealth per hour in advance of numerous regression study. Assortment, abundance, and density regarding blooming ramets at website just weren’t correlated on LRI of your own landscaping (which have and you can without the webpages integrated) during the five-hundred- otherwise 700-yards radii (most of the roentgen 0.16). Although not, there can be poor collinearity between the web site attributes out of density and you will wealth off flowering ramets out-of species employed by bumble bees (roentgen = 0.668, P = 0.07), and simply one of them two local measures regarding tips are utilized in virtually any regression design. In most models, i just use predicators exhibiting zero collinearity (P > 0.10).