We conducted graphic surveys to own bumble bees at every of the seven web sites inside the exact same three census symptoms even as we mentioned flowery investment diversity (twenty eight May to help you eight Summer, 22-29 June, 22-30 July). Each of your about three bumble-bee studies, i decided to go to for each and every site 3 x, immediately following throughout all of three-time attacks (0800-1100, 1100-1300, 1300-1700 instances). All of the sampling is carried out on bright weeks that have temperatures anywhere between 19 and you will thirty two°C.
I stuck and you will noted each bumble bee having a little dot out of coloured modification water to your thorax to end relying some one more often than once throughout a sampling period in the a web site. I submitted bumble bee varieties, status, and the bush variety about what the bumble-bee is found foraging and you may put out new bee. We spent 31 min for each head to from the several web sites having a segmet of ?dos,000 yards 2 , 45 minute at the a couple of 10,000-m 2 websites, 90 min on a couple 29,000-yards dos sites, and you may 120 min at several 70,000-yards dos internet. We examined to possess a sampling go out bias using rarefaction (find Analytical Data)parisons out of variety out of bees stuck each hour in order to resource beliefs otherwise environment versions removed potential sampling day biases.
We recognized bumble bees on earth having fun with Mitchell (1962) as a first power; having meanings out of regional types, i used Medler and you may Carney (1963). Hendrix during the College or university from Iowa. The brand new bush species were later classified due to the fact indigenous otherwise brought to help you familiarize yourself with whether or not the bumble bees, which are native, presented choice for local blooming species.
Analytical 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 Plants included on the list were those from which we captured bumble bees in this and related studies (C. Gienapp, unpublished data).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 possible predictors out-of bumble bee variety and you will variety for each hr playing with preliminary effortless regression analyses contrasting them contrary to the fee and you can LRI of every beautiful Jodhpur women private and you will combined landscape variable ( Desk 2) from the one another 500- and you will 700-yards radii and web site variables (abundance, assortment, and you may density regarding bumble bee-went along to flowering ramets). Landscape predictors appearing significance, and therefore chosen for further analyses was LRI of one’s land from the 500 and you will 700 m (having and you can with no website) and percentage of combined grasslands regarding the surroundings ( Table dos). We chose to explore LRI philosophy having and you can with no website included to look at the fresh new relative benefits off floral sources of the newest landscaping and you will website by itself so you can assortment and you will variety in addition to the effect of one’s surroundings and web site combined. Extreme site predictors had been Simpson diversity, wealth, and thickness regarding flowering ramets regarding bush variety visited by the bumble bees.
Voucher specimens out-of bumble bees are in new distinct Stephen D
I used Pearson unit-time relationship analyses to look at to possess collinearity ranging from possible predictors of bumble bee diversity and you will abundance by the hour prior to several regression analysis. Variety, wealth, and you will occurrence off flowering ramets during the webpages weren’t correlated toward LRI of surroundings (that have and with no site incorporated) in the five hundred- or 700-m radii (all the r 0.16). But not, there is certainly weakened collinearity amongst the webpages characteristics away from occurrence and abundance out-of blooming ramets out of varieties utilized by bumble bees (roentgen = 0.668, P = 0.07), and just one among these a few local measures of resources was utilized in virtually any regression model. In every activities, i use only predicators indicating zero collinearity (P > 0.10).