At each head to, i moved the whole site and sought bumble bees toward flowering plants

I held visual studies getting bumble bees at every of 7 internet during the exact same three census episodes once we measured floral money variety (28 May in order to seven June, 22-31 June, 22-29 July). For each and every of about three bumble-bee surveys, we went along to for each and every vruД‡e GrДЌka Еѕene website 3 times, after throughout the every one of three time symptoms (0800-1100, 1100-1300, 1300-1700 occasions). All testing is actually carried out for the bright days having temperature between 19 and you can thirty-two°C.

I trapped and you can designated for each and every bumble-bee which have a tiny dot away from coloured correction liquid towards thorax to eliminate relying somebody more than once through the a sampling several months at a site. I registered bumble bee varieties, status, and the bush varieties about what new bumble-bee is actually receive foraging and you will create brand new bee. I spent 29 minute for every head to in the a couple of internet sites with a segmet of ?2,000 meters dos , 45 min at a few 10,000-meters dos websites, 90 min at the a couple 30,000-meters dos websites, and you can 120 minute at two 70,000-yards dos internet. We checked for a sampling big date bias playing with rarefaction (discover Mathematical Investigation)parisons off variety away from bees caught per hour to help you money viewpoints or environment versions got rid of potential testing big date biases.

I recognized bumble bees worldwide playing with Mitchell (1962) because the a primary authority; to own meanings regarding regional types, we used Medler and Carney (1963). Hendrix in the University off Iowa. The plant varieties were afterwards classified as the native or lead in order to familiarize yourself with whether the bumble bees, that are indigenous, shown needs for indigenous flowering varieties.

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 Plants included on the list were those from which we captured bumble bees in this and related studies (C. Gienapp, unpublished data).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 recognized prospective predictors regarding bumble bee assortment and you may variety for each and every hr having fun with initial simple regression analyses contrasting all of them resistant to the percentage and you will LRI of each and every private and you will shared land adjustable ( Dining table dos) on one another five hundred- and you will 700-meters radii and web site variables (abundance, assortment, and you will occurrence out-of bumble bee-visited flowering ramets). Landscaping predictors appearing importance, and that chosen for additional analyses was basically LRI of surroundings from the 500 and you will 700 meters (having and you may without having any webpages) together with portion of joint grasslands regarding land ( Table 2). We made a decision to fool around with LRI opinions with and you may with no site provided to look at brand new relative benefits off flowery sources of the landscape and webpages by itself so you can variety and you will wealth in addition to the result of your land and you will site combined. High website predictors was Simpson range, abundance, and thickness out of flowering ramets of plant varieties went to by bumble bees.

Coupon specimens away from bumble bees come in the new type of Stephen D

I used Pearson device-moment relationship analyses to look at for collinearity between potential predictors off bumble bee variety and you will wealth each hour ahead of multiple regression investigation. Assortment, variety, and occurrence regarding flowering ramets on site weren’t synchronised with the LRI of one’s surroundings (with and without having any webpages provided) on 500- otherwise 700-yards radii (every roentgen 0.16). Although not, you will find poor collinearity between the website attributes off density and abundance away from blooming ramets of types used by bumble bees (r = 0.668, P = 0.07), and only one a couple of local methods regarding resources are utilized in a regression design. Throughout habits, we only use predicators proving zero collinearity (P > 0.10).