At each and every see, i strolled the complete webpages and you will sought bumble bees into the flowering herbs


At each and every see, i strolled the complete webpages and you will sought bumble bees into the flowering herbs

I held graphic studies to possess bumble bees at each and every of eight web sites in the exact same around three census symptoms once we measured floral money variety (twenty eight Will get datiraju vruД‡e Еѕene iz Francuski-a so you can 7 Summer, 22-30 Summer, 22-29 July). Per of the about three bumble-bee surveys, i went to for every single webpages 3 x, after during all of three-time periods (0800-1100, 1100-1300, 1300-1700 instances). The sampling are carried out towards sunny months with temperature ranging from 19 and 32°C.

We caught and you may marked for each bumble-bee having a little mark out-of colored modification fluid to the thorax to end depending someone more often than once during a sample several months within an online site. I submitted bumble-bee species, status, together with bush types on which the brand new bumble bee is found foraging and you will put-out new bee. We invested 30 minute for each and every check out within a few web sites with a segmet of ?2,000 m 2 , forty five min on a few ten,000-yards dos internet, 90 minute at the a few 31,000-yards dos sites, and you will 120 min in the one or two 70,000-m 2 sites. I looked at having a sample go out bias using rarefaction (discover Analytical Research)parisons regarding variety from bees stuck hourly so you can funding philosophy otherwise environment items got rid of potential testing date biases.

I recognized bumble bees on the planet having fun with Mitchell (1962) since a primary expert; to possess descriptions regarding local types, i made use of Medler and you will Carney (1963). Hendrix from the College or university from Iowa. The fresh new bush variety was in fact after categorized while the native or lead to get acquainted with if the bumble bees, which happen to be native, demonstrated preferences to have indigenous flowering types.

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 recognized potential predictors away from bumble bee range and variety for each hour having fun with original simple regression analyses evaluating them up against the percentage and you may LRI of each and every individual and you may combined landscape varying ( Desk 2) from the both 500- and you will 700-m radii and you may webpages parameters (abundance, variety, and you may thickness of bumble-bee-went to blooming ramets). Surroundings predictors proving benefit, hence picked for additional analyses was LRI of the surroundings in the 500 and 700 yards (with and you can without the webpages) as well as the portion of joint grasslands in the land ( Desk 2). We chose to fool around with LRI viewpoints that have and you can without any website included to examine the new cousin efforts off flowery sourced elements of the fresh landscape and website in itself so you’re able to variety and you will abundance and additionally the effect of one’s landscaping and you can site mutual. Tall site predictors had been Simpson range, abundance, and you will thickness away from blooming ramets regarding plant types visited by the bumble bees.

Coupon specimens from bumble bees have the latest collection of Stephen D

I used Pearson product-minute relationship analyses to examine getting collinearity ranging from potential predictors away from bumble-bee variety and you can variety per hour just before several regression analysis. Diversity, wealth, and occurrence away from blooming ramets from the site just weren’t coordinated towards the LRI of your own surroundings (with and you may without any site provided) at five-hundred- or 700-m radii (all of the roentgen 0.16). But not, there is weak collinearity involving the website characteristics from thickness and you may wealth of blooming ramets out-of varieties employed by bumble bees (roentgen = 0.668, P = 0.07), and only one among these two local methods off resources is found in virtually any regression design. In every activities, we use only predicators demonstrating no collinearity (P > 0.10).


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