I conducted visual surveys to have bumble bees at each and every of one’s seven internet sites when you look at the exact same around three census symptoms while we measured flowery financial support variety (twenty eight Can get so you can seven June, 22-29 June, 22-29 July). Each of one’s around three bumble bee surveys, we went along to for every single site three times, immediately after throughout the every one of three time episodes (0800-1100, 1100-1300, 1300-1700 instances). All the sampling is actually achieved toward sunny days with heat ranging from 19 and thirty two°C.
We stuck and you may marked for every single bumble-bee with a small dot of colored modification water toward thorax to cease depending anybody more often than once throughout the a sample months within a website. We filed bumble bee kinds, status, while the plant varieties on which the new bumble bee was discover foraging and you may put out this new bee. We invested 30 minute per head to during the one or two internet which have an area of ?dos,000 meters 2 , forty five min at the several 10,000-yards 2 internet, ninety min during the two 30,000-yards dos internet, and you will 120 minute from the several 70,000-yards dos sites. I tested to have a sample day bias having fun with rarefaction (discover Analytical Investigation)parisons regarding variety from bees trapped per hour so you can investment viewpoints otherwise habitat designs removed possible testing time biases.
I known bumble bees around having fun with Mitchell (1962) as a first power; to have definitions out of regional varieties, i utilized Medler and you can Carney (1963). Hendrix from the College or university regarding Iowa. Brand new bush variety had been later classified just like the native or put so you’re able to get acquainted with perhaps the bumble bees, which are local, displayed needs having local flowering species.
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 Plants included on the list were those from which we captured bumble bees in this and related studies (C. Gienapp, unpublished data).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.
We understood potential predictors off bumble-bee range and you will wealth for every single hours having fun with original simple regression analyses evaluating all of them from the payment and you may LRI of each individual and you can mutual landscape varying ( Table dos) on each other 500- and you will 700-yards radii and you will website details (wealth, diversity, and you can thickness away from bumble bee-decided to go to blooming ramets). Landscaping predictors showing importance, which chose for further analyses were LRI of your own surroundings within five hundred and you may 700 yards (having and you may with no web site) therefore the part of joint grasslands in the landscaping ( Dining table 2). We chose to use LRI opinions that have and you may with no web site integrated to look at this new relative efforts out of floral resources of the surroundings and you may site in itself so you’re able to diversity and you may wealth plus the result of your own surroundings and you may web site mutual. Tall site predictors was Simpson variety, abundance, and you will thickness from blooming ramets out-of plant varieties went to of the bumble bees.
Discount specimens away from bumble bees come in this new type of Stephen D
I made use of Pearson unit-time relationship analyses to examine for collinearity anywhere between possible predictors of bumble-bee range and you can wealth by the hour prior to several foreign brides Bandung regression studies. Assortment, variety, and you will density away from flowering ramets in the site just weren’t synchronised into LRI of land (which have and without any webpages included) at the 500- or 700-meters radii (every r 0.16). not, there can be weakened collinearity between your website properties away from occurrence and you will wealth of flowering ramets out-of varieties used by bumble bees (roentgen = 0.668, P = 0.07), and just one among these a couple of local strategies off tips is included in virtually any regression model. In every patterns, we only use predicators indicating zero collinearity (P > 0.10).