We presented artwork studies to have bumble bees at every of your 7 sites in the exact same about three census attacks even as we measured flowery financing range (twenty-eight May so you can 7 June, 22-29 June, 22-31 July). For each of your three bumble-bee studies, we visited for every site 3 x, immediately following throughout all of three-time periods (0800-1100, 1100-1300, 1300-1700 times). Every testing was carried out towards bright weeks that have heat anywhere between 19 and you can thirty-two°C.
I stuck and you will designated for each and every bumble bee having a small mark of colored correction water on the thorax to avoid depending anybody more often than once throughout the a sampling period at the a web page. I registered bumble-bee varieties, status, and the plant kinds on which the fresh bumble-bee is discover foraging and you may released the newest bee. I invested 31 min per go Makassar bride price to within several websites that have an area of ?2,000 m 2 , forty five minute at the a few ten,000-yards 2 sites, 90 minute on one or two 30,000-yards dos sites, and you can 120 minute at the two 70,000-meters dos internet. We checked out getting a sample time bias having fun with rarefaction (pick Statistical Investigation)parisons of abundance off bees trapped by the hour to help you capital philosophy otherwise environment models eliminated prospective sampling date biases.
We known bumble bees in the world having fun with Mitchell (1962) since a first expert; having definitions away from regional species, i put Medler and you can Carney (1963). Hendrix during the College or university off Iowa. The fresh new plant types was later classified because local otherwise introduced to help you analyze if the bumble bees, which are local, presented needs to own local blooming variety.
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 Plants included on the list were those from which we captured bumble bees in this and related studies (C. Gienapp, unpublished data).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 identified prospective predictors off bumble-bee variety and you may wealth for every single hour having fun with preliminary simple regression analyses contrasting all of them contrary to the commission and LRI of every personal and you may shared landscape variable ( Table 2) at each other five hundred- and you may 700-meters radii and you will webpages parameters (wealth, assortment, and you may thickness of bumble-bee-decided to go to flowering ramets). Surroundings predictors showing value, and this chose for additional analyses had been LRI of the surroundings at five-hundred and 700 m (with and you will without the website) additionally the percentage of joint grasslands on landscape ( Table dos). I decided to play with LRI opinions having and you may with no site included to look at the relative benefits off flowery resources of the newest surroundings and you can web site by itself so you can range and you can wealth and the outcome of your own landscape and you may web site shared. High webpages predictors was Simpson assortment, wealth, and you will thickness out-of blooming ramets out-of plant species decided to go to from the bumble bees.
Discount specimens out-of bumble bees come into the collection of Stephen D
I used Pearson product-moment correlation analyses to examine to have collinearity anywhere between possible predictors off bumble-bee assortment and you will abundance each hour just before numerous regression investigation. Diversity, wealth, and occurrence from flowering ramets during the web site just weren’t coordinated towards the LRI of the landscape (having and you will without the web site included) from the five-hundred- or 700-m radii (the r 0.16). But not, there is certainly weakened collinearity within site qualities away from density and you may wealth out-of flowering ramets out of species employed by bumble bees (roentgen = 0.668, P = 0.07), and just one among these a couple of local actions out of tips are found in virtually any regression design. In most patterns, i just use predicators showing zero collinearity (P > 0.10).