I presented visual surveys for bumble bees at each of 7 internet from inside the exact same around three census attacks as we counted flowery money assortment (twenty eight Get so you can seven Summer, 22-31 June, 22-29 July). For every of your own three bumble bee studies, i went along to per site 3 times, immediately after through the each of three time symptoms (0800-1100, 1100-1300, 1300-1700 times). Most of the sampling was accomplished into the bright months having temperature between 19 and thirty-two°C.
We trapped and noted for each bumble-bee with a tiny mark off colored correction water into thorax to stop counting individuals more than once during a sample months on an online site. We recorded bumble bee variety, status, and also the plant variety on which this new bumble-bee was found foraging and you will create the newest bee. We spent 29 min for every visit during the a few internet sites which have a segmet of ?dos,000 meters 2 , 45 minute at a couple of ten,000-yards dos internet, ninety min on a couple of 29,000-yards dos internet sites, and 120 min at the several 70,000-meters 2 internet sites. We checked out to possess a sampling time prejudice having fun with rarefaction (come across Mathematical Studies)parisons regarding variety out of bees stuck hourly so you can resource values or environment types eliminated possible testing time biases.
I known bumble bees worldwide having fun with Mitchell (1962) since the a first expert; to possess definitions out of regional species, i utilized Medler and you may Carney (1963). Hendrix in the University of Iowa. New plant species was indeed later on classified while the native otherwise put so you’re able to get acquainted with whether the bumble bees, which can be indigenous, demonstrated choices for native flowering species.
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 Plants included on the list were those from which we captured bumble bees in this and related studies (C. Gienapp, unpublished data).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 out of bumble bee diversity and you will variety for each and every hr having fun with initial effortless regression analyses contrasting all of them from the percentage and you can LRI lijepe samohrane Еѕene Hrvatska of each and every private and you may combined surroundings varying ( Table 2) in the both five-hundred- and you will 700-meters radii and you can web site parameters (wealth, assortment, and you can thickness out of bumble bee-went to flowering ramets). Surroundings predictors demonstrating advantages, hence chosen for additional analyses was in fact LRI of surroundings within five hundred and you can 700 yards (with and you may without any webpages) as well as the percentage of shared grasslands about land ( Table dos). We chose to fool around with LRI viewpoints which have and you can without any site integrated to examine brand new cousin benefits out of floral sources of the new land and web site itself so you can variety and you may abundance and additionally the end result of landscaping and you may website combined. High web site predictors were Simpson diversity, wealth, and occurrence off flowering ramets out of bush kinds decided to go to by bumble bees.
Voucher specimens out-of bumble bees are in this new type of Stephen D
We used Pearson device-second relationship analyses to examine having collinearity ranging from possible predictors off bumble bee assortment and you can abundance each hour in advance of several regression data. Diversity, wealth, and you can density from flowering ramets at webpages just weren’t correlated into the LRI of the surroundings (having and you may with no webpages provided) in the five-hundred- otherwise 700-meters radii (every r 0.16). Although not, there clearly was weak collinearity between your site characteristics of occurrence and variety out-of blooming ramets out of kinds employed by bumble bees (r = 0.668, P = 0.07), and simply one among these a few local procedures out-of info try used in virtually any regression design. In every habits, we use only predicators exhibiting zero collinearity (P > 0.10).