I conducted visual surveys to have bumble bees at each and every of seven web sites in the same about three census symptoms once we mentioned floral resource range (twenty eight May so you’re able to seven June, 22-31 June, 22-31 July). Per of your about three bumble-bee surveys, i went along to for every web site 3 times, just after throughout the all of three time symptoms (0800-1100, 1100-1300, 1300-1700 circumstances). The testing is accomplished into the warm months that have heat anywhere between 19 and you may thirty-two°C.
I stuck and you will noted for every single bumble bee having a small mark off colored modification water on the thorax to stop depending some body more often than once through the a sampling months in the a web page. We registered bumble bee types, status, therefore the bush species on what the fresh new bumble-bee was discover foraging and create the latest bee. I invested 31 minute each visit in the two sites having a segmet of ?dos,000 meters 2 , forty-five minute at the a few 10,000-meters dos web sites, 90 min within a few 29,000-m dos web sites, and 120 minute from the a couple 70,000-meters 2 websites. We checked-out to own a sampling date prejudice having fun with rarefaction (get a hold of Analytical Data)parisons from variety regarding bees trapped by the hour so you’re able to capital beliefs otherwise habitat items got rid of possible sampling time biases.
We identified bumble bees on the planet playing with Mitchell (1962) just like the a first power; to have meanings of local varieties, we utilized Medler and you can Carney (1963). Hendrix during the College or university out-of Iowa. This new bush kinds have been afterwards categorized just like the local otherwise delivered to get acquainted with whether or not the bumble bees, which can be native, presented preferences having local 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 Plants included on the list were those from which we captured bumble bees in this and related studies (C. Gienapp, unpublished data).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 understood potential predictors from bumble bee range and you can variety per time having fun with preliminary effortless regression analyses contrasting them contrary to the commission and you can LRI of each and every seksikäs Ukraina tytöt personal and you will shared land variable ( Dining table dos) from the both five hundred- and you will 700-meters radii and webpages parameters (abundance, assortment, and you can thickness out-of bumble bee-went along to blooming ramets). Land predictors showing benefit, hence chosen for further analyses was in fact LRI of the surroundings from the five hundred and 700 meters (that have and without any web site) together with portion of joint grasslands regarding landscape ( Dining table 2). We made a decision to use LRI beliefs which have and you may with no site provided to examine this new cousin contributions out-of flowery sources of the new surroundings and you may website by itself so you can assortment and you can variety also the outcome of land and you will website combined. Extreme site predictors was indeed Simpson assortment, abundance, and you may density out of flowering ramets from bush species visited by bumble bees.
Coupon specimens of bumble bees come in the brand new line of Stephen D
We utilized Pearson product-minute relationship analyses to examine getting collinearity anywhere between possible predictors off bumble bee diversity and you can wealth per hour just before numerous regression data. Assortment, variety, and you will thickness off flowering ramets in the webpages just weren’t synchronised on the LRI of landscaping (with and without any website included) within five-hundred- or 700-yards radii (the r 0.16). However, you will find poor collinearity between your webpages characteristics away from density and you can wealth of blooming ramets regarding types employed by bumble bees (r = 0.668, P = 0.07), and only one among these two regional steps off info are used in any given regression design. In all habits, we just use predicators proving zero collinearity (P > 0.10).
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