Range time sampling prejudice try checked-out from the evaluating counted variety fullness from websites having rarefacted variety fullness. Regarding the rarefaction analysis, i place take to proportions from the 21 people, that lower than the minimum amount discovered at your website which have the fresh fewest bumble bees. Rating buy regarding types richness towards the web sites stayed a similar except for Solon Prairie, and this decreased a couple places inside cousin review, demonstrating little aftereffect of testing efforts into types richness.
Species richness ranged from five to eight species per site, and log2 Shannon-Wiener diversity across the eight sites ranged from 2.05 to 2.69. Five species common to all sites were B. bimaculatus Cresson, B. impatiens Cresson, B. pensylvanicus (DeGeer), B. auricomus (Robertson), and B. griseocollis (DeGeer), but the abundance of individuals among bumble bee species differed greatly between sites ( Fig. 1). We observed bumble bees on 43 of the 150 flowering species found at the sites. The percentage of native plant species among the 43 species visited was similar to their overall percentage in the combined flora of the sites (80 versus 77%, respectively). All of the plants on which bees were caught were herbaceous perennials or shrubs, except for one annual species (Melilotus alba L.).
The fresh new proportional shipment away from wealth of every bumble bee species within every one of seven high lawn prairie websites in eastcentral Iowa. Select Table 1 to possess webpages identity abbreviations.
Normally, the fresh new surroundings encompassing the sites try ruled by corn and you can soybean row plants (41%), which have a supplementary 31% consisting of shared grasslands (fallow and you can grazed pastures, alfalfa, etc.) and you may 17% shared forest. Of your five mutual landscape categories, grasslands provided typically 51% of your complete LRI well worth. However, the new portion of some other surroundings kinds differed considerably around the internet. For example, from the 700-meters distance, elements instead of flowery info as well as farming sphere, courses, and you may ponds, taken into account nearly 85% of your surroundings surrounding Sioux Method, but just ?5% of the Poultry Creek landscaping. Furthermore, 40% of one’s landscaping during the Poultry Creek try forest, whereas Solon Prairie’s land had Table 4; Fig. 2). At five hundred-yards radius, this new LRI of your own grasslands and also the abundance off bumble-bee-visited information in the web site had been both tall on the model anticipating bumble-bee diversity; on 700 yards, the fresh explanatory stamina of the design decreased ?10%, and you will while the latest LRI regarding grasslands is significant, the latest abundance out-of bumble bee-utilized floral info within webpages only showed a trend in the the fresh design. Brand new proportion of variance told me from the LRI of your grasslands is two to three minutes that of wealth out of bumble bee info at the webpages at a couple more radii ( Fig. 3a). Whenever thickness of flowering ramets was replaced with variety regarding more than activities, thickness did not contribute somewhat into models (all the P > 0.50). We together with written patterns where i changed the brand new LRI away from the grasslands for the part of this new landscape inside the grassland surrounding but not for instance the webpages to determine whether or not it cruder scale out of information was adequate to anticipate range. During the 700-m radius, the fresh design using % grasslands is actually extreme, although explanatory energy of the design was less than the fresh new design using the LRI of grasslands. New model playing with percent grasslands during the five-hundred meters wasn’t significant (r 2 = 0.55, P = 0.087).