We seized a maximum of 943 bumble bees belonging to seven species
Collection day testing bias was checked because of the researching measured varieties richness off internet having rarefacted varieties fullness. From the rarefaction study, i place decide to try proportions within 21 people, one to lower than minimal count discovered at the website with this new fewest bumble bees. Rank buy regarding varieties richness towards sites stayed an equivalent apart from Solon Prairie, and this diminished a couple of cities inside the relative rating, appearing nothing effect of testing effort into the kinds richness.
Overall performance
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 newest proportional shipments of wealth of any bumble bee kinds at the every one of 7 significant lawn prairie internet when you look at the eastcentral Iowa. Select Desk 1 getting site name abbreviations.
New LRI of the done landscape that have and you may without any website integrated including displayed high consequences to the bumble bee diversity ( Desk 4) however, were not high advancements along side design that have grasslands LRI and wealth
On average, the brand new landscape encompassing the websites try dominated from the corn and soybean line plants (41%), that have an extra 31% consisting of joint grasslands (fallow and you will grazed pastures, alfalfa, etc.) and you can 17% joint woodland. Of your own four joint landscaping classes, grasslands provided an average of 51% of one’s overall LRI value. But not, the newest portion of other landscaping classes differed significantly around the internet. Such, during the 700-m radius, parts as opposed to flowery tips as well as agricultural areas, channels, and ponds, taken into account nearly 85% of the land related Sioux Path, but just ?5% of one’s Turkey Creek surroundings. Likewise, 40% of landscape within Chicken Creek try woodland, while Solon Prairie’s landscaping got Desk cuatro; Fig. 2). From the five hundred-yards distance, the newest LRI of grasslands together with variety off bumble bee-visited tips within webpages was in fact one another extreme in the design predicting bumble bee range; on 700 m, the explanatory stamina of one’s design diminished ?10%, and whereas the LRI out of grasslands was high, the abundance out of bumble bee-utilized floral information on webpages simply demonstrated a trend from inside the the model. New ratio of your variance explained by LRI of one’s grasslands try two to three times that abundance from bumble bee tips within website during the several more radii ( Fig. 3a). Whenever thickness regarding flowering ramets are substituted for wealth throughout the significantly more than activities, density don’t lead significantly to your designs (all of the P > 0.50). We and additionally composed models in which i replaced brand new LRI off the newest grasslands on the portion of the chat with Metro brides brand new land in the grassland surrounding but not for instance the webpages to choose if this cruder measure off resources are enough to predict range. At 700-m radius, the design having fun with per cent grasslands are significant, nevertheless the explanatory power of your design are lower than the fresh new model making use of the LRI out-of grasslands. The new model having fun with % grasslands at the 500 meters was not significant (r 2 = 0.55, P = 0.087).
