I held visual surveys getting bumble bees at each of your own seven websites inside the exact same around three census episodes while we measured flowery money diversity (twenty eight May to 7 Summer, 22-31 June, 22-29 July). Per of your own three bumble-bee surveys, we visited for every website three times, immediately after throughout all of three time symptoms (0800-1100, 1100-1300, 1300-1700 occasions). Every sampling are achieved with the sunny months having temperature between 19 and you will 32°C.
I trapped and you will noted for each and every bumble-bee with a small dot off colored correction liquid on thorax to stop relying people over and over again throughout a sample months at the a site. We filed bumble-bee variety, status, and the plant kinds about what the fresh bumble bee is located foraging and create the fresh bee. We invested 31 minute for every see at two internet sites that have an area of ?dos,000 m 2 , 45 min at the two 10,000-m 2 internet sites, 90 minute at several 30,000-yards dos internet, and you can 120 min on a few 70,000-yards 2 web sites. I examined to possess a sample day prejudice having fun with rarefaction (get a hold of Statistical Investigation)parisons out-of wealth out-of bees trapped hourly so you can funding thinking or environment items removed potential sampling big date biases.
I understood bumble bees in this field playing with Mitchell (1962) due to the fact a primary power; to have meanings regarding local varieties, we made use of Medler and you may Carney (1963). Hendrix during the College away from Iowa. New bush varieties had been after classified while the indigenous otherwise lead so you’re able to learn whether the bumble bees, that are local, demonstrated preferences for local flowering kinds.
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 Plants included on the list were those from which we captured bumble bees in this and related studies (C. Gienapp, unpublished data).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 recognized possible predictors out of bumble-bee assortment and you can variety per hour having fun with preliminary simple regression analyses contrasting all of them against the commission and you will LRI of any private and you can joint landscape varying ( Dining table 2) on one another 500- and you will 700-yards radii and you may website variables (abundance, assortment, and you may occurrence of bumble bee-decided to go to flowering ramets). Landscape predictors indicating value, which chosen for additional analyses was indeed LRI of your landscape in the five-hundred and you Hyderabad in India wives can 700 meters (having and you will without having any web site) as well as the percentage of mutual grasslands regarding landscape ( Desk 2). I decided to fool around with LRI viewpoints which have and you will without having any web site integrated to examine brand new cousin efforts of flowery types of the fresh new landscaping and you can website alone to help you variety and you will wealth and additionally the end result of one’s surroundings and you can web site mutual. Significant web site predictors was indeed Simpson range, variety, and thickness regarding blooming ramets of bush species decided to go to of the bumble bees.
Coupon specimens out-of bumble bees come in the fresh type of Stephen D
I put Pearson product-minute relationship analyses to look at to have collinearity between possible predictors out of bumble-bee range and wealth by the hour prior to multiple regression analysis. Variety, wealth, and you will occurrence away from blooming ramets in the web site weren’t synchronised towards LRI of the landscaping (having and you will without the web site included) during the five hundred- or 700-yards radii (every r 0.16). not, there was weakened collinearity within site characteristics out-of occurrence and you can wealth out of flowering ramets regarding varieties utilized by bumble bees (roentgen = 0.668, P = 0.07), and only one of these a couple of local measures out of tips are utilized in any given regression model. Throughout models, i only use predicators showing zero collinearity (P > 0.10).