Modeling The Effects Of Roadside And Meadow Foliage Management On The Dynamics Of Bombus Impatiens Populations

Populations of pollinators, including the common ground bumble bee Bombus impatiens, can suffer declines due to a lack of flower resources. Flower resources can be influenced by a variety of natural and anthropogenic factors. There is evidence that regimented foliage management significantly alters the availability of pollinator-relevant flowers. Here I report on field studies testing the effects of foliage management (mowing) on the abundance of five flowering plant species. I then outline a mathematical model based on B. impatiens life history to predict the impacts of mowing regimes on the bees’ population dynamics. I used flower phenology surveys to determine the inflorescence density of my five target flower species within two habitats under different foliage management regimes. Surveys indicated that cutting back foliage significantly reduced the number of inflorescences when species were pooled. When considered individually, only Solidago rugosa showed reduction due to mowing. I then incorporated inflorescence density data into mathematical projections of the total nectar produced within an explicit landscape under different hypothetical foliage management regimes. The outcomes of this model suggest that implementing mowing practices influence the ability of Bombus impatiens to produce new queens and thus to their ability to persist in relatively higher abundance.