Fig 1.
Density map of North Dakota registered apiaries (ND Department of Agriculture, 2014) from the year 2014.
A 30x30 m raster grid was created where the value for each pixel represents the number of registered apiaries within a 15-km radius. Red pixels represent zones of the highest density. Black polygons distinguish North Dakota counties.
Table 1.
Insecticides, their class, and primary mode of application included in this study.
Fig 2.
Eight insecticides average total use (kg) per site and their trends within 1.6 km of registered apiaries from 2001–2014.
The upper panels show each insecticide’s use percent on wheat (red), soybeans (blue) and corn (red). Data points with zero uses were treated as missing values and were removed from each regression.
Fig 3.
Difference in Quality Index (QI) scores from 2006–2014 surrounding North Dakota apiaries.
A) The change in QI scores between 2006–2014 on lands within 1.6 km of registered apiary sites in North Dakota. Negative values (red) and positive values (blue) indicate decreasing and increasing QI scores, respectively; B) Example of changing QI from 2006–2014 in Stutsman County North Dakota, where grasslands hosting several apiary sites in 2006 were converted to cropland in 2014; C) Example of changes in QI and DI for individual site with red and green values indicating low and high quality habitat, respectively, from 2006 and 2014.
Fig 4.
Degradation Index (DI) outputs from InVEST model within apiary site 1.6-km buffers.
Pixels that have the high, low, and minimal (ranging from 0 to 1.0 changes are represented as red, yellow, and dark grey, respectively. The light grey regions did not have registered apiaries.