Laura Burkle and her colleagues captured 2,778 bees while retracing the muddy steps of a scientist who studied the interactions between bees and flowering plants more than a century ago.

Occasionally stung, but considering herself lucky to have access to the rich historic records that guided her field work, the Montana State University ecologist and her collaborators have now published their results in the prestigious journal, Science.

"It's exciting," Burkle said as the Feb. 28 publication date approached.

Burkle conducted her bee study in the forests of southern Illinois while she was a postdoctoral researcher at Washington University in St. Louis, Mo. Now at MSU for the past two years and planning a major ecological study between Yellowstone National Park and Glacier National Park, Burkle and her co-authors compared the bees and flowering plants that existed in 2009 and 2010 with those that existed in the late 1800s and early 1900s around Carlinville, Ill.

(See related: Pesticides on brink of ban over honey bee losses)

The researchers discovered that the area has lost many species of bees and flowering plants over the 120 years since professor Charles Robertson first surveyed the area, Burkle said. Also lost were many interactions between the bees and flowers.

Despite the loss, however, the bees and plants have been surprisingly resilient in the face of warmer temperatures and changing land use, Burkle said. The forests that once grew 10 miles outside of Carlinville are fragments of what they were when Robertson drove his horse and buggy to collect specimens. Fields of corn have replaced acres of trees and prairie. Natural areas have been converted to agricultural, commercial or residential uses. Winter and spring temperatures have risen an average of 3.6 degrees Fahrenheit.

"The good news is that these systems and the way they are structured make them really resilient to change," Burkle said. "But there's been so much change that resiliency has been compromised."

Co-author Tiffany Knight, Burkle's faculty adviser for the study, said, "Plants are an important resource for humans, providing food, fiber and the backbone for all other ecosystem services. Most plants rely on animal pollinators for their reproduction. There is concern that human changes to the environment are disrupting plant-pollinator interactions, but our study is the first that has been able to look at this problem using historical data.

(See related: Honey bee losses defy solitary explanations)