The HEMS Study

Hemlock Ecosystem Management Study (HEMS)
Hemlock Undergraduate Research at Unity College 

The HEMS research team uses experimental treatments in the field to measure the effects of logging and slow dying trees.

The Hemlock Ecosystem Management Study is a multi-year study of how the loss of eastern hemlock trees affects ecosystems and people in Maine. Mature hemlock trees create unique aesthetic and environmental conditions in forests, and these trees are now facing infestation by the hemlock woolly adelgid (HWA). These small, aphid-like insects can kill a mature hemlock in as few as three years by sucking the sap from the tender hemlock shoots. The first evidence of the existence of the HWA in Maine was in 2003.

The project is directed by four primary faculty members: Amy Arnett and Erika Latty from the Center for Biodiversity; and Kathleen Dunckel and Brent Bibles from the Center for Natural Resource Management and Protection. Integrated across multiple biological disciplines (entomology, forest ecology, botany, wildlife impacts), and across broader disciplinary boundaries (biological sciences, remote sensing and GIS, sociology, economics, and education), the study looks at influences in ecosystem function and socioeconomic parameters. Students are involved in the study in a number of ways, and recently one research student used GIS to characterize environmental gradients which will in turn help anticipate where HWA infestations will occur. This student had the opportunity to present his findings at three regional conferences last year. 

The HEMS research team uses experimental treatments in the field to measure the effects of logging and slow dying trees. Remote sensing and Geographic Information Systems (GIS) are used to map the distribution of hemlock-dominant stands across Maine. The team investigates how plant and animal biodiversity change in response to these variables, and their research helps land managers understand what kind of forest to expect after hemlock forest disturbances.  The research also helps agencies/organizations decide what to do with public or preserved lands that may become infested with the HWA. Information provided by the HEMS team gives stakeholder groups the ability to make informed decisions.