US Forest Service Research & Development
Contact Information
  • US Forest Service Research & Development
  • 1400 Independence Ave., SW
  • Washington, D.C. 20250-0003
  • 800-832-1355
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Research Topics

Priority Areas

  • Forest Inventory and Analysis

The sites listed below are external or third-party sites which the Forest Service has provided for reference only.
Rachel Riemann

Rachel Riemann

Research Forester / Geographer
c/o USGS, 425 Jordan Road
New York
United States

Phone: 518-285-5607
Contact Rachel Riemann

Current Research

  • Fragmentation and urbanization of forest land: Working to continually improve our ability to monitor forest fragmentation and urbanization via metrics that are accurate, robust, relevant to known issues, and together completely describe the different spatial and context characteristics that are known to affect forest ecosystems. Research includes development of a suite of metrics from several sources to maintain over time, integrating it with existing forest inventory data, and collaborating on research to identify important thresholds and further understand the impact of each on forested ecosystems.  Resulting information is available and has been included in state reports, state planning efforts, and national assessments. 
  • Accuracy assessment of geospatial data: Developing an assessment protocol for continuous geospatial data that can take advantage of the wealth of the extensive FIA plot data to characterize accuracy in terms of the magnitude, extent, type, and location of error in the geospatial datasets.
  • Geospatial modeling of forest characteristics: Developing methods to generate geospatial datasets (digital maps) of forest characteristics with known uncertainties and increasing accuracy and spatial resolution.  The most recent generation of modeled datasets are archived and available, along with their comparative accuracy assessment.
  • Improving estimates of tree canopy cover: Using comparative assessment to understand the accuracy of GEOBIA vs. current FIA photointerpreted and field estimates of tree canopy cover and find ways to improve those estimates.
  • Science dissemination and community engagement: Developing online and hardcopy products and approaches for making research results and the online geospatial data we develop more accessible to all users, including planning, Extension, and educational communities.  Increasing interaction with user communities to develop these products.

Research Interests

What impacts are we having on the forest ecosystems we live with? How is is this changing forest ecosystems or affecting their resilience? How can our monitoring of forested areas best contribute to our understanding of those impacts? And help teach us how to plan, manage, or live in ways that increase forest sustainability and resilience and maintain the forest ecosystem benefits and services we need?   
Includes both continued research effort and continued support of community engagement, understanding and monitoring of ecosystem services, as an FIA-Tribal liaison, and in cross sector (gov't, university, NGO...) and cross-level (federal, state, municipal, landowner...) information sharing, collaboration, and co-production of knowledge.

Past Research

  • Developed an airphoto guide to identifying New England forest cover types
  • Investigated inventory protocols and assessed the amount of tree cover occurring in nonforest areas and thus being missed in an inventory of forest areas only. In cooperation with interested urban areas the Urban FIA program is now rapidly and formally adding the inventory of trees in urban areas to the FIA database.
Riemann Hershey, Rachel; Befort, William A. 1995. Aerial photo guide to New England forest cover types. Gen. Tech. Rep. NE-195. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 70 p.

Why This Research is Important

  • Forest fragmentation and urbanization affects sustainability of forest interior habitats; the ability of species to move through the landscape; the ease with which exotic, invasive or generalist species can gain a foothold; the ability of the forest to protect the quality and quantity of surface and ground water supplies; and the resiliency of forest ecosystems to adapt to pressures associated with climate change. It also affects outdoor recreation opportunities, types of forest management employed, forest products harvested, and local culture.
  • Maps and geospatial datasets of forest characteristics make forest inventory information more accessible without confidentiality issues, and provide modeled estimates of forest characteristics in areas where ground inventory information is non-existent or sparse.
  • Accuracy and uncertainty measures associated with geospatial datasets (digital maps) substantially increase their utility. Knowing the type, magnitude, and location of errors makes it easier to determine whether there is sufficient accuracy for a particular application, or incorporate uncertainty into subsequent modeling.
  • Tree canopy cover is an important factor for mitigating the effects of urbanization on water quality and quantity, characterizing potential wildlife habitat, supporting biomass and carbon stock estimates, and contributing to the calculation of ecosystem services provided by urban trees. Accurate canopy cover information could also screening and stratification procedures used to implement forest inventories in urban and other nonforest areas, improving cost-effectiveness and resulting estimates of tree resources in these highly spatially variable areas.
  • Science dissemination and communication: All of the above is of interest to a broader audience and wider range of uses than can currently readily access it. E.g. Maps of forest characteristics and associated summary information can be used by Extension and schools for education if packaged in accessible pieces.  Improved access to this information, via both online and hardcopy products, facilitates both extension education and classroom studies in topics including invasive species, water quality, and climate change impacts.



  • London School of Economics, M.Phil. Geography 1991
  • University of New Hampshire, M.S. Forestry 1987
  • Middlebury College, B.A. Ecology 1985

Professional Experience

  • Research Forester/Geographer, USDA Forest Service, Northern Research Station, Forest Inventory and Analysis
    1997 - Current
  • Forester/Geographer, USDA Forest Service, Northern Research Station, Forest Inventory and Analysis
    1992 - 1997

Featured Publications & Products


Citations of non US Forest Service Publications

  • Canham, C. D., L. Murphy, R. Riemann, R. McCullough, and E. Burrill. 2018. Local differentiation in tree growth responses to climate. Ecosphere 9(8):e02368. 10.1002/ecs2.2368

Research Highlights


Nationwide Datasets of Tree Species Distributions Created

Geospatial datasets of the relative abundance and distribution of individual tree species have been created by Forest Service scientists for 323 ...


Last updated on : 10/26/2020