LEMMA Team Detail

Emilie Henderson Former position: Research Ecologist Dept. of Forest Ecosystems and Society Oregon State University

Educational Background

BA (Biology) Williams College, 1996
MS (Forest Science) Oregon State University, 2000
PhD (Forestry) University of Wisconsin-Madison, 2006

Research Interests

Disturbances such as human land-use can have persistent (and sometimes unintended) effects on forested ecosystems with respect to local plant community composition and soil properties, and also landscape-scale patterns in vegetation. Understanding the complex relationships between disturbance history, soil and plant communities at multiple scales is the common theme that has directed her research career to this date.

Biography

Emilie was a postdoctoral researcher with the LEMMA group from 2006 to 2009. She began her ecology career with an undergraduate honors project studying spring ephemeral wildflower communities as they relate to historic land-use in the Berkshire Mountains of Massachusetts. As a Master's student, she studied soil ecology (microarthropods grazing on fungi) in the context of prescribed fires in eastern Oregon's ponderosa pine forests. For her PhD, she integrated those interests studying the long-term effects of disturbances (farming, and fire) on plant communities, basic soil properties and landscape structure in the Northwest Sands of Wisconsin. Emilie's work with LEMMA focused on mapping Nature Serve's Ecological Systems classification across western Oregon using Random Forest models, and evaluating modeling tools and techiques for the Nationwide Forest Imputation Study (NaFIS). Outside of work, she spends her time visiting friends and family in and around Portland, dancing (mostly contra), hiking and playing Celtic music on her three harps.

Refereed Publications

	Ohmann, JL, MJ Gregory, EB Henderson, HM Roberts. 2011. Mapping gradients of community composition with nearest-neighbour imputation: extending plot data for landscape analysis. Journal of Vegetation Science 22(4):660-676.
	Grossmann, EB, DJ Mladenoff. 2008. Farms, fires, and forestry: Disturbance legacies in the soils of the Northwest Wisconsin (USA) Sand Plain. Forest Ecology and Management 256(4):827-836.
	Grossmann, EB, DJ Mladenoff. 2007. Open woodland and savanna decline in a mixed-disturbance landscape (1938 to 1998) in the Northwest Wisconsin (USA) Sand Plain. Landscape Ecology 22(1):43-55.

Technical Reports

	Grossmann, EB, JL Ohmann, J Kagan, HK May, MJ Gregory. 2010. Mapping ecological systems with a random forest model: tradeoffs between errors and bias. USGS Gap Analysis Bulletin, No. 17; February 2010; pp 16-22.
	Grossmann, EB, JL Ohmann, MJ Gregory, HK May. 2009. Nationwide Forest Imputation Study (NaFIS) - Western Team final report. Final Report of the Nationwide Forest Imputation Study (NaFIS).
	Grossmann, EB, J Kagan, JL Ohmann, HK May, MJ Gregory, C Tobalske. 2008. Final report on land cover mapping methods, map zones 2 and 7, Pacific Northwest ReGAP. Institute for Natural Resources, Oregon State University, Corvallis, OR.

Other Non-Refereed Publications

	Grossmann, EB. 2006. Post-settlement changes in the Northwest Wisconsin Sand Plain: Vegetation, soil and the landscape mosaic. Doctoral Thesis; University of Wisconsin-Madison.
	Grossmann, EB. 2000. Prescribed fire in Eastern Oregon ponderosa pine forests: relationships between soil fertility and ecology. Master's Thesis; Oregon State University.

Presentations

	Gregory, MJ, JL Ohmann, HM Roberts, HSJ Zald, EB Henderson. 2013. Recent advances and applications of nearest neighbors methods for regional-scale forest vegetation mapping in the Pacific Northwest, USA. Landcare Research Seminar: Lincoln, New Zealand; February 2013.
	Zald, HSJ, JL Ohmann, HM Roberts, M Gregory, EB Henderson, R McGaughey, RE Kennedy, J Braaten, M Simpson. 2013. Incorporating LiDAR and Landsat disturbance history into nearest neighbor mapping of vegetation composition and structure. USFS Region 6 office for Monitoring Inventory Mapping and LiDAR (MIML) working group: Portland, OR; February 2013.
	Henderson, EB, JL Ohmann, MJ Gregory, HM Roberts, HSJ Zald. 2012. All for one or one for all? Mapping many species individually versus simultaneously with random forest. Ecological Society of America Annual Conference: Portland, OR; August 2012.
	Gregory, MJ, EB Grossmann, JL Ohmann, HM Roberts. 2010. The Nationwide Forest Imputation Study (NaFIS): Challenges, results and recommendations from the western United States. Forest Inventory and Analysis Science Symposium: Knoxville, TN; October 2010.
	Ohmann, JL, MJ Gregory, HK May, EB Grossmann. 2010. Nearest neighbor mapping of vegetation gradients for landscape analysis and planning. 53rd International Symposium of the International Association for Vegetation Science: Ensenada, Mexico; April 2010.
	Grossmann, EB, JL Ohmann, MJ Gregory, HK May. 2009. Gradients or hierarchies? Which assumptions make a better map?. US Regional Association of the International Association of Landscape Ecology Annual Meeting: Snowbird, UT; April 2009.
	Grossmann, EB, JL Ohmann, MJ Gregory, HK May. 2009. Regional vegetation mapping: Making sense of the methods. Workshop on remote sensing for land managers: Redding, CA; June 2009.
	Grossmann, EB, JL Ohmann, MJ Gregory, HK May. 2009. Bringing our best data into conservation and restoration planning. California Klamath-Siskiyou Fire Learning Network Workshop: Weaverville, CA; July 2009.
	Grossmann, EB, JL Ohmann, MJ Gregory, HK May. 2009. Regional vegetation - methods behind the maps: Gradient Nearest Neighbor and random forest modeling. Information Sharing Workshop, Bureau of Land Management: Salem, OR; April 2009.
	Gregory, MJ, JL Ohmann, EB Grossmann, HK May. 2008. Spatial scaling effects of inventory reference data on nearest neighbor model predictions. Forest Inventory and Analysis Symposium: Park City, UT; October 2008.
	Gregory, MJ, JL Ohmann, HK May, EB Grossmann, KB Pierce Jr., TM Holt, JS Fried. 2008. Recent advances and applications of nearest neighbors methods for regional-scale forest vegetation modeling. Department of Forest Science Seminar: Corvallis, OR; April 2008.
	Grossmann, EB, JL Ohmann, J Kagan, KB Pierce Jr., HK May, MJ Gregory. 2008. Random forests and nearest neighbors: Methods for mapping the West Cascades of Oregon. US Regional Association of the International Association of Landscape Ecology Annual Meeting: Madison, WI; April 2008.
	Grossmann, EB, JL Ohmann, MJ Gregory, HK May. 2008. Is the World a Gradient, or a Hierarchy of Thresholds? Imputing Forest Composition and Structure Variables in the Pacific Northwest. Forest Inventory and Analysis Symposium: Park City, UT; October 2008.
	Ohmann, JL, M Moeur, M Hemstrom, T Burcsu, J Merzenich, MJ Gregory, HK May, EB Grossmann. 2008. Integrating forest inventory data, vegetation maps, and models of vegetation dynamics to support landscape analysis and planning: the IMAP story. Forest Inventory and Analysis Symposium: Park City, UT; October 2008.
	Ohmann, JL, MJ Gregory, HK May, EB Grossmann. 2008. Gradient Nearest Neighbor (GNN) maps of forest vegetation: accuracy assessment and uncertainty. Interagency Mapping and Assessment Project (IMAP) Users' Group: Portland, OR; February 2008.
	Grossmann, EB, JL Ohmann, J Kagan, KB Pierce Jr., HK May, MJ Gregory. 2007. Models for ecological systems map building: random forest and gradient nearest neighbor. Which one works best?. National GAP Analysis Program Conference: Asheville, NC; September 2007.
	Ohmann, JL, KB Pierce Jr., EB Grossmann, MJ Gregory, HK May, TM Holt. 2007. Current Vegetation Mapping in Western Oregon. Presented at: USFS Klamath Falls Ranger District: Klamath Falls, OR; June 2007.
	Ohmann, JL, MJ Gregory, KB Pierce Jr., HK May, EB Grossmann. 2007. Seeing the forest and the trees: harnessing GIS to map forests of the Pacific Northwest. Keynote address to GIS Day: Corvallis, OR; November 2007.
	Ohmann, JL, KB Pierce Jr., EB Grossmann, MJ Gregory, HK May, TM Holt. 2006. Mapping current vegetation in the Pacific Coast States with GNN, CART, and other tricks. Workshop and field tour with NF, ODF, TNC, and R6: Sycan Marsh Research Station, OR; September 2006.

Posters

	Roberts, HM, JL Ohmann, MJ Gregory, EB Henderson. 2012. Gradient nearest neighbor forest vegetation maps for landscape analysis and planning. ForestSat 2012: Corvallis, OR; September 2012.
	Roberts, HM, JL Ohmann, MJ Gregory, EB Henderson. 2011. Gradient nearest neighbor forest vegetation maps for landscape analysis and planning. US Regional Association of the International Association of Landscape Ecology Annual Meeting: Portland, OR; April 2011.
	Roberts, HM, JL Ohmann, MJ Gregory, EB Grossmann. 2010. Nearest-neighbor forest vegetation maps from FIA plots and geospatial data for landscape analysis and planning in the Pacific Northwest (and beyond). Forest Inventory and Analysis Symposium: Knoxville, TN; October 2010.
	Grossmann, EB, JL Ohmann, HK May, MJ Gregory. 2009. Mapping mountain hemlock and pinpointing ponderosa pine: Imputation mapping species distributions in Western Oregon. North American Forest Ecology Workshop: Logan, UT; June 2009.
	Ohmann, JL, MJ Gregory, HK May, EB Grossmann, RE Kennedy, WB Cohen, Z Yang, E Pfaff, M Moeur. 2009. Spatial monitoring of disturbance and late-succesional forest dynamics in the Pacific Northwest. US Regional Association of the International Association of Landscape Ecology Annual Meeting: Snowbird, UT; April 2009.
	Grossmann, EB, JL Ohmann, J Kagan, MJ Gregory, HK May. 2008. Context-dependent hierarchy of plant community predictors from the Oregon Coast Range to the eastern slopes of the Cascade Mountains. Ecological Society of America Annual Meeting: Milwaukee, WI; August 2008.
	Ohmann, JL, MJ Gregory, JD Kline, RJ Alig, HK May, EB Grossmann. 2008. Implications of social and ecological gradients for conservation planning in large, multi-ownership, forested landscapes. US Regional Association of the International Association of Landscape Ecology Annual Meeting: Madison, WI; April 2008.
	Davidson, A, T Miewald, JL Ohmann, J Kagan, EB Grossmann, T Sajwaj, J Aycrigg, S Lennartz, S McDonough. 2007. Methods and status of land cover mapping for the Northwest Gap Analysis Project. National GAP Analysis Program Conference: Asheville, NC; September 2007.
	Grossmann, EB, JL Ohmann, J Kagan, KB Pierce Jr., HK May, MJ Gregory. 2007. A tale of two techniques: Gradient Nearest Neighbor and random forest for mapping ecological systems in Oregon's Western Cascades. North American Forest Ecology Workshop: Vancouver, BC; June 2007.